Angry Johnny

I'm just getting more confused on my D70 limited slip differential about what fits and what doesn't. I know I have a 32 spline D70 in my 92. But,
Is it a Trac Loc or a Power Loc?

Some sites have clutch kits for D70/D80 diffs as the same and others show the D60/D70 to be the same. I know the '96 2500 gasser D60 diff I pulled the axle out of in the junkyard had a narrower axle shaft than the '98 2500 diesel D70 that was in there. At least I assume it was a D70. It was an automatic truck but I'm unsure if it was 12V or 24V, the engine was long gone.

So now I'm unsure if the diff out of the 98 is the same as my 92. I just want to get new clutches and steels for mine as they are worn out. I was going to use the 98 diff in case I needed anything else in there.

So if someone could enlighten me on these I would appreciate it.

Thanks.

oliver foster

That '98 if it was an auto Cummins truck should be a Dana 70. Only the dually and manual 2500 came with the Dana 80.
The Dana 80 has a telltale neck down at the ends of the axle tubes where they mount to the brakes. They basically use Dana 70 brakes on a Dana 80 axle with the bigger 4 inch IIRC tube.

Angry Johnny

The axle tube was about 3.5", maybe 3.5625".

I just took this carrier apart and I believe I see what is making the noise in mine now when making a turn. Dang it, needs more than clutches. lol

Angry Johnny

The ring gear side looks OK. I'm sure this is causing the noise that sounds like something is rolling around in the bed when going around corners. The spider gears roll on this part.

Angry Johnny

Those kits aren't cheap either. lol

u2slow

The 60 and 70 powr-loks use the same guts... except the side gear spline varies (30, 32, 35). It used to be common to mix & match pieces in order to have a 35-spline D60 powr-lok for a front diff.

What's confusing is the D80 trac-loks also uses a split-case design like the powr-lok so they look very similar to the untrained eye. I don't know if the 2ndgen D70 adopted this design or not; also don't know what fits what with this design.

Before you go spending a bunch on rebuilding a 32-spline posi, think long and hard if that diff is what you want for the long term.
- older D70s are 35 spline
- C&C D70 is a closer width match for the front
- a lunchbox locker is very price competitive with powr-lok parts
- 2ndgen diffs don't take much to bolt in - nicer brakes, wider, larger studs, Dana 80 if desired.

Angry Johnny

Well, the lunch box locker looks like I would need an open diff carrier to start with. I don't have that. I already have disc brakes on the 70 and since it's lasted over a quarter million miles already, and still works, I think it will be OK for me. Thanks for the info though. I appreciate it.

u2slow

Discs... nice

I went the Dana 80 route because my springs and hangers were shot too. Dana 80 swap - westcoast style - RamchargerCentral.com