Rear Differential Fluid Capacity?

[EddieC]

Anyone know the fluid capacity for the 10 bolt 8.5" rear differential in 2008 Tahoe? Not sure it matters but it's the G80 with 3.73 gears.
I read about the fill height and not how many quarts might be needed for a refresh.

Also, it's in the shop for bearing work and I wondered the consequences if they use conventional lube rather than the specified synthetic. I really hate to have shops work on our vehicles for just that reason.

 

[Foggy]

It's about 2.5-3 qts if I remember correctly. Yes, only use the Synthetic 75-90 Gear Oil

 

[OR VietVet]

Beat me to it ^^^^^^

Fluid: 12378261 or 88900401

 

[EddieC]

So the question remains, what if synthetic is not used being that I have no insight into the repair shop's procedures.
What would potential symptoms be before I replace the fluid with the GM spec?

 

[swathdiver]

Anyone know the fluid capacity for the 10 bolt 8.5" rear differential in 2008 Tahoe? Not sure it matters but it's the G80 with 3.73 gears.
I read about the fill height and not how many quarts might be needed for a refresh.

Also, it's in the shop for bearing work and I wondered the consequences if they use conventional lube rather than the specified synthetic. I really hate to have shops work on our vehicles for just that reason.

It's technically 2.15 quarts but GM says the level should be just below the opening to 3/4" below the opening. The range is given because after the vehicle is driven, fluid moves out into the axle tubes and takes time to drain back into the housing assuming it is on a straight and level ground.

if they put the wrong fluid in it, change it back and if its quiet, I'd call it good, unless someone has a valid reason for why it's not good.

 

[OR VietVet]

Symptoms would be like what @swathdiver said, noises. If it calls for synthetic, put synthetic in it.

"use conventional lube rather than the specified synthetic", is this what you think they will do? Just tell them to use synthetic.

 

[Tozan]

I just had my rear diff rebuilt a few weeks ago before my Colorado trip. The shop I took it to specializes in Differential work and they were insistent about using non-syn lube for break in as well as in the future and no GM additives.

I ran the non-syn for 1500 miles it was making a slight high pitch sound between 45 and 65 mph from the begining so, I switched to Lucas 80-90 Synthetic lube. The noise went away and the G-80 is still working fine when off road...

I have read a lot of pros and cons on using the GM spec oil with the conclusion it may not matter...

For the record my last set of gears / bearings failed after 80k miles running the recommended GM gear oil...

 

[EddieC]

We just got ours back this week. Transmission shop replaced main carrier bearings and axle seals. I asked if there was break in or fluid change in the near future and the answer to both was "no. The Invoice notes LS additive but not the type of base fluid. It sounded like a rock crusher before and is very quiet now. Some quotes wanted to replace everything in there to the tune of $1700 plus tax. The junkyard wanted at least that much for a junker with minimum 150k miles but that did include the housing and axles. The trans shop, who said they do tons of differentials of all brands, charged $470. There was 3 hours of shop time so they must know their stuff to get through it that fast.
So could your noise be related to no LS additive?

 

[Tozan]

They replaced all bearings, seals, ring and pinion gears in mine in a couple hours and I think they charged me $1150.00 for the job.