Setting ring & pinion, chevy 12 bolt

[Buffalobillpatrick]

Hello, new guy here (really old retired guy) 1st post.

This is kind-of a build along & question along thread. I have never done this (successfully) before.

I'm setting up 1972 Chevy passenger 12 bolt rear-end, (8.875" ring & pinion).

I picked up "pumpkin" at a bone yard & cleaned it out completely, looks good.

all other parts are new.

I have a Richmond 456 ring & pinion, Moroso Posi, Strange axles that are C-clip eliminator type, Timken bearings.

I welded the tubes into the center section & cut off the tubes just past the 4 bolt flanges, this is required for the Strange axles. Tapped the 1/8" NPT vent hole & Re-cleaned everything.

I'm trying to setup the pinion depth to 2.791" Richmond calls it the "checking distance" (this is the distance between the flat circle of pinion head to the centerline of the carrier bearings)
Also setting the pinion new bearing pre-load (25-30 inch-pounds)

The large pinion bearing inner race was a very tight fit to the pinion shaft, so (not being the sharpest knife in the drawer) I greased the race & shaft, put in a .025" shim between the pinion head & the inner bearing race & pounded it on with a brass drift, avoiding any contact with the bearings. (I have no press) Then heated up pinion shaft with a torch & re-pounded the race to make sure it was on all the way, (it's in & it's stuck).

Later when dealing with the small pinion bearing inner race, I found that I could easily reduce the pinion shaft by putting pinion in my bench vice & "shoe-shine" it with a 1" wide x 18" long strip of emory cloth stuff that I use for cleaning copper pipes, 1 minute tops. (I wish I had thought of this before I beat the large bearing on)

I got a Ratech pinion depth setting tool,
http://store.summitracing.com/partd...15&autoview=sku

Has anyone else used this? I hope it will be accurate.

Now I'm waiting on a depth micrometer from Amazon to put through the hole in the above tool to measure down to where the carrier bearing outer race will sit.

I also bought a Ratech solid spacer kit 1901,
http://store.summitracing.com/partd...15&autoview=sku

This takes the place of the normal crush sleeve & 6' breaker bar method (GM's revenge, oops I went too far method, he he).

This solid spacer & shims are used to set the distance between the pinion large & small bearings, which sets the pinion bearing pre-load (new 25-30 inch-pounds)

This kit provided shims that go between the "pumpkin" housing and the large pinion bearing race. I can easily, (with a brass drift), beat the large pinion race out of the housing from the front end as there are reliefs machined in the housing for this purpose.

Has anyone else used this kit or put shims between the housing & the large bearing race?

To be continued:

BBP

[ls1 nova]

Personally I would not reduce the pinion shaft diameter. The bearings are pressed on so they do not "spin" on the shaft. By reducing the pinion diameter you are prone to wearing either the bearing or the shaft. I would also be hesitant about heating the pinion with a torch(to much heat). When installing bearings I would not want the temp to go much above 300-350 degrees. I use a bearing heater but have had good results with a toaster oven believe it or not. Just takes a little while.

Also your inch pound rating is a rotating torque, not an overall torque. The pinion nut needs tightened to the apropriate ft/lb. The spacer is there to set the pre-load wich is your rotating torque.

If you are going with a pinion depth gauge invest in a Mark Williams gauge. I have seen the summit gauge and am not impressed. I do own the Mark Williams gage and it is of the highest quality.

I am not saying your method won't work but I feel it is questionable? Just my .02

[Buffalobillpatrick]

I may have heated the pinion shaft up to 180* & maybe removed .001" in the area of the small bearing race, pretty darn evenly all the way around, just some of the black surface. I don't think that I ruined it (I hope). I will find out down the road.

The small pinion bearing race is not loose & will not rotate. The solid spacer & shims that I'm using to set the pinion pre-load will clamp it to the large bearing inner race, which is really stuck.

I understand how to set the pinion pre-load to 25-30 inch pounds. It is a challenge though, due to my cold garage & grease getting thicker. For my final testing, I will heat up the carrier. I have an IR gun that gives an instant temp. readings.

Click on the 1st link in my 1st post for a picture of the tool. I have several references by guys who use it & like it. It does not bolt on, you firmly press it flush on the head of the pinion gear, there is a nylon centering button. The end of it goes over against the carrier bearing race perch to set rotational position & then you put a depth micrometer straight down through the 1/4" hole & measure to the bottom center of the bearing race perch. Then subtract result from the number stamped on the tool. My Richmond gear set has a "checking distance" = 2.791"

Pinion nut will get 125 ftlbs & red locktite, splines will get blue permatex, as will the outside of grease seal.

BBP