trans fluid ?? 100k change ? [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: trans fluid ?? 100k change ?


LOWRIT00
09-22-2007, 01:09 PM
I was in the local auto zone today, picking up some plugs and detailing stuff, and one guy had said if you havent changed the trans fluid at 40-60k
dont change it at all, I wasnt so sure about that, seemed weird. I heard him explain, that the old fluid with all the centiments (sp?) actually help the trans shift with that many miles, :confused: If you do change it that late, you just asking for problems after you do it. So question is, from me over hearing this guys talk about this, he the one correct, will it cause problems ? or should it be changed no matter what ?

bigkeyz
09-22-2007, 01:17 PM
I've heard that too but dont believe it. I have bout 90k and am planning on doing the flush soon. I just dont see how crap in your tranny could make it work better..

LOWRIT00
09-22-2007, 01:20 PM
yea me either, I still plan on doing the change. kinda like not changing your oil, but the topic had me puzzled

MajesticLT03
09-22-2007, 01:31 PM
its true.. I did my first tranny flush on my old bonneville at 98K and around 102K it needed a new transmission.. all hell broke loose after the change..


I havent changed my tranny fluid in my TB yet and its sitting at 65K right now.

BLAZEN03
09-22-2007, 02:22 PM
I too have also heard of that, but still skepticle! I worked at Autozone for 6yrs & dealt with many top ASE tech's, I also being ASE P2 certified, & have never heard of "just leave it" as a good idea. Seems like that's the rumor around here though. I have 60,xxx mi & plan on doing mine within the next 3,000 mi, with my next oil change.....:confused:

exttb
09-23-2007, 10:52 AM
well if worried just do drain and change no flush....I have 155,000 on my original fluid and everyone around here said as long as your tranny works perfect it should be ok to change but if its acting up a little it may go after the change..

from a old timer .....


.Basically, at higher mileage - it's a crap shoot. From my actual experience, 90% of the time, you extend the life of your tranny. 10% of the time, you precipitate a failure (specifically the clutches). You'll know within a short period as your tranny will quickly begin slipping as the fresh fluid and additives eat away the varnish and deposits holding the clutches together. The reality is, if changing the fluid precipitates a failure, you were probably on borrowed time anyhow.

My advice: if you're at 100k or so and haven't changed the fluid yet -
Do it if you can afford a rebuild, odds are good that you'll buy yourself some time.
Don't if you can't afford a rebuild but start saving for one.

exttb
09-23-2007, 10:55 AM
from another source(at least my fluid still looks red and smells normal)

Well being in the tranny bussiness for over 20 years heres what I have observed , I have seen perfect working transmissions with dirty looking fluild but working perfectly fail within hours of a fluild an filter change , Tearing them down afterward while i havent really seen the clutches come apart I have seen them badly burned , and the reason seals that had literally broken up , Generally black fluild means hardened seals , new fliud with its detergents and better viscosity and generaly the higher flow rates with a new filter just literaly break them up , But also this should be bore in mind also ,
Generally unless your a proper maintenence kinda guy , Most people dnt even think about changing there fluid till the think theres a problem and ussually there is by then , So when they change the fliud its a pointless attempt at fixing the problem way to late , Its like changing the oil because the engine starts knocking , too LATE
www.performabuilttransmissions.com

Aerostud1026
09-23-2007, 11:52 AM
Wow, I just changed mine last week at 49k.....good thing I didn't wait any longer....:undecided

Jozuah
09-23-2007, 02:57 PM
i changed mine at 53K and was getting a little slippage when interstate crusing and giving say... 20% throttle to pass it would shudder a bit then shift, i now have EXACTLY 100,020 miles and will be changing it again this week , the trany all but felt new after the first change. i had a shop do it so i could actually look at the valve body and se if there were any nasty looking things , and the magnet was SO/SO clean , excited to see the magnet now :)

Josh
P.S. i drive hard , but no stalling , so the fluid gets to move around alot.

i will take pictures and make an article (did a brakes one it was fun)

bullethole
09-23-2007, 03:47 PM
Here is my experience over the last 35 years. I usually did not change the trans fluid but checked it often to make sure it was still red and did not smell burned. NEVER had a trans failure or problem. I bought a 97 Jeep GC 4x4 which is service intensive. Trans. 40k, front & rear diff. 40k, transfer case 40k, many grease fittings on the steering and drive train. I performed these right on the money. Bottom line. Had trans. rebuilt twice and rear diff. once in 110k. No off road wheelin or rough driving. Unlucky? Maybe, but it does point to leaving the trans alone. My wife's Honda Accord has 225k on the clock and the trans shifts like new. Replaced the fluid twice. It is just a drain and fill, no filter. My 02 has only 50k and I plan to let that dog sleep.:cool:

