introduction and some questions

first off ill introduce myself, im john, i just turned 18 and i live in ohio.
I own a black 1996 jeep grand cherokee limited 5.2L v8 with 128xxx miles and absolutely love that thing. my mom has a 96 2 door 2wd tahoe with about 148xxx miles in a dark blueish color.
ill post up some pics of both rides soon :)

couple questions.
what weight oil should i use for my moms hoe and how many quarts?
also, what weight rear differential fluid do these take? and how much
while im at it, are there any common problems associated with my moms generation tahoes?
also what rear axle does my moms tahoe have?
and does it have an LSD? (i dont think it does but thought id check)
im not new to working on cars, as i have worked on my jeep before (mantenaince, small mods, nothing major), but i have not done very much regarding my moms tahoe.
thanks in advance
john

Welcome to AF!

I believe 5w/30 is the reccomended weight. If it has an owners manual, look in there for the reccomended weight for a specific temperature. In most newer engines (unless otherwise specified) 5w/30 can be used year-round. Using the lowest weight specified will give you the best gas mileage.

The weight of gear oil will depend on the differential. Most are 80w/90, although some require a synthetic oil, usually 75w/140. Capacity will also depend on the differential. On a Tahoe, probably 2-3 qts... I don't think they put anything larger than a 12 bolt in them.

To find the rear differential, you need to count the bolts holding the ring gear to the carrier. Fourtunately, the number of bolts in the rear cover will be the same in this case (and almost every modern vehicle).

The easiest way to check whether or no it has a LSD is to jack up the rear axle (block the front wheels) and try to rotate one wheel. If you can rotate it by hand (transmission in park), it either does not have a LSD, or the clutch packs are severely worn. You could also check the RPO codes in the glove box, but I couldn't tell you what code is limited slip.

In the 1997 model, the codes are as follows...G80=limited slip differential, GT4=3.73 ratio, GU6=3.42, and GU4=3.08.

Welcome to AF!

I believe 5w/30 is the reccomended weight. If it has an owners manual, look in there for the reccomended weight for a specific temperature. In most newer engines (unless otherwise specified) 5w/30 can be used year-round. Using the lowest weight specified will give you the best gas mileage.

The weight of gear oil will depend on the differential. Most are 80w/90, although some require a synthetic oil, usually 75w/140. Capacity will also depend on the differential. On a Tahoe, probably 2-3 qts... I don't think they put anything larger than a 12 bolt in them.

To find the rear differential, you need to count the bolts holding the ring gear to the carrier. Fourtunately, the number of bolts in the rear cover will be the same in this case (and almost every modern vehicle).

The easiest way to check whether or no it has a LSD is to jack up the rear axle (block the front wheels) and try to rotate one wheel. If you can rotate it by hand (transmission in park), it either does not have a LSD, or the clutch packs are severely worn. You could also check the RPO codes in the glove box, but I couldn't tell you what code is limited slip.
thanks for the welcome.
are there different axles on the tahoes?
or were there just different axles depending on year/generation?
ill go give it a look, and of course, do the old trusty spin the wheel test :)

There are different differentials... the term "axle" usually means the assembly of the differential, axle shafts, tubes, rear cover, shock/spring mounts, and flanges. The differential may have different size tubes on it depending on the size of the ring gear, and different tubes may have different mounts, etc. But it all goes by what size ring gear and number of bolts the differential has.

From memory, I believe the rear has a 10- or 12-bolt option, but I think there were several diameter ring gears.