Transmission Service Yes or No

[AndrewB]

I've hear this wives tale more than once and wanted to hear everyone's take on it.

If you do not service your transmission regularly, you should not service it at all. The reasoning behind this is that the gunk and stuff that comes out when you do to transmission service is actually keeping everything together. Does anyone else obey this rule?

Now on to my personal experiences.

1. My GMC Typhoon had about 108K miles on it when I serviced the transmission (pan drop). The previous owner had no record of changing the fluid and he had it about 30K miles. Well about 1K miles after the service the 2-4 band broke and it needed a rebuild, no signs of problems before I changed the fluid.

2. 89 Mazda 626 200K+ miles, had a bad pan gasket leak on the transmission. I decide to replace the gasket and filter and about 3K miles later the transmission did not want to shift into first any more, cause unknown.

What I'm trying to get at is this just me or are transmissions that tempermental? On both vehicles the fluid levels where dead on and filled with the correct fluid.

Do I change the fluid on my TB? I was going to flush, pan drop, fill 4-5 qts, flush, then top off. My truck has about 76K on it with no previous record of a transmission flush.

Sorry for the novel, I just want to avoid another expensive transmission rebuild.

[MTPockets]

A 2002 @ 76K is not too out of line. It's been my experience that if the ATF does not look black/burnt and the trans worked perfecly going into it, a pan drop or fluid transfustion wont hurt a thing. If you are not comfortable, do just a pan drop and filter change, some time down the road do another dump and fill or a transfusion.

Joel

[RayVoy]

Years ago nobody changed the fluid. I didn't, but I did change a few transmissions. My last 5 or 6 vehicles (GMs) were run for 250,000 miles, fluid changed every 50,000. No trans problems. Sure, trans are better today, so is the fluid and the cooling of the fluid but I think changing the fluid saved my trans. We also know heat is the biggest enemy of the auto trans and that getting stuck and spinning tires is a quick way to generate heat. Maybe the best friend the auto trans has is the 4 wheel drive transfer case. No spin, no heat, no fried tranny.

[Hootbro]

If gunk, sludge, metal shavings and the unknown are keeping a high mileage tranny together, then you are on borrowed time anyway. I think the risk is higher to keep old stuff in rather than flush and replace with new.

Hootbro

[Mean_I-Sixer]

So is it better to flush or just drain and refill every 50K? I thought 1 flush would be ok, but too many would hurt.

[Blueblazed]

I think your personal experiences are coincidental. As someone else said, a neglected transmission is on borrowed time anyhow.
Something else to remember - in regards to the "old wives tail" sometimes people are having trouble with their tranny - such as slipping in a gear, rough shifting or whatever and in an attend to "fix" the problem they try a fluid change. Shortly thereafter the transmission fails and they blame it on the servicing of the transmission - not taking into account that the transmission had a mechanical problem to start with.

That being said I agree with Joel. I would change it. GM recommends 100k for normal use, but I think that is just too long. I like to change mine about every 30K or 2 years. My 05 is coming up on both those figures, which I will probably do right after Thanksgiving.

Good luck!

[blu ya]

I think your personal experiences are coincidental. As someone else said, a neglected transmission is on borrowed time anyhow.
Something else to remember - in regards to the "old wives tail" sometimes people are having trouble with their tranny - such as slipping in a gear, rough shifting or whatever and in an attend to "fix" the problem they try a fluid change. Shortly thereafter the transmission fails and they blame it on the servicing of the transmission - not taking into account that the transmission had a mechanical problem to start with.

That being said I agree with Joel. I would change it. GM recommends 100k for normal use, but I think that is just too long. I like to change mine about every 30K or 2 years. My 05 is coming up on both those figures, which I will probably do right after Thanksgiving.

Good luck!

:iagree:

On both of my vehicles (02 Grand Prix GTP and 03 TB) I have changed the fluid and filter around 30k. I believe in preventive upkeep. :yes:

[MTPockets]

A simple pan drop to clean out the junk in the pan and magnet & fluid replacement will put you miles ahead of an unserviced trans. May as well replace the filter while you are in there, but I've never seen a filter with anything on it (on a good trans anyway), just slight discoloration from being submersed in hot ATF . Fluid swaps or transfusions thru the cooler lines are popular because they are super easy to do, non invasive and major money makers for shops. Do they put you further ahead than a pan drop/filter change? Hard to say. They typically cost more.

Joel

[AndrewB]

Also I forgot to ask about using Dexron VI in my TB vs. Dexron III?

[MTPockets]

If dex 6 is backwards compatible, go for it! Dex 3 with an H spec is what my 2005 4L60E specs.