LOWRIT00
09-23-2007, 04:32 PM
So what if I drop the pan, clean, pan and magnet, leave the filter there and re-install the pan and fill with new 5 quarts of syn trans fluid, or should I just do it all anyway? I changed my s-10 out at 90k and drove it till I sold it at 130k, well now Im mixed on it, F8ck:hissy::duh::hissy: I feel I should changed but dont want problems or a rebuild.

I might just have to leave the trans dipstick out and drive it for a week, and as everyone said "let it burn"

I dont know anymore, I just have to talk with my Uncle and see what they do at the Proving Grounds, with the tbs with 300 + k on them.

Jozuah
09-23-2007, 09:40 PM
i belive that the fears all arise from the ford AXOD transmissions. in the AXOD if you went to long and then changed the fluid you would expect a failure soon. so the shops and even some dealers in my experience were telling folks to leave it and "start looking for a rebuilt" or "save for a rebuild". the Type F fluid also comes to mind , the fluid was gritty by nature and abrasive? maybe even to the point of saying gave more grip, i can remember using Type F for GM products and calling it the "poor mans" shift kit.

ask the dealer or your uncle, or just change the fluid as its stated in the OM and follow the OMR on fluid changes, then youll have no worries.

as for your problem, if it were mine (and it has been) i would change it IF the fluid is not burnt up or smelling like fish.
if its red and still not burnt up , i would think a web poll would show that 95- 99% of people would say change it..

just my :m2: worth ,
josh

LOWRIT00
09-24-2007, 01:12 AM
yea, I pretty much set on changing it this week, Its just when you hear something like that, you start second guessing yourself and it sucks, cause if I hadnt hear that convo, it would have been changed saturday morning, no questions asked. but what can you do. bottom line Im changing it this week.

thanks again for all the great input and info
gotta love this site:thumbsup:

mysonsspoiled
09-24-2007, 01:18 AM
used to work at aamco trans and they said that it is bad to flush a system if you havent done it and your vehicle has 80-90K. But you can do a drain and fill ie drop the pan, change the filter clean off your magnets and pan and refill with fluid. My old car was done every 30K like clockwork, and never slipped, and drove that thing like it was a manual. I just changed all my fluids (engine, trans, differentials) to amsoil Ill never have to change them again. The only thing i couldnt swith was the transfer case because gm says use autotrakII fluid only

LOWRIT00
09-24-2007, 01:27 AM
Yea Im not doing a flush, just dropping the pan, changing the filter and adding 5 quarts, then adding the trans cooler and calling it a day,

exttb
09-24-2007, 09:20 AM
after thinking about this.. if our fluid is red and smells normal than a drain and fill no flush should be ok.I have 156,000 on mine and I will give it a shot I would really like my filter to be changed

LOWRIT00
09-24-2007, 12:28 PM
and come to thing about it, I wont be towing the four place enclosed snowmobile trailer anymore:no: with my Voy, only the two place will be hooked up to it. :yes: I dont rag on my trucks, so I shouldnt have a problem, and if I do then it was just time to rebuild or replace the trans, that just means I can drive it for another 100k with no major problems. :D

ilikemy3s
09-24-2007, 12:28 PM
Bought my 04 Enoy this past March with 36k on it. Had the fluid changed at about 38k. Plan on changing it again at 60 to 65k or transcooler install (which every comes first)

carp
09-25-2007, 04:08 PM
I was planning on doing a line pump out, pan drop & filter change soon. I am at 63k. Maybe instead I will just drop pan, change filter, install tranny cooler and fill with the 5 qts or so of new fluid. My fluid is still red and is not burnt smelling. One note however, I noticed on my tranny dipstick it was always reading about 1/3 qt overfull since I bought it(used). Now I never added any fluid to it, but obviously someone did. Maybe it was changed, the pan looks like it has never been off. So if so, it was flushed I guess. Anyway I made a home made vampire pump & sucked out the 1/3 qt or so and got it down to the correct level when hot,(just slightly below the full hot mark). It seems to shift better now in all gears. I will still do the pan drop/filter change soon, but do you guys advise even doing that with 63k?

pvgoheelsunc1
09-25-2007, 11:25 PM
Sure, Go for it. At 63k you will need to do it in the next 10k anyway. Then your looking at a flush out at 70k since you bought it used. 13 qt and filter line flush might be $55-60 DIY and piece of mind.

