Rear Gear Change?

[camino70]

When I bought my car I was told it has 3.73's in it, but the reciept I found has a PN for richmond 3.90's. I was also given the stockers with the car.

I want to swap back to the 3.42's!

I have read the stuff on gnttype.org about putting in a posi, but it doesn't say anything about the pinion. I would like to do this myself, but also don't want to have to buy new gears and have someone do it in the future (I would rather it be done right the first time).

Is this beyond a do it yourselfer? I recently pulled the motor and installed my cam, so I am somewhat mechanically inclined?

Any tips/tricks or warnings would be greatly appreciated!

Ron

 

[Chris Cornett]

It requires precision tools to properly do the install. $150 well spent to pay a pro IMO.

 

[camino70]

Thanks,
I was hoping for the opposite, but had a feeling thats the way it was going to be.

Ron

 

[sowle]

Pull the carriers pinion bolt. Rotate the carrier and pull the pinion bolt from the carrier and inspect it for wear, if there is replace it. Get yourself a magnet or needle-nose pliers and pull the c-clips and then the axles[wheels and drums have to be removed]. See if the carrier spins nice and freely[basically checking out the carrier bearings]. The carrier may take some persuasion to come out you may need a pry-bar, MAKE SURE THE SIDE SHIMS DON'T GET MIXED UP.... Once out check the bearings again for chips or wear. Get yourself an impact to take of the pinion nut, ring & pinions are matched sets. I defenetly recommend new pinion bearings and pinion seal. And buy good ones. I also recommend getting an aftermarket shim setup over the crush sleeve style if you are serious about your car.

 

[sowle]

Then tighten up your new ring gear to about 70-75 foot-pounds in a star pattern. Tap your inner and outer new pinion races into the center section with a punch-take your time.... Install the new pinion[the inner bearing will have to be tapped on also]. Do not tighten it all the way yet. Jamm your carrier in with the shims on the assumed correct side, This might be a real mother. Then tighten the bearing caps [on their correct sides]to 65. Install the rest of the equippedment momentarily-axles, pinion shaft so-on. Now you ready to set pinion bearing pre-load and contact patches. You really should invest in a shim kit for the pinion, but if you going to use the crush sleeve method you'll need a new one. A trick I like to use is spin on two lug nuts on each axle and then get two pry bars and put them through the axle studs to hold the axles for leaverage [on the ground or hoist]from spinning every thing. Now your ready to tighten the pinion nut. BY HAND! Take full turns untill you feel the pinion gear tighten up then take steps in tightening the pinion nut meanwhile keeping your eyes on the contact patch. You are going to need a two foot extension on your breaker bar. Remember that you don't want your tooth pattern exactly in the middle but just a little towards the inside of the rear end.

 

[sowle]

Once you've established this, you need to back the pinion nut off ever so slightly to set bearing pre-load. I do this by feel usually, grab ahold of the yoke and spin it and adjust it, you may want to put some lock-tite on the nut if it makes you feel better, also deffinetly the carriers pinion bolt. I prefer the blue for this. Everything else is easy, if anything needs adjustment you'll know within a few miles. Good luck. Hope this helps.

 

[camino70]

Thanks Sowle,
I am going to have to seriously think about this one