1998 Chevrolet differential capacity (cannot find!

[TurboFiat124]

The Haynes manual and the owner's manual both say to use 80W90 oil in the differential but nothing about the capacity. In either manual!

Anybody have this data?

I have no idea what size differential is had but I can say it has the 5.7 liter Vortex and the 4 speed automatic (with the deep sump), 1/2 ton, referred to as "1500 Express".

Reason being I have an apparatus I rigged up where I can top off the exact amount, check the funnel every now and then, come back and refill.

 

[Farmer]

Isn't there a fill hole / inspection hole half way up the cover? That's your full line. If not there can be a plug on the side.

 

[Tman220]

Should have the 8.5" 10 Bolt rear in that Van, in which case capacity (according to the manual) is about 2 quarts, but will hold almost 3 (if you fill to the fill plug). GM along with other manufactures sometimes don't fill to max capacity, presumably due to cost, and less warranty replacements of seepy pinions seals.

 

[umungus1122]

Yes, it should be a little over 2 qts. to get even with the fill hole.

 

[dave1251]

About 2 quarts according to Amsoil.

http://www.amsoil.com/mygarage/vehiclelookup.aspx?url2=1998+CHEVROLET TRUCKS+G1500 VAN+R

 

[Nick1994]

I had the same truck, but 1996. I bought 2 quarts of gear oil and refilled it. It didn't ooze out by the end of the 2nd quart, but I could feel it with my pinky. So slightly over 2 quarts. Ideally you want to fill it until it starts to drop out. But mine was full enough.

 

[Chris142]

Quarts
Rear W/ 10.5 RG 3.2
Rear W/ 8.5 RG 2.1
Rear W/ 8.6 RG 2.4
Rear W/ 9.5 RG 3.0

 

[TurboFiat124]

Unlike my automatic transmission, I'm not too concerned with overfilling the differential. Usually whenever oil started pouring out the filler port is when I pull the hose out. The only reason I asked this was so:

A: Didn't have to run back to the parts store to buy more
B: Return any full bottles I did not use

It seems I have to know what size differential I actually have before hand. And the owner's manual doesn't say. Like the above post there can be up to four differential sized differentials used on this van.

I bought two bottles so in total I have three in addition to the full bottle I already have.

Also this isn't the "rule of thumb" but seems to apply to Subaru, Ford and Chevrolet. If the differential calls for GL-5 80/W90, it has a standard differential. If it calls for 75W/90 Synthetic, it has a limited slip differential.

The Haynes manual says if my van was built after 2005 to use 75W/90 so I'm assuming begining in 2005, GM started using limitied slip differentials on these vans/trucks.