HammerJw
12-06-2007, 03:59 PM
Ok,

I was all ready to do a Trans flush this weekend on my TB with 89K,

But after reading this post, I'm a little gun shy about it. I haven't ever changed the fluid in her.

I can say I think I had a very hard shift the other night when I was going about 35 and had to merge quickly..... I HAMMERED down, and once it got past the lag the engine reved very high, and I felt a slight slam as it shifted.

I have a PCM4Less tune... but I thought that was suppose to fix the problem.

Anywho, any and all advise on if I should flush, or just change would be great.

brinks90
12-06-2007, 04:33 PM
in my opinion, i would change it. i have changed tranny oil in my 1990 chevy lumina every 90,000 and now have 246,000 miles on it and still shifting as smooth as the day a i got it. I put LE oil in it. I am going to do the same with my 2000 monte carlo pace car replica. it has 51,000 miles on it, and almost 8 years old, so i am going to flush it, and I will do the same with the trailblazer transmission and differential. i got the directions on how to flush out the whole system. it takes two people because you are adding the new oil and pumping out the old oil out of the converter, If you do a total flush, our trailblazers take almost 3 gallon of tranny oil.

HammerJw
12-06-2007, 05:21 PM
WOW! 3 gallons!

Thanks!

agates1272
12-06-2007, 05:51 PM
I will tell you from personal experience that if you've neglected your tranny and haven't been cosistent with the maintenance, you run a SERIOUS risk of failure if you flush it. Case in point:

When I managed a Pep Boys, we flushed an s-10 blazer with over 100k on it. Drove in fine, but after the flush, the tranny wouldn't engage. We ended up buying a new tranny for it and eating the cost. We made it a rule after that that unless the customer signed a waiver releasing us from liability, we wouldn't do flushes or tranny oil changes on the vehicle.

It's a fact that a neglected tranny will have alot of metal and sediment suspended in the fluid, which will give the friction needed to shift. Remove the old fluid and that sediment, and you're going nowhere. Unless you're under warranty, I wouldn't risk it.:nono::suicide:

iznit
12-06-2007, 06:11 PM
I will tell you from personal experience that if you've neglected your tranny and haven't been cosistent with the maintenance, you run a SERIOUS risk of failure if you flush it. Case in point:

When I managed a Pep Boys, we flushed an s-10 blazer with over 100k on it. Drove in fine, but after the flush, the tranny wouldn't engage. We ended up buying a new tranny for it and eating the cost. We made it a rule after that that unless the customer signed a waiver releasing us from liability, we wouldn't do flushes or tranny oil changes on the vehicle.

It's a fact that a neglected tranny will have alot of metal and sediment suspended in the fluid, which will give the friction needed to shift. Remove the old fluid and that sediment, and you're going nowhere. Unless you're under warranty, I wouldn't risk it.:nono::suicide:

Are you recommending that this member with 89K on his tranny not change the fluid & filter nor should he flush? :confused:

Jozuah
12-06-2007, 06:18 PM
Are you recommending that this member with 89K on his tranny not change the fluid & filter nor should he flush? :confused:

if the fluid is burnt and brown smells all nasty, and you towed alot, and you have never changed your fluid and your at 100K+ miles, save for a new tranny first or yeah dont do it. if its been neglected and you change it very possible you have a no go condition.
Josh

agates1272
12-06-2007, 06:36 PM
Are you recommending that this member with 89K on his tranny not change the fluid & filter nor should he flush? :confused:

It's a coin flip. Changing the filter and cleaning the pan is the lesser of the two evils here. The thing is, it's not guaranteed that flushing will harm the tranny. But I have seen it happen firsthand. So my suggestion is, if you haven't serviced the tranny at the required intervals, or you bought your vehicle used and are unsure whether it was serviced at the required intervals, don't do it.

The hard shift he had could be a good indication that there is a problem, especially if he's used it for towing or driven it really hard. The fact that it hasn't had any transmission maintenance performed in 89k miles is a good indicator, too. I would say start saving for a new tranny and don't touch the filter or the fluid. Probably couldn't hurt either to remove some fluid and add some Lucas to it....