Joel

[blu ya]

If dex 6 is backwards compatible, go for it! Dex 3 with an H spec is what my 2005 4L60E specs.

Joel

Just pick some up, and it states it is backwards compatible. Going to be doing a pan drop (fluid and filter) tomorrow on the GTP.

[rrmccabe]

I've hear this wives tale more than once and wanted to hear everyone's take on it.



Afraid I will have to agree.

I have put a lot of miles on work trucks, vans etc and never changed the fluid. The trucks I did service ended up having transmission issues shortly after.

Although I wont do this on the SS, I am almost a believer in doing everything but tranny service !

[jimmyjam]

in my last truck I got a flush done at around 175k miles and as soon as I pulled out it was slipping so bad it could barely move. at that point the tc is gone and needs to be replaced regardless. as was stated, it might buy you another 10k miles to leave the chunky fluid in there but a trans rebuild is inevitable. I'd rather just keep the fluid fresh from the get-go

[ScarabEpic22]

Well, this might explain why Im having trans issues with my TB. Did a pan drop/fluid refill at 49K, then a complete flush/drop/refill at ~59-60K. Been having slippage issues in OD ever since, although I have finally been able to tune some of it out (but I dont like the fact the hard parts still arent working properly).

Ohh, well, I might just reflush my trans with Dex VI and not use Amsoil syn ATF instead in the spring.

[RichKotite]

Since we are on the ATF changing theme, does anyone do the full purge instead of dropping the pan and changing 3 quarts....Makes sense to purge it all to me.

[Spong]

I've always serviced my trannies every 30k. I usually do the pan drop with new filter the first service and then the machine flush at 60k. I like to alternate service methods each time.

I also like to add Lube Gard
http://www.lubegard.com/automotive/trans_atf.html

[Dave]

Ask yourself one question. Why do you change the engine oil? Wouldn't it be better to leave it in there to not risk exposing leaks?

Trannies can be even more picky then engines since they need the fluid to operate. I have mine drained and purged with a filter change at 50k miles.

It is pretty easy for most of us to fall in GM's severe service requirements for tranny fluid. Unless you drive where it is not too hot, not too cold, flat and you don't get stuck in traffic.

[Nukedog]

Every 60K...

[NotForBling]

Will NOT changing the tranny fluid affect your warrenty or aftermarket warrenty?? I would assume that GM would look at these things if a tranny went prematurely and they had to do warrenty work. Just wondering. GM is pretty stingy when it comes to warrenty work.

I just spent a ton on changing all sorts of fluids and would like to think it was worth it :yes:

[bullethole]

Almost 100k on my TB and no trans service yet. Did the transfer case at 50k because of some 4x4 issues. Previous ride was a 97 Jeep GC. By the book this vehicle was service intensive. I serviced the transmission, transfer case and front and rear diffs like clockwork using the best lubricants money could buy. Had two trans rebuilds and one torque converter in 150k. The rear end went out at 112k. Seems the more often I serviced it the more trouble I had. Decided to let sleeping dogs alone on the TB and see what happens. I still may change the trans fluid at 100k.

[rrmccabe]

I am not sure I could ever recommend to anyone not to do tranny service.

But as I said above, I can honestly say I have had issues when I did. Why? I have no idea.

On the other hand I would never consider not changing engine oil, that is stupid and I have seen the negative effects tearing down engines that have been poorly maintainted.

So all I am going to say at this point is there is something to what AndrewB said. Even if I don't understand why.

I am still going to change the fluid in my SS as recommended intervals and hope for no issues. At least I wont be able to put blame on myself.

[Blueblazed]

I still think we are dealing with an "old wives tail" here. For example, on my Ford I changed the filter and the fluid at 25K. Safe bet I was the first one to do it. I bought a new filter, and filled it back up with fluid. Checked the fluid level, looked good. Took it out for a test drive, NOT good. It would go into 1st gear real slow, slip a lot, and then take forever to shift into 2nd. At a stop sign it would kick into neutral and when I'd give it the gas it would gradually slip back into first.
Called a couple of friends, who really weren't much help. At that time I had no other vehicle available, so I took the pan back off, put the OLD filter back on (it didn't look too bad to start with) filled it with fluid again - everything was hunky doory! No more problems. That was almost 10 years ago. Same transmission, about 4 filter changes later it's still working great.
Upon further inspection, I found where the o ring goes on the filter - it was out of round. Obviously the filter had been dropped or mishandled. I returned the filter and got a new one. But in the mean time, I left the old one in. We were leaving on a long trip, and I decided to leave well enough alone.

