[luvthesmellofdiesel]

With all the posts about not having enough fluid in the axles from the factory and the fact that I have 30K on my '02, I figured I better change out the fluids on both the rear and front axle as well as the fluid in my ZF6 tranny...


So the questions are:





Rear Axle:


The service manual calls for GM12378261 (which meets GM spec 9986115). I understand it takes 5qts, Chev says it's $25/qt! Is this for real? Can't I just go to O'Reillys and pick up 5qts of Synthetic 75w-90 and be good to go? What about any friction modifier? I have the posi-rearend.





Front Axle:


The service manual calls for GM1052271 and 2qts. I don't see anything about any special GM spec for this one, so I assume I can pick up 80w-90 from O'Reillys and be good.





ZF/6 Tranny:


The service manual calls for Transynd GM12378515 (special order at the dealer ship BTW) for 6.3 qt's which is $18.30 a qt!





I want to have the right stuff in these but at over $100 each for fluid for the tranny and rear-end, clearly this can't be my only choice. What has everyone else done with this? Anyone changed out their factory fluids in their axles and ZF/6 tranny?


In the old days, you'd just grab the 75w-90 (or 80w-90 whatever it called for) and add a bottle of the friction modifier to it (posi rear) and be good-to-go. Is that still true?





Many thanks,


Tim

 

[dmaxalliTech]

Tim, grape juice or quality equiv in rear, 20 per qt for the gm stuff from me. Amsoil, Mobil 1 and other quality synthetics are ok.


front, plain ol 80-90 or a synthetic 75-90 that you use in the rear. be sure to switch the vent cap if you go synthetic


I have transynd for a lot cheaper then 18.00 per qt


Eric

 

[JimWilson]

Front and rear diff can take plain old gear oil or high-grade synthetic, so long as it's GL5 compatible (I'm using Mobil 1 myself). But I can't say for sure about the manny tranny because I have the auto. I doubt it's anything special or unique though.