Just my :m2:

robin13
12-06-2007, 07:28 PM
I've often wondered if just replacing some of the trans fluid every second or third oil change would keep the fluid fresh and avoid a major maintenance hit. You'd do it with one of those sucker devices that folks use to change the oil on boats. Just stick the very thin semi-rigid line down the tube where the dipstick goes as far as it would go. I think you'd get four or five quarts out (that's what I got out of a Taurus). Measure carefully what came out and put the same amount back in. Realize that you'd never change the filter or see the magnet or condition of the valve body, but you'd constantly have pretty clean fluid.

HammerJw
12-07-2007, 01:34 PM
So,

what's new tranni going to run? Aprox?

Ben98gs
12-10-2007, 04:09 PM
A LOT of money... Then if you have it installed at the dealership a LOT MORE money.

To give you an idea, the MSRP on the transfer case is $1,785 and that does not include installation. (I could not find the price on a replacement tranny quickly).

okhmbldr
12-12-2007, 06:40 PM
I was quoted $2500 from the local chevy stealer. I had the dealer flush at 70,000 per their recommendation. At about 95,000 I noticed that on long trips driving through the hills with lots of up and down shifts that the overflow was throwing out some fluid. It never leaked during in town regular driving. The dealer said it needed to be overhauled at a cost of $2500. It still shifted great no other problems. I decided to change the fluid myself and noticed that the pan bolts and gasket had never been removed. So, that meant that the filter had never been changed. I changed the filter, added five quarts, and after a long trip up and down the hills, NO LEAKS!. I would recommend regular changes, no flushes, and include filter replacements.

exttb
02-15-2008, 10:04 AM
ok I changed the pan fluiid(5 quarts) and filter at 169,000...shifts much better now...only time will tell...thiis was my first change was brown but didnt smell burnt

06TBLZR
02-18-2008, 04:33 PM
For the high mileage TB try using an additive like Lucas trans care.

When I was racing my supercharged 67 camaro with a 700R4 trans( same as the TB trans just not controlled by a computer) at the local drags,the trans started to slip, I put 1qt of the of Lucas trans care in and the trans stopped slipping and I was able to finish racing. The fluid is made to restore worn clutches. I did need to rebuild the trans, but for the TB with high mileage, that are not being used as race cars, this fluid might let the trans live longer and not fail after a flush.

Just my:m2:

06TBLZR
02-18-2008, 05:01 PM
Just to give you an idea on price:
I did not use a dealer.

The transmission shop that works on my 67 camaro with 500hp that has a TH700R4 trans, charged me $900.00 to build a trans that would hold up to the HP my car has. I pulled the trans out myself.

The same shop also rebuilt the trans in my 1998 3/4 ton chevy pu, for $1600.00 they pulled the trans and installed more clutches and a shift kit for better holding power and firmer shifts when towing.

My point is sometimes the dealer is not the best place for the job, I got a better transmission for less money

If you live in California: The shop's Name is: TRC Transmission 818-822-0082 Chatsworth CA ask for RON

silver ghost
02-19-2008, 02:42 AM
im glad i poked around in this forum, because i was thinking of changing the trans fluid and filter.my dad told me never flush the trans.63000 miles:)

jdmctrek9
02-19-2008, 05:23 AM
i was poking around too. i bought my TB (02 LT) two months ago and everything is great. but i just wanted to throw it out there that these trannys do go bad, some way sooner than others. i bought my TB with 69K on it, but the tranny had gone out at 49K. the total cost including the trans cooler was $3000. this was done at a place called COTTMAN TRANSMISSION, ive never heard of this company. but nevertheless... the tranny went out at 49k!!

i found out later that my SUV use to be a rental vehicle. and the people that sold it to me were an older couple that towed a lot. but im surprised that a tranny with 49k can go out so soon, regardless of how it was driven.

im happy. i got a good deal on the TB. and i feel like i have one less issue to worry about since the transmission i have now is practically brand new.

so my question is: theres 20k on this new transmission. what is the best way to keep it in top notch shape? should i flush it or just change fluids at say... 30k from now (90,000 total miles)

tbon221988
05-30-2008, 07:04 PM
i was poking around too. i bought my TB (02 LT) two months ago and everything is great. but i just wanted to throw it out there that these trannys do go bad, some way sooner than others. i bought my TB with 69K on it, but the tranny had gone out at 49K. the total cost including the trans cooler was $3000. this was done at a place called COTTMAN TRANSMISSION, ive never heard of this company. but nevertheless... the tranny went out at 49k!!

