I have an 85 Z and I am currently building a rear for it I have a spare 10 bolt that somebody gave me. I have a replacement posi unit and 3:58 richmond gears for it. now my problem is that when I put the bearing caps on and the spacer or washer in between the axle shafts it is just to tight, the original carrier just drops in out no problem. Are these called the carrier shims any help would be great this is my first time for a rear!

 

i think you're confused about what you have. there are no 3:58 richmond gear sets. there is no spacer between the axles unless you're calling the pin a spacer. there ae carrier shims that go between the carrier, next to the bearings and the housing. these shims are matched to the carrier and housing. as long as you don't swap aprts around use the original shims and carrier you're fine. if you swap carriers you'll need to figure out which or how much shim you need to get correct pre load, contact pattern and back lash. never seen a carrier that just dropped in and out with "no problem" i've always had to tap the shims at the very least to get them in.

 

It is the entire carrier I am swapping, and they are shims between the bearings and the housing I am concerned about.The rear originally had a powertrax locker in it and was trashed using the same shims you do have to tap them to get the carrier in the housing and I did not know if this is ok or not and the gears are stamped 3:58. Thanks for the reply and clearing up that that they are indeed shims

 

The shims should not just fall out! You should shim the carrier to the point where you need to beat the shims in to get them all in. If the shims start to deform them it is too tight. It should be as tight as you get can get it. This sets the carrier bearing preload. According to Randy's Ring & Pinion it is nearly impossible to get the carrier shimmed too tight. They have rarely seem carrier bearings fail from being too tight, but too loose is a semi-common occurance.

The factory uses a case spreader to do this, which is why they just use one big shim per side.

Make sure that you set the gears up properly! You can't just re-use the factory shims with an aftermarket gearset. You have to go through the whole setup process again.

 

That would explain why I only have only two only big shims for the carrier and they are tight like that when I try to put them in I am just starting my research on how to properly set up a rear. I do not want to pay somebody to do it because I want to learn so if it blows up its my fault. any advice or links or how to artilces would be appreciated.

thanks

 

do a search ehre, there's been a lot of threads on setting up gear sets, read your manual it should have a sectipon on it, look at bernards site he has a how to there

www.sethirdgen.org

 

Yup, call Randy's Ring & Pinion and get a copy of their gear installation book. It's pure gold.

Harbor Freight Tools should have a dial indicator/magnetic base combo for setting backlash. Get a set of calipers that read in .0001 increments. Get a lbs/in torque wrench. Those are the necessary tools. A pinion depth tool will speed things up, but isn't necessary, plus they are expensive.