1969 axle bearing spacing - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 01-30-2016, 07:50 PM Thread Starter
 
Boss_hoss's Avatar
 
Join Date: Jan 2016
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
1969 axle bearing spacing

I'm working on a 69 custom S and I rant into a snag when replacing the rear axle bearings. I purchased new axle shafts and new bearings while I'm installing rear disc brakes on my car. I didn't take a measurement when pressed off the old bearings off so when I pressed the new bearings on the new axle shafts I pressed them on as far as they would go which in looking at it now was probably wrong. When I bolt the retainer plate to the axle housing then try and assemble the brakes the new rotor hits the caliper bracket. Does any body know what the stock distance from the outer axle bearing is to axle flange?
Boss_hoss is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old 01-30-2016, 08:43 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,655
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 390 Post(s)
Garage
I don't think you need that measurement. Pressing the bearing on all the way is correct, you don't want to try and space it in or out if that is what you are asking. The bearing should be flush with the axle tube so you bolt the retainer on to keep it in place.

Double check your brake installation to make sure you have it right. Are the brackets left & right and you have them flipped? Can't you shim the bracket out if needed (I read some kits come wih shims or do require them to get things to fit)? You might want to contact the manufacturer of the kit and they may know exactly what the problem is and how to fix.

I would also measure the new axle against the old axle to make sure there is no difference in the distance from the back of the axle flange (where your rotor goes) to the bearing. It is possible it was machined deeper or the flange is narrower? But most likely both axles are the same.
PontiacJim is offline  
post #3 of 6 (permalink) Old 01-31-2016, 07:18 PM Thread Starter
 
Boss_hoss's Avatar
 
Join Date: Jan 2016
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
That's what I thought too. I got new Yukon axles which are the correct length but when I seat the axles and go to bolt on the retainer plate the bearings are not fully in the axle housing. It looks like the if the bearing were inboard 1/4 inch the bearing would be fully in the housing and retainer plate and disc conversion bracket would in in the right locations as well. Anybody else have thoughts.
Boss_hoss is offline  
 
post #4 of 6 (permalink) Old 02-01-2016, 06:52 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,655
Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 390 Post(s)
Garage
Quote:
Originally Posted by Boss_hoss View Post
That's what I thought too. I got new Yukon axles which are the correct length but when I seat the axles and go to bolt on the retainer plate the bearings are not fully in the axle housing. It looks like the if the bearing were inboard 1/4 inch the bearing would be fully in the housing and retainer plate and disc conversion bracket would in in the right locations as well. Anybody else have thoughts.

Sounds like a wrong bearing. Buy a cheap caliper ( Test, Measurement & Inspection | Calipers | General Tools Fraction+™ Digital Fractional Caliper, 6" (150mm) | 501225 - GlobalIndustrial.com ) like this one. As you open the jaws, the metal slide rod will extend out. You can use this to measure the depth of your axle tube from the edge/flange to the inside shoulder of the tube where the bearing seats. Once you know the depth, lock it in using the thumb screw, then use the caliper jaws to see if they will fit over the bearing. If not, your bearing is the wrong one as it is too wide. If it is the same, then it should work and you need to simply tighten up on the 4 bolts that hold the retainer and draw it in. Make sure the tube is clean and no debris is causing it not to stick.

Do you know that the rear end is original and has not been replaced?

Also, post a photo as that might help us.
PontiacJim is offline  
post #5 of 6 (permalink) Old 02-03-2016, 10:07 AM
 
Join Date: Jan 2015
Location: Injun Territory, 'Merica!
Posts: 1,611
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 121 Post(s)
Quote:
Originally Posted by Boss_hoss View Post
I'm working on a 69 custom S and I rant into a snag when replacing the rear axle bearings. I purchased new axle shafts and new bearings while I'm installing rear disc brakes on my car. I didn't take a measurement when pressed off the old bearings off so when I pressed the new bearings on the new axle shafts I pressed them on as far as they would go which in looking at it now was probably wrong. When I bolt the retainer plate to the axle housing then try and assemble the brakes the new rotor hits the caliper bracket. Does any body know what the stock distance from the outer axle bearing is to axle flange?
Will be out tomorrow and measure a stock axle. Your '69 Custom S, the axle uses a sealed axle being with the internal seal up in the axle housing? That is the most common axle in a '69. I've only ran across a few tapered bearing axle '69 Pontiacs, and they were all late season '69 Firebirds.

Bearing wise, the RW507C axle bearing was used from '64-69, the RW507C is the same OD and same internal diameter as its successor, the tapered axle bearing A9. The axles for an A9 bearing are machined slightly different and have a smooth surface right outboard of the step in the axle so the external seal (National 712146) will have a smooth area to ride on.

typical aftermarket rear disc brake kits require spacing the caliper bracket out some from the r/e housing flange, this is so the loaded caliper will line up with the rotor. Most such kits are made for cclip rearends like the Chebby 10 bolt or 12 bolt.

When installing on bolt-in axle rearends, the caliper mounting plate must have a bore large enough, so that a custom spacer that butts up against the axle bearing or axle bearing/external seal and extends out through the thickness of the caliper bracket, then the axle retainer clamps up against this spacer. The spacer limits axle movement in and out, and allows for the bolt in axle to be slid out of the assembled rearend with rear caliper brackets mounted intact on the rearend housing.

First adapted '79-81 T/A rear discs on a 12 bolt Chevelle, a '69 Firebird housing and several 8.5 Abody rears in the '90's. Over the last 10 years, have pulled and sold numerous S10 rear disc pieces to adapt onto cclip and bolt in axle 8.5 rears. Either style of rear disc brackets and calipers used in a swap presents a few challenges and will often require a certain size spacer.

Budget (chinese) axles...would really help to have the dimensions of the replacement axles you have. Whatever set-up you are using, the axle bearing should have indeed be fully seated on the axle.
Pinion head is offline  
post #6 of 6 (permalink) Old 02-08-2016, 10:32 PM Thread Starter
 
Boss_hoss's Avatar
 
Join Date: Jan 2016
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
So here's the scoop. After doing a little measuring I've discovered the following. The Yukon Gear and Axle shafts I purchased are the same overall lengthens the original HOWEVER. The lip on the flange that the bearing is pressed up against is milled down 3/16 over the stock flange. This accounts for the bearing not fully seating in the axle tube and the interference with the disc brake brackets. Since this is a replacement part that is designed to work on all BOP rear ends from 65-73 I suspect it is milled down a little more to accommodate all variations in bearings, seals etc. My only solution at this point is to move the bearing in 3/16 on the axle shaft and that should fix the problem. I may contact Yukon to make sure this is not an anomaly, I'll let you know.
Boss_hoss is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, Lemans & GTO General Discussion

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear Axle Bearing Replacement kenbaustin 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions. 1 04-06-2013 09:44 AM
Differential Pinion bearing and driveshaft bearing support (05 GTO) bonso Drive train, suspension, alignment and brakes. 9 06-04-2012 09:32 AM
64 Axle Bearing Replacement Al T 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 18 05-10-2012 04:57 PM
Rear Axle Bearing Retainer help GTO Fanatic 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions. 4 03-22-2011 07:02 PM
1969 gto special order axle ratio ??????? D1147 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 6 08-02-2010 04:21 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome