2006 GMC Sierra 1500 4x4 Axle Fluids

[marc1]

Hi,

This is a copy of the axle recommendations from the manual for this truck:

Front Axle (1500 Series)
SAE 80W-90 Axle Lubricant
(GM Part No. U.S. 1052271, in
Canada 10950849).

Front Axle (1500 HD,
2500, 2500 HD,
and 3500 Series)
SAE 75W-90 Synthetic Axle
Lubricant (GM Part No. U.S.
12378261, in Canada 10953455)
meeting GM Specification 9986115.

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

My truck is just the regular 1500 not the HD model. I am wondering if anyone knows the reason why the standard front axle doesn't take the same fluid as the HD front axle and the rear axle. Is there a special reason why GM specifies regular non-synthetic 80w90 out front? There was some noise on the Internet about seals leaking but it wasn't backed up with any TSB's or good arguments beyond the standard "synthetics leak" rumour etc. I used Red Line 75w90 in the front (and rear) of my 1996 K1500 for over 200,000 miles with no problems and was hoping to do the same here. The Red Line is fine for the rear axle based on the manual information... just not the front for some reason.

 

[Trav]

I don't know specifically but i am guessing that they expect the HD units to be doing more 4x4 work like plowing etc hence the synthetic lube recommendation.
I would just run the synthetic 75w-90.

 

[xxch4osxx]

I use Amsoil Severe Gear 75w90 synthetic in the front and rear diffs on my Silverado and have no leaks at all. I wouldn't worry about it.

 

[Whimsey]

It's just a cost savings for the manufacture to use the minimum spec fluid from the factory that will do the job for that particular vehicle. The extra cost for the synthetic fluid is minimal for one vehicle. However, using it for the factory fill for thousands/millions of vehicles can add up. Especially if the less expensive fluid will work for that vehicle, at least through the warranty period.

I used a better front diff fluid in my F-150 with no problems.

Whimsey

 

[marc1]

Hi,

Does anybody have access to this TSB they can post? Do you know if it is also applicable to 2006 models?

#05-00-90-010 titled Revised Front Drive Axle Carrier Lubricant Information

Thanks,

Marc

 

[Trav]

I have it here its a picture,but its only 1999-2005.
Basically all front axles from the S10 up can run the 75w-90.
Given there is a TSB about growling from the front axle including 2006 i would run the synthetic 75w-90.

 

[marc1]

Originally Posted By: Trav
I have it here its a picture,but its only 1999-2005.
Basically all front axles from the S10 up can run the 75w-90.
Given there is a TSB about growling from the front axle including 2006 i would run the synthetic 75w-90.


Thanks I appreciate this. By the way, do you know what the "growling" one is about?

 

[Trav]

I just spoke to a friend of mine who has been a GM mechanic for 40 yrs.No issues whatsoever running 75w-90 in the front axle of the 2006 as a matter of fact he believes it to be a better choice.
This is the growl issue TSB.

 

[marc1]

Originally Posted By: Trav
This is the growl issue TSB.


Super thanks again, I really appreciate it.

 

[meep]

just did a buddy's late model tahoe. put M1 syn 90wt in both axles. rolls a little more quietly and he's seen a very slight increase in mpg averaged over several weeks by the trip computer.

We debated what to do with the t-case. He has the one with the optional selectable full-time AWD. We thought about a HFM ATF but ultimately settled on the "blue" t-case fluid from GM. Maybe $7 per quart.

CHANGE THIS FLUID. The old stuff came out as thin as water (tho it looked clean) at 50k miles. There was a good bit of driveline noise that went away when we swapped out that fluid. The chain in that T-case must beat it up pretty good.

M

 

[marc1]

Revising this thread as I have a new question.

I rotated the tires today and while doing the job I was surprised to find out this truck has the 8.625" ring gear in it. It is a normal all original unaltered since new 2006 5.3L 3.73:1 Z71 like the other thousands out there but I am pretty sure my old 1996 K1500 Z71 had the 14 bolt cover (9.25" RG). I searched the Internet a bit and yes, this 8.625" RG 10 bolt is the normal 1500 axle in the new trucks. Does it hold up as well under light truck duty work? 8.625" seems a bit small for truck duty. My old 96 had the 6600 GVWR package I wonder if this is why it had the heavy axle in it? This new truck is only a 6400 GVWR (C7H) with the usual GT4 / G80 combination. Any thoughts on the reliability of this smaller axle?