I have a 91 Z28 and im tired of the cheezy 2.73 gears so i plan on installing 3.73. I dont know much at all about the rear end, how do i find out what carrier i have. I did find out what size rear end i have its a 7.5 with a 28 spline. What is needed to install the gears after i buy them. all i want to install is the ring and pinion gear. Ive been told that i dont need the shim kit if that all im installing.

 

there is a kit form summit i dont know the exact part# but it includes shims and baerings. u might not even need the bearing but u never know untill u get in there. i reaplaced my 2:73's with 4:10 in my 94 and the only shims i used were the ones that were is the housing and all m bearing were still good. i would reccommend replacing the axel seals.

 

The 2.73 is a "2 series" carrier.

I just noticed Summit's their website is a little less helpful thna the print catalog. The print catalog has note "For 3.08 and numerically lower carrier" or something like that. The website is a little more technical, saying "2 series".

Anyway, hth.

 

ok so i have the series 2 carrier then thanks alot. Now im just courious. A couple of people i know have mustangs and when they changed the ring and pinion they didnt have to mess with any of the shims or anything they just changed out the gears and were on their way the only winding they get is when they let off the gas. Can i do the same thing or do i have to get the shims?

 

hate to say it but if you're asking i don't think you should be doing a gear swap on your own. you need shims, you need a few precission tools, you need some common hand tools, you need the install kit.

 

Yea i know that it sux, changing gears but i know that its completely worth putting it in and i no a couple of that would help me out with the job. Now is their any suggestions to make the job any easier?

 

You should get the service manual for your vehicle. It identifies tools and procedures required to remove and install the rear end gear including all measurements and adjustments. It is not just a matter of removing the old and installing the new. There are critical adjustments and shimming that need to be accomplished to do the job right. Having the service manual is invaluable.

 

Or, even better:

Don't try to "cheeeeep out" on the parts. Just get a gear install kit, because you're going to be needing it, period. Then find somebody you know that REALLY knows how to set up gears (like, they work at a dealer or some such), and pay them to come to your house and do it in front of you while you watch. Then you'll know what it takes and how to do it. It's almost certainly going to be cheaper in the not-so-long run if you that way, compared to buying gears and bearings 2 or 3 times until you get it right.

You can't even put the pinion in without its shims; the shim goes on the pinion before the bearing is pressed on. It's difficult to get the old bearing off of the old gear, so that you can salvage the old shim, so you can put it on your new pinion before you put the new bearing (from the kit that you will already have that will already have new shims it anyway so that you won't need the old one) onto the new pinion. You select the correct shim based on a measurement of the housing that you make using a particular special tool (pinion depth checker) which I'm guessing you don't have, don't know where to get, and don't know how to use.

I wouldn't put too much faith in what your Mustang buddies claim they can "get away with" doing. Sounds like they are creating the kind of cars you can buy all day long for bottom dollar, because everywhere you look in the car, big expensive things have been crudely hacked by one or more POs and now requre expensive and invasive repairs to render the car halfway reliable again.

 

Somebody coming to your house with an arbor press to install the pinion bearing? Never heard of that before.

Any good shop around here would laugh at you if you made a request like that.

 

You can make a small mechanical press that will be more than adequate for the job. Takes a bit longer to work with since it's not hydraulic, but it can easily be done.

You can also take the carrier to a shop and have them do it. Might be running back and forth a couple times to get the pinion depth right, but it's doable.

But like the other guys said, this is one of the jobs where if you need to ask, it shouldn't be attempted. If your backlash or pinion depth are off by .001", the gearset can be trashed in a matter of miles. A piece of paper on average is .012" thick to put that in perspective.

 

bearing seperator and puller eliminates the need for a press to get bearing off, or you can take it to a shop with a press and have it done in a few minutes for a few dollars.