Differentials - Replace Or Rebuild - Pay The Man Or Do It In The Driveway

Is there anyone here that has actually set one up? It is like a black art that is spoken about in whispers and hushed tones. I have "set up" a couple out of necessity (have to get to work the next day) but I really did not know what I am doing and both hummed a bit but lasted 100K without any issues. Measurements were taken with vernier calipers off the housings and I did look at the tooth pattern with some marking paint.

The easy button has always been to just go get a new axle or center section or in the Porsche 944's you just got a new trans with the diff attached.

For now, let's keep it simple and discuss the basic solid axle rear ends. Are there good instructions out there for setting these things up? Is it one of those things that you really have to do and get a feel for? Or is it one of those things that "paying the man" really is the correct option.

The reason I am asking all this is my truck has a Dana 60 in it and it has been humming a little but it has been doing it for the last 100k miles without any change. Eazy button is to either go get a used complete rear end or have a shop (that can prove they know what they are doing) rebuild mine.

The not s easy option is for me to try and rebuild it. I have complete confidence in getting it apart. Where things get messy is putting it back together. The whole setting it up part.

But how hard can it be? Do you need a pile of special tools or just a couple good measuring gauges? Will you spend a pile of $$$$ on shims that you will never use again or are they cheap?

Just looking for some input from those that have had some experience with rebuilding rear diffs and what is realistically do it at home and what should be left to a pro.

Stan just helped me do mine. So glad he did because there's a lot of little stuff I didn't even know about. But after doing it, I'd do it again.

Reading the instructions on set up are the intimidating part.

Actually , with the close manufacturing tolerances of the bearings and gears, things are not that difficult.

Getting the preload on the pinion bearings is the probably hardest part.

Just did it on the triumph race car. I'm all for adding new skills. Go for it. The toughest part I had to deal with was building a case spreader tool. The set up itself wasn't bad at all.

pay the man! I hate differentials its always so sensitive and everything is greasy and sharp. For advanced diff repair you need a hydraulic press which is a no-no tool for me.

I paid for my first one, the second time i saved a bunch of money by having an old man teach me. Its alot of measuring and checking things too make sure its correct. The directions that were included pretty much spelled it out but i wasnt going to try it on my own. Proper tools are the biggest help.

I rebuilt the 8.8 IRS in my RX7.

I'd pay someone if I had to do it again.

Its worth doing it yourself if for no other reason than it makes your hands smell awesome for a couple days.

gearheadmb wrote: Its worth doing it yourself if for no other reason than it makes your hands smell awesome for a couple days.

This^

It is one of those jobs that you want to do if you want to know how to do it. Otherwise, the first time is a long process and may or may not be perfect. Dial indicators are cheap. The pinion pre-load is a pain and requires a press with a bearing holder./

If you are detail oriented and like to follow processes, then you are in luck.

NOHOME nailed it. If you WANT to know how to do it, then absolutely dig in. I personally find it tedious enough that I have someone else do it, and I wrench for a living.

If you have a 9" Ford, go for it! But you don't, so never mind.

If it's been humming for a hundred thousand miles, why are you worried?

If you're talking about rebuilding the clutch packs, that should be pretty simple, in that you should be able to put it all back together the way it came apart.

The last time I paid someone to look at my diff, it was because it had a lot of "snatch" in it, and I specifically wanted him to verify the backlash. He held the pinion and moved the ring, said, "Looks allright to me," and charged me $50. Six months later, I took it apart myself, put a dial indicator on it, and found .035". I had to scrounge up some used shims (which I then had to "full custom" them with a concrete block) to get the backlash and preload into spec.

Wow .035 the one Bob and I set up .006. This was the 4th rear set up. If you can assemble an engine you can do this.

stan_d wrote: Wow .035 the one Bob and I set up .006. This was the 4th rear set up. If you can assemble an engine you can do this.

Thats true, my same comments about everything is greasy and sharp can also explain building a rotary but I have no problem with that lol.

Differentials are one of the most reliable assemblies on a car. In over 40 yrs. of wrenching repairs were minimal.

Spider gears were the biggest, then an occasional bearing failure. Ring and pinion were rare.

Curious as to what the reason for the repair on those reported on here.