i found out later that my SUV use to be a rental vehicle. and the people that sold it to me were an older couple that towed a lot. but im surprised that a tranny with 49k can go out so soon, regardless of how it was driven.

im happy. i got a good deal on the TB. and i feel like i have one less issue to worry about since the transmission i have now is practically brand new.

so my question is: theres 20k on this new transmission. what is the best way to keep it in top notch shape? should i flush it or just change fluids at say... 30k from now (90,000 total miles)




http://youtube.com/watch?v=d2ZcJGxQiGw

check this out.
rental trailblazer

HeaderHopeless
06-09-2008, 05:01 AM
I was real hesitant at first about changing the transmission fluid/filter on my 02' trailblazer, but when I was having my transmission checked *because I have 102,000 and the tranny has never seen service* I guess four of the linings were rusted or something so I had those replaced along with getting new tranny fluid /filter. I didn't take it to the dealership. I took it to a transmission shop and was only charged $410 for everything. As of now, I can tell you the new tranny fluid/filter have really smoothed out my shifts and everything. No problems yet. :tiphat

ffbacker
11-05-2008, 12:08 PM
I just bought an 05 EXT with 66000. No clue as to how it was treated prior to my ownership (bought from a dealership), although the trailer hitch appears like it has never been used (no scratches in the paint, knicks, etc.), and it runs like a dream. Trans fluid is red and odorless (as far as burnt is concerned). After reading all this, I'm still leaning towards a flush and filter change, to be on the safe side, unless a swarm of you tell me otherwise. No problems shifting whatsoever. What type of fluid do you recommend? Manual says DEX III, but I've read some here about Dex VI..... and what about synthetic? which would work best in your opinion(s)?

Thanks in advance!!!

Robert1101
11-06-2008, 11:24 AM
There is a thread about how to change almost all the fluid without a flush. I am not fond of the power flush idea and the dealer wants $200.00. Dex IV is synthetic. I put on a Hughes +2 quart finned pan (with drain plug) and put in 7 qts of fluid. In 5K miles I will change the fluid again which will almost remove all the dex 3. The fluid/filter should be changed about every 50K. Also the antifreeze should be changed 5yr/100k, as well as all the other fluids, (front and rear differental, transfer case).

Johnboy_mr2
11-12-2008, 08:25 PM
I was in the local auto zone today, picking up some plugs and detailing stuff, and one guy had said if you havent changed the trans fluid at 40-60k
dont change it at all, I wasnt so sure about that, seemed weird. I heard him explain, that the old fluid with all the centiments (sp?) actually help the trans shift with that many miles, :confused: If you do change it that late, you just asking for problems after you do it. So question is, from me over hearing this guys talk about this, he the one correct, will it cause problems ? or should it be changed no matter what ?

I believe this MYTH can be attributed to the proper transmission fluid being used. Due to the long span of miles between recommended trans fuild changes, there can be differences in the oils which make them incompatible. I've never had any issues as long as I've replaced the fluid drained with that listed in the Owner's Manual. Any deviation from the recommended fluid leaves you at the hands of your own fate. Machinery needs clean oils at all times to lubricate seals/metal to metal contact, etc. If it makes sense, it's probably the right thing to do. Change the fluid as stated in recommended maintenance intervals.

GM has spent millions and possibly billions to date trying to engineer the best fluids for their parts. Some other brand/type/viscosity/detergent levels is not always the best route. Many who have replied have done so because they have had tranny problems. Not many would be interested in the thread if they had not experienced any problems.

Hopefully this won't totally kill the thread as there are other topics to be discussed.

My2cents,

JD:thumbsup:

Blazernut
11-14-2008, 01:23 AM
:iagree: The only thing to add is that if you changed it and you had gone a long time on the fluid before the change then change it again after a very short service interval.

I can't see high quality clean fluids ever being a detriment to the moving parts. The only problem would be if the gaskets and seals are already dried out and leak prone.