The point is, sometimes there are other reasons for transmissions "failures". I really can't see how changing the fluid could cause a transmission to fail. Granted, I'm not a transmission mechanic. Maybe if there is one out there, he/she could explain it to us!

I have to agree with Dave this time, most of us fall into GM's severe service category. My book recommends 50K for that, so a vehicle that went 108K would be considered severely neglected. I personally think that is an optimistic number. I believe Joel changed his a while back at the 25k mark (correct me if I'm wrong)

Some of the old transmissions could go practically the life of the car without service, but the modern ones don't seem to be able to do this. A friend of mine had a van with 80K on it, had a couple of minor shifting problems. The dealership said "You know, that' s a lot of miles on that transmission. You are lucky to make it that long" I'm not going to mention the name because I don't want to start an "us vs them" discussion.

I do know heat is the enemy of ANY tranny, and I can't believe old "yucky looking" fluid could possibly cool as well as new stuff. My :m2:

[MTPockets]

...I believe Joel changed his a while back at the 25k mark (correct me if I'm wrong)..

Yep I sure did. Right around 20Kmi I did a pump out thru the cooler feed. My TB was a rental, so I wasnt going to be happy until I had all my own fluids in there..:eek: I used a case of NAPA ATF. Somewhere around 30-40K, I'll drop the pan to do a clean-out and maybe change the filter. When the pan is off I will definately install a drain plug on the pan so I dont have to mess with those darn push/lock cooler line fittings. Man I hate those!

Joel

[rrmccabe]

I do know heat is the enemy of ANY tranny,

Agreed, I think if you keep the fluid at a decent temp it will last a LONG time.

[triz]

Someone correct me if Im wrong according to Chevy the only recommended service at 50K is the transfer case service...everything else is 100k, 150k. Thats what the service at Chevy said. All the other fluids are Synthetic (differential) Coolant is I believe 100k or 150 cant remember.

[torker]

I did my 91 Caprice at 59.000 and added a tranny cooler at the same time. Towed a light popup camper through 15 states, always in drive. Oh I also installed a taxi/police radiator too. 185,000 when I sold it and still strong. HEAT is the enemy..not a too late change of fluid. I just had my 91 Blazer flushed at 185,000 mi. been over 10,000 since then.

[Blueblazed]

Someone correct me if Im wrong according to Chevy the only recommended service at 50K is the transfer case service...everything else is 100k, 150k. Thats what the service at Chevy said. All the other fluids are Synthetic (differential) Coolant is I believe 100k or 150 cant remember.

Maybe they changed it from other years, but for my 2005 my owner's manual recommends "change automatic transmission fluid and filter" at 50K for "severe service" They define "severe service" as "In heavy city traffic where the outside temperature regularly reaches 90F or higher, in hilly or mountainous terrain, when doing frequent trailer towing, uses such as found in taxi, police or delivery service"

I'll be the first to admit the wording is vague. For example: what does "frequent trailer towing" mean? You tow a trailer once a year, once a month, once a week? Also, wouldn't the distance you tow a trailer make a difference? If I tow a small UHaul around town for 10 miles, that's obviously not the same as towing it 1000 miles! What does "regularly reaches 90F" mean? Once a month, every day of the month, etc...?

Many times people spend a lot of time and money changing their oil to protect the engine, but don't think of changing the tranny fluid, when the tranny is a very expensive item to replace as well. As Dave said the tranny is more "picky"

[The Black Pearl]

Changed the transmission fluid (full flush and new filter), diffs and transfer case at 63,000km. I was told I should have done this at 40,000km. Expensive but worth it in the long run. The transfer case oil was due according to the tech. I might just do the transfer case and diffs every year and the transmission (transfusion) every second year.

[Rob]

Changing the fluid is not going to damage a transmission, unless it is absolutely on its last legs. I once had a guy drive his vehicle in with a problem. We dropped the pan and it was full of sludge and the fluid was way burned. He didn't want to do anything. We put the pan back on and put the same fluid right back in. It would barely move at that point, even though we hadn't done anything. He tried to blame us for ruining his transmission. The BBB told him to take a hike.

Tranny fluid does not deteriorate over time like engine oil. As long as the tranny has been kept cool, and nothing foreign has contaminated it, and there has been no mechanical failure, the fluid will last forever. I never changed the fluid on my GMC Safari, and I towed a 5K pound boat all over the place. Sold it with 160K miles on it and it was still working fine. That said however, I would still follow the manufacturers recommendations. I've been meaning to do my Suburban for months now (60K or so), and plan to do my TB when it gets to 50.