Rear end oil change

[Pcpurvis]

I have a 02 Yukon SLE 5.7L, 4 speed automatic transmission. Do I need to add limited slip additive to the gear oil? Also I want to verify the gear oil is SAE 75W90 Synthetic (GM spec 9986115)
VIN: 1GKEC13Z42R299363
Thanks In advance

 

[swathdiver]

I have a 02 Yukon SLE 5.7L, 4 speed automatic transmission. Do I need to add limited slip additive to the gear oil? Also I want to verify the gear oil is SAE 75W90 Synthetic (GM spec 9986115)
VIN: 1GKEC13Z42R299363
Thanks In advance

That old number from your owner's manual, 12378261, has been superseded by 88900401 or 10-4016. Your axle takes 2.15 quarts and requires no limited slip additive.

 

[nonickatall]

That old number from your owner's manual, 12378261, has been superseded by 88900401 or 10-4016. Your axle takes 2.15 quarts and requires no limited slip additive.

I think he meant "limited slip" for the automatic transmission. You don't need this.

Just use Dexron VI for the transmission and 75w90 for the differentials.

You should also exchange the oil of the transfer case. But for the Yukon you need for the transfer case AUTO Trak II I guess.

 

[MassHoe04]

I think he meant "limited slip" for the automatic transmission. You don't need this.

Just use Dexron VI for the transmission and 75w90 for the differentials.

You should also exchange the oil of the transfer case. But for the Yukon you need for the transfer case AUTO Trak II I guess.

Thanks for that other information, but the OP's question is regarding the rear differential.

If this is a G80 rear end, the G80 does not have any clutch discs and does not use any limited slip additives in the gear oil.

 

[Pcpurvis]

I think he meant "limited slip" for the automatic transmission. You don't need this.

Just use Dexron VI for the transmission and 75w90 for the differentials.

You should also exchange the oil of the transfer case. But for the Yukon you need for the transfer case AUTO Trak II I guess.

Thanks for the information; I’ll change out the tranny fluid and filter once I have corrected the ABS phantom and replace the knock sensors and harness ( both are still throwing intermittent codes after my second round of “fixes”). I’m changing the rear differential fluid today and just Needed a confirmation that I didn’t need the limited slip additive.
Thanks again.

 

[B-train]

Nothing wrong with lubing the rear end properly.......always makes stuff work better. LOL

 

[nonickatall]

Thanks for that other information, but the OP's question is regarding the rear differential.

If this is a G80 rear end, the G80 does not have any clutch discs and does not use any limited slip additives in the gear oil.

That is my bad English, because he wrote about the transmission and questioned for the oil change. I thought he want to change transmission oil and differential oil.

 

[swathdiver]

Thanks for that other information, but the OP's question is regarding the rear differential.

If this is a G80 rear end, the G80 does not have any clutch discs and does not use any limited slip additives in the gear oil.

There certainly are clutch discs in a truck G80. The GM formulation negates the need for limited slip additive.

 

[MassHoe04]

There certainly are clutch discs in a truck G80. The GM formulation negates the need for limited slip additive.

OK.
I am always learning!

I was under the wrong impression, that the mechanical pawl system was something that eliminated use of any clutch.

I have learned the G80 does not use any limited slip additive. I mistakenly thought it was because of the mechanical nature of the pawl setup GM used.

The difference between this and other forums is that our members here are big enough to admit being wrong, learn something new and still come out friends in the end.
I was wrong my friend... Thanks @swathdiver !

 

[MassHoe04]

That is my bad English, because he wrote about the transmission and questioned for the oil change. I thought he want to change transmission oil and differential oil.

Kein Problem! (If that phrase is wrong or offensive, I'll blame Google Translate. I don't actually speak German.)

P.S.: Keep photos coming once in a while when you have a reason. The countryside and villages are beautiful! Amazing place!!! You must really enjoy tooling round in the Esky...