:m2:

stopher2
11-18-2008, 05:48 PM
It's a coin flip. Changing the filter and cleaning the pan is the lesser of the two evils here. The thing is, it's not guaranteed that flushing will harm the tranny. But I have seen it happen firsthand. So my suggestion is, if you haven't serviced the tranny at the required intervals, or you bought your vehicle used and are unsure whether it was serviced at the required intervals, don't do it.

The hard shift he had could be a good indication that there is a problem, especially if he's used it for towing or driven it really hard. The fact that it hasn't had any transmission maintenance performed in 89k miles is a good indicator, too. I would say start saving for a new tranny and don't touch the filter or the fluid. Probably couldn't hurt either to remove some fluid and add some Lucas to it....

Just my :m2:

I've read that the hard shift is typical of this transmission. it is called whiz-pop (or some type of enimonapia). The problem with mine appears to have this too. it is when a servo is dirty and doesn't shift. mine is from 1st to 2nd. I am ambivilent on changing fluid due to this conversation. OTOH, I am hopeful that changing the fluid will clean off the servo and stop the "slightly" hickup shift to 2nd.

stopher2
03-01-2009, 10:26 AM
I've read that the hard shift is typical of this transmission. it is called whiz-pop (or some type of enimonapia). The problem with mine appears to have this too. it is when a servo is dirty and doesn't shift. mine is from 1st to 2nd. I am ambivilent on changing fluid due to this conversation. OTOH, I am hopeful that changing the fluid will clean off the servo and stop the "slightly" hickup shift to 2nd.

I finished a job of the water pump, et al. I disconnected the battery while i did the job. When I connected the batter the problem of the whiz-pop disappeared for 20 miles !

This leads me to believe the problem is a PCM issue. I am now ready for a computer tune because this is BS.

Alternatively, I am wondering if anyone has experience with Seafoam Transmission ? Would this cause more problems cleaning out the seals or would it clean off my servos and fix my problem ?

calhoun
03-11-2009, 05:29 PM
I have a 2003 TB LT bougth it a little over a year ago. Got it from a dealer, dont know if the scheduled maintenance had been done or not. I was planning on replacing the pan, filter, and changing the fluid. Did not plan on doing a complete flush. After reading some of these threads its sort of hard to decide whether or not to go forward with this. I fully believe in maintenance to prevent problems. If there is anyone that has changed their fluid after 83,000 without changing it prior please let me know if you have any problems .. To let you know I have not had any probs at all so far.

10856
03-11-2009, 06:07 PM
I changed my fluid and filter(but not the flush) at 89,000 for the first time, I am the original owner and I have never towed anything and have been relatively easy on the truck. the fluid was getting dark but lacked the burning smell that has been mentioned here, I used castrol dex VI and I am planning on changing just the fluid again in a couple months due to the fact that I only got out 5 qts with the first change, the trucks shifts a little smoother now , I would like to think because the clean filter is allowing the fluid to move easier........next job is the transfer case fluid:tiphat

Menthol
04-04-2009, 01:37 PM
ok I changed the pan fluiid(5 quarts) and filter at 169,000...shifts much better now...only time will tell...thiis was my first change was brown but didnt smell burnt

Update?

2fast4ya
04-09-2009, 04:11 PM
update?

+15465654

TannerLTZ
04-12-2009, 12:52 PM
So I just bought my TB less than a month ago with 70k on it, not sure if it has had any service on the tranny or not, but i doubt it. From what I have read here so far it seems most are leaning towards dropping the pan and swapping the filter and adding new fluid as opposed to the flush? Also I see alot of poeple recommending that you use DEX VI, would there be an issue with mixing that with the original DEX III thats in it already, as would happen with dropping the pan and swapping the filter???

Menthol
04-12-2009, 05:16 PM
So I just bought my TB less than a month ago with 70k on it, not sure if it has had any service on the tranny or not, but i doubt it. From what I have read here so far it seems most are leaning towards dropping the pan and swapping the filter and adding new fluid as opposed to the flush? Also I see alot of poeple recommending that you use DEX VI, would there be an issue with mixing that with the original DEX III thats in it already, as would happen with dropping the pan and swapping the filter???

See posts #2 in this thread

http://forums.trailvoy.com/showthread.php?t=53387&highlight=backward+compatible

91RS
04-12-2009, 05:56 PM
If you know it's been kept up, then you'll be fine with a flush no matter what the mileage is. If you don't know the service history and the fluid doesn't look like it's been changed, just do a service (drop pan and change filter) and NOT a flush. GM actually does not have a flush in the maintenance schedule, but it is a good thing if done correctly and at the right time. I have no problem with a flush, but I don't think any additive should be added to the transmission. I would say if you wait until 50k, do a service THEN a flush at the same time.

