Hello,

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

You can't assume that the parting line is in the center of the carrier bearing.
You can take measurements of the bearing caps and the opposite bearing cavity and determine if the parting line is centered or not. You will still need a depth micrometer, though.
I've never used shims between the case & the race. I've always known of them being placed between the bearing and the head of the pinion, but I don't see why it wouldn't work..
JA

Just go spend 8 or 10 buck's and buy a extra inner pinion brg and hone out the inside of the brg so it will slid on and off, No need to spend any money on pinion setting tools. Or there is shim kit's for putting the shim under the race also.

I've always wondered about putting the pinion shim behind the outer race, it sure would avoid a lot of trouble..

You can set up a differential without the depth tool, just check the contact pattern of the teeth and adjust.

Hello,

The Ratech pinion depth setting tool doesn't measure to the parting line of the carrier bearing cap, it is used to measure to the machined outer race perch.

BBP

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

"The Ratech pinion depth setting tool doesn't measure to the parting line of the carrier bearing cap, it is used to measure to the machined outer race perch."
.
Sorry, my mistake. I've never seen the tool you mentioned, and made the mistake of assuming it works like most pinion depth tools of the price range.
I use this tool.
JA

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Well, I finally got the depth gauge (UPS), it's actually a vernier caliper with a small tail that sticks out the end. You have to be very careful when taking the depth readings, keeping tool straight up & down, with its flat end flat against the top of the Ratech tool.

The tip is .050" wide & I'm trying to measure to a curved 3.000" diameter carrier bearing perch, so I did a little trigonometry & calculated that the tool would measure about .0005" too short, (not much).

My average reading was .514" down to the center of the carrier bearing perch. The Ratech tool has 3.316" stamped on it. (3.316 - .514 = 2.802)

The Richmond pinion has a checking distance of 2.791" on it, (2.791 -2.802 = -.011") so my pinion head is about .011" too close to the centerline of the ring gear & the carrier bearings.

As my garage is cold, I heated up the "pumpkin" housing to about 85* with a torch & heat light on inside. I did this to get the bearings & grease up to a more normal temperature & viscosity.

I shimmed the solid spacer that replaces the crush sleeve & got the pinion pre-load set to about 25 inch pounds. I did this using a wood stick as a lever & a 2.5# weight. At about 10" of leverage horizontal, the weight would just rotate the pinion (2.5 x 10 = 25) When turning the yoke flange by hand this feels pretty tight.

I installed the grease seal. Used blue permatex "make a gasket" on the outside surface where it goes into the housing, put a little grease on the black flexible lip & tapped it in. I left it about 1/8" out as I have read that if you seat them all the way that 12 bolts tend to leak for some reason. I put the blue permatex on the splines, slid the yoke on & put red locktite on the threads & torqued the nut to 150ftlbs.

The large pinion bearing is stuck on the pinion with a .025" shim & I don't have a bearing puller available (I live in a very remote area in the mountains of S. Colorado).

Sooo, I decided to install the carrier & use the marking paste to see how the gear marks look. They actually look pretty darn good, drive side is a little close to the toe as I expected (inside of ring gear) This is suppose to stronger as the pinion is deeper into the ring & upon hard acceleration the pinion will try & walk toward the middle of the teeth. Coast side looks good & even. The ends are pretty oval & evenly spaced between the top (face) & the root (flank). I love the esoteric terminology, he he.

I am waiting on a new digital camera to come from Amazon. I will post pics. here ASAP. I'm still adding shims to the carrier bearings & measuring backlash. It's getting really hard to slide any more thin shims in???

BBP

Your carrier brgs need to be preloaded also,and your carrier should NOT just slide in and out. You should have to work it a little to get the case out.If your preload is off the brgs will spin in the housing and bad things will happen.

If I start from scratch on a 12 bolt bolt I always start with .038 under the pinion and that will usually be in the ball park.

Dont do anymore changes on the pinion till you have your backlash set WITH the correct preload on the carrier brgs.

When your carrier is in the housing,and if you can just grab the carrier by hand and pull it out, Te preload is too loose!!!

For the carrier preload I like to put in the carrier with the shims on one side of it, then hammer in the shims on the other side using a 1/2" diameter steel rod as a sort of drift.

Read this link, it is pretty comprehensive:
http://www.yukongear.com/Downloads/...nstructions.pdf

For the pattern I would focus on having no hard straight line in the pattern along the tip or the root.

Thanks for the advice & that link, very good info.

I checked my backlash & it was about .012"

I needed to reduce the backlash & also needed more carrier bearing pre-load.

I was able to jam a couple of screwdrivers between the housing and the ring side of the carrier, I pounded them down to create considerable pressure across to the shim stack on the other side.

I was able to remove the entire ring side shim stack as a unit, I added .007" in the middle, the 2 outer are quite thick. I put some WD40 on the outside & was barely able to pound the entire shim stack back in using my brass drift.

Backlash now is about .009" & carrier bearing pre-load is tight. It now takes about 30 inch pounds to turn the pinion. I don't know how much the grease seal or the cold temp. 50* added.
Ideal should be: My pinion bearing pre-load of 25 + (25 x (1 / 4.56)) = aprox. 30.5 inch pounds.

I checked the engagement pattern with the marking paste & it looks even better. Both sides are fairly centered up & down. Drive side is a little closer to the toe, & looks long & with rounded ends.

I think it's set up pretty good. Thanks again.

BBP