Differentials

[Vince]

What is the recomended mileage to change the oil in the front and rear diff's of an '04 TB? Also, is the Mobil synthetic OK to use? I'm thinking I am going to do these my self to save a few bucks. Is there anything special I should know before doing it? Capacities?

[ENVOY2LOW43]

I'm not so sure but i guess its around 60,000... :undecided ...i recall for my expedition it was recommended at 100,000 miles (but again not sure)...i gotta go check the manual... :undecided

[MoJoe]

I do 25k on the transfer case. diffs, and tranny. Every 25k. I do not care what the manual calls for unless it calls for sooner. :m2: You can use any brand fluid, as long as it matches the manufacturer specs. I use Amsoil in my diffs.

[Jman423]

I tried to look in the 04 TB manuals in the resources section, but it looks like GM changed the links to the 04-05 TB OEM manuals without Tommy knowing it... :m2:

[02EnvoySLE Guy]

I do 25k on the transfer case. diffs, and tranny. Every 25k. I do not care what the manual calls for unless it calls for sooner. :m2: You can use any brand fluid, as long as it matches the manufacturer specs. I use Amsoil in my diffs.

Agreed. Especially on trucks with the G80 package, it wears down that fluid QUICK. :undecided

[sallen]

i put mobile syn in my diff, the dealer here recommends doing it within the first 6,000 and then every 25 k, dont know if thats right but thats what i am doing to mine i want mine to last so i do a ton of maint speaking of which i think i am almost do for a oil change, hmm

shay

[Dave]

What is the recomended mileage to change the oil in the front and rear diff's of an '04 TB? Also, is the Mobil synthetic OK to use? I'm thinking I am going to do these my self to save a few bucks. Is there anything special I should know before doing it? Capacities?

This is a big question on the Cadillac CTS forums. GM says in the 03 TB manual;


Front and Rear Axle
SAE 75W-90 Synthetic Axle
Lubricant (GM Part No. U.S.
12378261 I in Canada 10953455) or
equivalent meeting GM Specification
9986115.

GM replaced 8261 with a new PN. It has a grape scent to it. There isn't ANY dif oil on the market that "meeting GM Specification 9986115" besides the GM grape scent stuff. The CTS does mention using limited slip if you have the locking rear, TB does not. There is a "possibility" GM can deny your warranty claim if they don't smell the grape stuff.

There are a lot of better performing and cheaper fluids. AMSOIL, Lucas, Mobil are 3 I can think of of hand.

Tranfer case uses the Autotrax II Fluid. This is according to an 03 TB manual. If you don't do much 4 wheeling I would guess changing the rear often is more important than changing the front.

[MoJoe]

The front drive shaft stays in constant motion with Autotrac, only the hubs are unlocked, that is why these 4wd's you want to do both at the same time. At least it does on the fullsize rigs, this 4wd system may differ, but I doubt it knowing GM :D . That is why when you lift an Autotrac equipped GM, you need to swap the driveshaft out if going over a 4.5" diff drop, or you may get vibrations due to the angle on the stock front shaft since it stay spinning even in 2wd. I lifted 2 of my Silverado's and 1 Tahoe and had to do this.

I think this is correct info, I am on meds right now for being sick, so excuse my temp insanity :D

[Vince]

Thanks for all the replies guys. I'm pushing 20k on my '04 and I haven't done the diff's yet. I'll probably do them some time later in the summer. Looks like I'll be OK using Amsoil or Mobil synthetic.

[o2man98]

Guys/Gals,

I would highly recommend using the Amsoil Severe Gear in your differentials. Seems to be working great with the G80's in both my Silverado and the wifes Trailblazer with no additives.

This is all I have used since I became an Amsoil Dealer. I was completely surprised at the difference when I switched. Even my wife noticed, see said she has to use her brakes more to come to a complete stop. Also seems to not be as stiff up here in Wisconsin during the winter.

Ken

[ParadoxJr]

Wisconsin winter??? You mean you guys have Winter in the US?? :laugh: hehehe I am at about 25K miles, and I doubt the previous owner ever change the diff or the tranny fluid. do you think I should change them??? I have the G80 Package..

Russ

[o2man98]

Yes, you have me beat with the winter thing.

I changed both of mine at 10,000 miles and them were pretty dirty looking.

Ken

[ScarabEpic22]

o2man98-
Thanks for the confirmation on the benefits of using AMSOIL severe gear lubes. I just became a perferred customer, and will order my gear lube within a week. I was wondering whether or not to use an additive, but now I will definately not do so.
You answered a question that I didnt even post, my be psychic or something! :D

[o2man98]

Great,

If anyone else would like a Preferred Customer Membership contact me and we can work it out.

Also, please contact with any questions.


Ken

[Jman423]

What would a diff fluid change cost anyway? :confused:

[MoJoe]

What would a diff fluid change cost anyway? :confused:


With syn fluids and if you have the G80, around $75-$100 for both here. It is easy to do these yourself. They have drain and fill plugs.

[Sinecure]

This is a big question on the Cadillac CTS forums. GM says in the 03 TB manual:
<snip>
There is a "possibility" GM can deny your warranty claim if they don't smell the grape stuff.
<snip>


That's BS. If GM decides they can void your warranty for using a competetor's oil, then BY LAW, GM must provide their special non-warranty voiding oil free-of-charge to all consumers who own vehicles of which requires said oil.

[Dave]

That's BS. If GM decides they can void your warranty for using a competetor's oil, then BY LAW, GM must provide their special non-warranty voiding oil free-of-charge to all consumers who own vehicles of which requires said oil.

If your oil does not meet GM specs than it they can deny warranty claims. Chrysler does it with their ATF.

You can compare it to a part. A competitors part may fit and be cheaper but if it causes a warratied part to fail, they can deny your claim.

I asked Cadillac if I can use mobil 1 or lucas in my Caddy, that way at least I'm covered.

The law your are talking about was talked about a lot on the Corvette forums. An aftermarket rear end company requires a specific oil otherwise your warranty is void. Someone mentioned the law you are talking about, but it didin't apply.

Will Chevy deny your warranty claim if they dont' smell the grape scent? Probably not! But if you don't have proof what was put in, you may be in trouble. Face it! Some dealers are crooks also.

[Jman423]

.........Face it! Some dealers are crooks also.
SOME dealers.....? :x

[jimmyjam]

LOL. Dealers.. man... reminds me of the time I test drove an Avalance and the dealer tells me that he got 32mpg on a trip to Georgia. "You've got to think I'm the dumbest person in the world to beleive that" Never went back there again.

[02EnvoySLE Guy]

LOL. Dealers.. man... reminds me of the time I test drove an Avalance and the dealer tells me that he got 32mpg on a trip to Georgia. "You've got to think I'm the dumbest person in the world to beleive that" Never went back there again.

what?! Not even the biggest moron on the planet would think 32MPG was achievable in an Avalanche!! :m2:

[Jman423]

what?! Not even the biggest moron on the planet would think 32MPG was achievable in an Avalanche!! :m2:
You would be surprised what some people would believe.... Its sad!! :(

[Envoy Fan]

LOL. Dealers.. man... reminds me of the time I test drove an Avalance and the dealer tells me that he got 32mpg on a trip to Georgia. "You've got to think I'm the dumbest person in the world to beleive that" Never went back there again.

Sounds to me like a fill up or two that did not get figured in the MPG ;)