TannerLTZ
04-13-2009, 09:53 PM
See posts #2 in this thread

http://forums.trailvoy.com/showthread.php?t=53387&highlight=backward+compatible

good info, thanks man

superwally88
04-29-2009, 04:06 PM
Hey all,

I just want to post on how well the transmission flush procedure worked for my TB at 90,000 miles and never having maintenance done to the transmission. Believe me... when you start becoming curious about transmission flushes, there is a great concern whether or not to perform this crucial operation on your "prized" vehicle. I was juggling around the issue for a month before I decided to go against the current and take "the risk." How about I just tell everyone who is curious about doing this that if you don't have burnt fluid (smells like burnt varnish - stinks real bad), and the color is not dark brown (mine was reddish/rust colored on dipstick - which I find is exaggerated since the drained fluid was more reddish/purple and closer to a normal color), you should perform this flush. I will however state that if you do have issues with slippage or harsh shifts or no shifts at all... don't waste your time/money doing this first (check your valve body or clutches, then do a flush after the appropriate repairs). I found that not only does my vehicle run cooler, but I have lower rpm shifts which are almost seamless unless running through the gears to get to highway speed on an on-ramp. Three points of advice are: 1) You do not need to move anything to drop your pan, just angle it to the passenger side and to the rear of the vehicle to get around the heat shield and the shift linkage; 2) Perform the flush before you switch out filters... this will prevent the system from getting clogged after the flush since the old filter will have all the junk caught from the flush instead of chancing it with the new filter; 3) Concerning the cooler line: remove the belt shield for better access, have a 2 1/2" vinyl tube about 10' in length for positioning a bucket by the driver side door to conduct the flush, make sure that the engine is turned off when the fluid begins to "spit" out the tube and that you add just as much that came out, and run more fluid through... even though you think it looks good. I ran 11 quarts to flush, then dropped pan and changed filter (only 1/2 inch of fluid in pan), then cleaned pan and reattached, then connected cooler line, added 5 quarts and shifted through all the gears while at a standstill, and finally drove it... checked fluid... and topped off with 2 1/2 more quarts. Oh, and I used Castrol Dexron VI. Job took less than 2 hours, and I have benefited greatly from a much better ride for almost 3 months now (no abnormalities or transmission grenades that all opposing parties describe). It will also improve the life of your valve body... which, sad to say, will fail eventually in the 4l60e!

puffer
11-16-2009, 09:50 PM
I know its a old thread but i did a total flush and filter at around 130k and no probs at 160k+.

07 Black Envoy
11-16-2009, 10:07 PM
I know it's not the same vehicle, but I had a 2000 Buick Regal and changed the transmission fluid a little over 100k and sold it with about 140k and had no problems at all.

Fluid didn't even look dirty.

I have already changed it on the Voy (around 54k) and don't look to have to do that again for some time now.

badkittyfurball
11-29-2009, 05:02 AM
There seem to be lots of different opinions about a transmission fluid exchange/flush and filter replacement.

I have a 2003 Envoy that has been a STELLAR vehicle. Currently I am closing in on 105,000 miles and (knock on wood) have had fabulous service from my vehicle. Recently I did the normal high mileage replacement stuff (front brake pads at 102,000, water pump and thermostat at 90,000). I have taken pretty good care of my vehicle. I get the oil changed regularly. Unfortunately I haven't had the transmission fluid serviced since approximately 25,000 to 30,000 miles. I took it to my mechanic to have the oil changed the other day and he suggested a transmission fluid exchange. The tranny is not slipping, does not hesitate and shifts up and down through gears fine. The fluid is not burnt smelling and is not dark. I know mileage wise it should be done, but my dad is old school and told me "if you don't do it every 25,000 to 30,000 miles, then you should not do it AT ALL!". I'm concerned that the fluid exchange will CAUSE problems and after reading ALL the information in all the different threads about what to do, now I'm even more confused.

I have an appointment with the mechanic on Thursday for a fluid exchange, not a flush but am REALLY SCARED about doing it.

Suggestions or handholding anyone?????

