I was needing 4.56 gears put in the rearend. When I bought the Jeep the guy had already had them put in the front but not in the rear I have the gears and everything to put them in with and was needing to know how hard it was to install? Or if anybody knows of a good shop around Louisville KY

 

I take it they never used 4wd? Gears have to match front and rear or itll cause problems in 4wd.

 

The guy had it parked for a long time he was fixing it up and never got around to putting the gears in the rear.

 

you need some specialty tools (dial indicator and setup bearings are nice to have). its not necessarily hard, but just need to do some reading beforehand to understand the concept. if done wrong, it doesnt end well.

 

It's precision work. You can't just slap them in and call it good. You have to put it together and take some measurements, take it all apart, adjust, put it back together, measure, take it apart, adjust...

The bearings are usually press-fit. So getting things apart and back together involves either pressing/pulling bearings (which risks damaging them) or buying some setup bearings that have been machined to be able to slip on and off easily. You use them to get the shim packs figured out and then press on the actual bearings as a last step.

I've done gears in two of my Jeeps. But I have the tools and the patience to do the job.

Just about everyone just goes to a local shop to get the work done. It's worth the several hundred dollars to have someone else do it.

 

OP,people have been doing it working off the floor in their garage since cars were invented.

Generally you'll install the R&P three times...

First one will be w/ the OEM shim, second will be a large adjustment(approx. .010 to .020) unless your OEM shim is good, which is rare. And finally based on those two patterns you should be able to zero in on the correct shim size.

Buying set-up bearings is not necessary, get yourself a cheap set of pinion bearings and use a die grinder and a round stone to open the I.D. of the bearing up until it fits over the pinion.

Really not that hard to do, it does take some patience. If your working on a 8.25 it's even easier.

You will need a dial indicator with a magnetic base.

Post up some pictures of your pattern, that's always a good read.

 

Yea it's a 8.25 was thinking about just getting another one from a junk yard to practice on I've called a few shops and they want any where between 900 to 1800 to do the work

 

Wow, that's a lot of money to do that job.

A bearing race driver kit will make the job easier too. You'll actually only need to purchase the large pinion bearing to make your set up bearings, you can re-use the existing small pinion bearing for that purpose.

The only other problems I see are the gear will need to be clearance for the cross pin, and depending on what kind of R&P you get the ring gear may need to be heated to get it on the carrier. Sometimes they drop on, sometimes not.

I don't think you'll need to practice on a JY axle. Get a Install kit from Yukon, they will give you a great installation manual that will answer questions that come up.

 

Why would you need to clearance the gear for the cross pin ??

That's not a normal thing......unless you are the extremes of the gear ratios.

Is that such a common thing ?


.

 

a c8.25 has adjusters no shims and i doubt the bearings will just drop on if it does you probabably have the wrong size beariing. if you want to save some dough you should do it yourself and take your time it takes a few tries if its your first time you will need an adjuster tool, dial indicator, gear marking compound, torque wrench with some extentions to fit through the long ends of the axle tube, dremel cut off wheel to remove bearings, this is just to replace the bearings i cant comment on new gears i believe they wear in and you need to readjust after so many miles.


marc


edit: correct myself the carrier doesnt have shims adjusters only

 

this video helped me out quite a bit but i only had to replace the bearings


marc

 

How exactly did the "the guy" install a gear set in the front differential? Can you be sure it was set up properly? If not, it won't last very long. A properly installed gear set will be trouble free for perhaps tens of thousands of miles but a hack job could burn up and leave you stranded in 50.

 

4.56 is getting up there, won't be as much grinding as a 4.88 but it will need to be done if using the original differential carrier.

The shims that are being referred to are the pinion shims.

 

Ok...I had to do it on a set of 4.56's in a chrysler 9 1/4, but wasn't sure if it was the same on other axles too for the higher ratios

 

Differential setup isn't "hard", but it's something that can take a lot of time, and be frustrating at times.

On axles like a 14 Bolt, setting up the axle is easy since there are no carrier bearing shims, just adjusters. In addition, the pinion is a bolt in deal, which makes removing/adding shims quick and easy. The 9" is very similar in being nice and easy to setup (since the entire assembly is it's own chunk).

I'd say $300ish is what should be expected to have someone setup a gearset. If you are at all contemplating a locker, now would be the time to do it (unless it's a lunchbox locker). A full case locker will require a full re-do.

Investing in the tools necessary isn't cheap, but if you ever plan on doing it again, you'll pay for them with a second setup. Off the top of my head:

- Clamshell braing puller or setup bearing. It needs to be noted that setup bearing will not mimic actual pressed on bearings the exact same. Shimming will be required to make up for the difference.

- Dial indicator and magnetic base

- Torque Wrenches
1.) 1 Capable of 20-100 ft-lb. or so
2.) 1 Capable of 100 to 300 ft. lb. or so
3.) 1 Capable of 0 - 100 in-lbs

- Extra Pinion nuts (most pinion nuts once removed, are not reusable, and should not be reused)

- Calipers for measuring shims

There's a couple other smaller tools that I'm probably forgetting.

As far as the front setup...trust but verify since it's never really been run.

I'd at least check the backlash run out on the front, as well and mark the gears and see what the pattern looks like.