rebuilding an 8 3/4

[Dreamcar]

This is something I've never done before. I also want to change gear ratios. Is this something I should try to do myself? Are there any good guides I can follow? Who are the best parts suppliers? Any insight is appreciated. Thanks

[Dino]

This is something I've never done before. I also want to change gear ratios. Is this something I should try to do myself? Are there any good guides I can follow? Who are the best parts suppliers? Any insight is appreciated. Thanks

Changing the center section is easy enough.  But I'm not one to play with the actual gears and adjustments.  The FSM has good instructions.  I don't know about suppliers, most of mine are CL and ebay, ubt everyone seems to like Dr. Diff.

When I drop the T56 in my car, I would love to have a true trac.  Best of both worlds!

http://www.doctordiff.com/8-3-4-eaton-truetrac-differential.html

The hardest part of the axle is setting the bearing preload.  Search this site for how to's or replace the bearings with green bearings and discard the adjuster.

[fy469rtse]

Got a factory service manual, read up on how to do it again and again, do your research on the best components
For your needs, I understood it, I knew what components I needed, I'm by capable but still had to get a good friend of mine help, actually I helped him do it, he did most of it , mesh of gears , pinion depth, back lash , inch ft pounds on the pinion, didn't under stand really until we did it, thought I did ,
First ones the hardest, good chance to check all your other components out too,
Put my what I thought were ok, axles in a lathe and spun them up to check for straightness, horrible , we were able to fix them though pressed the stud plates straight and then skimmed up the face for wheel mounting,
What am I getting at ?,
Don't assume everything else is ok whilst your working on just the centre, I would have had maybe vibration, at the least my wheel bearings wouldn't have lasted as long as there suppose to,
Read up on what you want , traclock , sure grip, locker ?

[John_Kunkel]

To do the job correctly you'll need the aforementioned wrenches but also a dial indicator and a press to remove/install bearings.

If you don't have the needed tools or can't borrow them and if you don't plan on doing more gear work you're probably better off paying an experienced tech rather than investing in tools you may never use again.

[ws23rt]

This is very practical advice

I'm generally not one to discourage someone from doing something new. A differential is not particularly difficult but as it has been said the right tools are needed for it to be easy.

It takes very savvy and talented mechanic to do a good job with the wrong tools.

Having read up on it a bit gives you the heads up on what is needed.  Investing in a few measuring tools--(Dial indicator/ depth Micrometer ,etc) are not all that expensive and these are tool box items that you may soon wonder how you got buy without.

Pressing bearings on and off can be done by taking them to a shop with the right equipment.   Call it a learning adventure.

[femtnmax]

Good comments by everyone, and yes you need some special tools.  FYI a magnetic base dial indicator can be used on many automotive repairs/builds, so not a waste of money.
I did a ring pinion gear change using a '742' gear housing that has shim packs to set pinion bearing depth & preload.  Went together well.  Runs great no noise.
One thing I would do different next time is to buy TWO pinion gear rear bearings, then sand/polish the I.D. of one bearing just enough so you can slip it on/off the pinion gear as you determine the correct shim  packs for pinion gear depth vs the ring gear.  Then your not pressing the same bearing on/off the pinion gear.
Later I changed the ring/pinion gears on a dana 44 solid front axle for 4x4 truck.  Again went together well, no noise, no issues.  An acceptable tooth pattern can have some toe/heal contact, but if you play with shim thickness enough you can dial out that variance and have a centered pattern, just takes a little more time.  My time is free.
Best of luck

[fy469rtse]

Good suggestion on the oversize bearing, mine also 742, machined up spacer out steel to do the same thing , the friend who did most of the work did this as an additional tool to add to his mopar diff tools as he said will come in handy for future diffs , he did another less than 3 weeks later, but as said above , you need the basic tools to do this correctly, dial indicators , press , torque wrenches, inch pound torque wrench,