:thx

91RS
11-29-2009, 10:09 AM
When you did it at 25-30k miles did you just drop the pan or did you do the fluid exchange then? Either way I would definately say you're safe to drop the pan and do a filter change. I did a fluid exchange on my mom's Tahoe at 80k miles or so to change it out to Amsoil, I dropped the pan probably 10k miles earlier to change the filter and filled it with Dexron VI at that time. It had no services before that and everything has been fine.

skilled2k1
11-29-2009, 10:24 AM
I have a 2002 Tblazer. I became the second owner of it at 88k miles 3 years ago when I was 20. Earlier this year I started doing alot fluid changes, and finally got to the transmission fluid change. It was at about 136k miles, and from the look of the fluid and the service records I had, it had never been changed prior. The tblaze was shifting very sluggishly, and after much reading about everyone's thought on the matter for the such a high mileage change, I went and did it. I did a complete flush, pan drop and filter replacement using GM Dex 6. The difference was AMAZING! It was like having a completely different truck.

Mind you my situation was bad. 136k without a trannyfluid change, PLUS almost every year of its life the tblaze towed boats semi frequently in the summer. I decided to change the fluid because I felt given my situation, that I should expect the transmission to fail at 150k, and had planned for replacing it anyway because I plan on keeping the trailblazer til 200k miles. I figured it was worth a shot to maybe extend the transmissions life.

As I said the difference in performance was dramatic for me, and so far Im at 152k miles and the transmission feels great.

badkittyfurball
11-29-2009, 03:19 PM
Thanks for the info. At the 25,000 mile mark, it was just a fluid exchange. I didn't drop the pan and the filter wasn't changed. This time I am planning on an exchange of fluid and a filter change. I haven't really towed anything with my truck and after reading the last thread about the 136k change and having towed a boat, I'm hoping I'm going to be okay. It needs to be done, regardless.

Thanks everyone!:thumbsup: I'll let you know what happens after a couple of weeks.

Trailblaze_2002
11-29-2009, 04:11 PM
:offtopic: My brothers 2003 Dodge Ram 1500 with 187,000 miles on it had the tranny start slipping (no supprise there) and we changed the fluid and filter now it shifts fine. So i wouldn't think that doing it to my TB would hurt anything considering my bros Dodge had the original fluid and filter in it and we all know how Dodge trannys are. My TB currently has 180,000 and i'm gonna do a fluid and filter change soon. The fluid and filter change actually helped his stop slipping. So we'll see how it goes for the TB later on.

91RS
11-29-2009, 08:49 PM
Thanks for the info. At the 25,000 mile mark, it was just a fluid exchange. I didn't drop the pan and the filter wasn't changed. This time I am planning on an exchange of fluid and a filter change. I haven't really towed anything with my truck and after reading the last thread about the 136k change and having towed a boat, I'm hoping I'm going to be okay. It needs to be done, regardless.

Thanks everyone!:thumbsup: I'll let you know what happens after a couple of weeks.

Yeah, you should be fine for both.

TannerLTZ
12-03-2009, 01:20 AM
Well my 02 Tb has just under 90k on it now, and at about 74k I dropped the pan and changed the filter. After this the slightly rough shifting i experienced when the truck was cold seemed to get worse. I decided I would do a flush and try to add some Lucas to see if that would help at all at about 79k. I bought the truck not too long ago and dont think anything had been done before that. Im starting to think Ill be looking at a new Tranny soon.:bonk: probably would have turned out the same even if i hadnt done the fluid change I think though.

91RS
12-03-2009, 08:00 AM
Well my 02 Tb has just under 90k on it now, and at about 74k I dropped the pan and changed the filter. After this the slightly rough shifting i experienced when the truck was cold seemed to get worse. I decided I would do a flush and try to add some Lucas to see if that would help at all at about 79k. I bought the truck not too long ago and dont think anything had been done before that. Im starting to think Ill be looking at a new Tranny soon.:bonk: probably would have turned out the same even if i hadnt done the fluid change I think though.

There is a PCM calibration update to address cold shifting issues.

TannerLTZ
12-03-2009, 10:27 PM
There is a PCM calibration update to address cold shifting issues.

Really... is that a dealer fix? like a recall or should i expect to cough up some $$$ to get that done?

91RS
12-04-2009, 08:00 AM
Really... is that a dealer fix? like a recall or should i expect to cough up some $$$ to get that done?

You'll have to pay probably and hour labor, some dealers may charge less but don't pay more than that.