Carrier Bearing Preload Measurement - Corvette Forum : Corvette Forums
Go Back   Corvette Forum : Corvette Forums > General Corvette Topics > General Automotive & Shop
Register Forums Garage Garage Mark Forums Read Auto EscrowInsurance Advertise


General Automotive & Shop Non-gen specific technical discussion. Automotive tools, techniques and know-how!

Custom Image Corvettes
A&A Corvette
Corvette tuner

Corvette aftermarket products


Parts & Products
Race Ramps
Melrose Motorsports
Parts Taxi
Pfadt Racing
Madvette Motorsports
Hi-tech Custom Concepts
Corvette Garage
Corvette Parts and Accessories
Corvette Car Care Products
Corvette HID

Bob Bondurant School of High Performance Driving
Corvette driving school

Cray Wheels

Thread Tools
Old 03-29-2019, 01:47 PM   #1
Road Tripper
DC Crew
Posts: 13
Member #127666
Member since: Jul 2013

Thanks: 0
Thanked 0 Times in 0 Posts
Carrier Bearing Preload Measurement

To the C3 Corvette Readers:

After realizing that there is a deficiency in the specification for the C3 differential carrier bearing preload (CBP), I am offering the following as a first step in deriving a numerical specification for the CBP. The currently accepted way of achieving CBP is to add a 0.004" shim to each side of the carrier after shimming to be snug. The 1978 C3 factory unit repair manual does not describe the use of a differential case stretch tool, but it does state to add 0.008" shim thickness (I added 0.004" per side) to produce the correct amount of CBP. That method of shimming to be snug is very subjective and results in a wide variation of CBP results. One person's snug could be another's tight or loose. We ought to be able to do better than that. The first step is for us to understand and accept the basic physics and mathematics of determining CBP by using an inch pound (in-lb) torque measurement gage. The procedure that could be used would be to measure it directly, which is neither simple nor practical to do because of the lack of fixturing, tooling or gaging to rotate the mounted carrier alone. There is, however, an easy way to determine the CBP by measuring the pinion bearing preload (PBP) and the total preload comprised of the PBP combined with the CBP as long as the ring and pinion ratio is known. The explanation is as follows: The ring and pinion ratio has nothing to do with measuring pinion bearing preload, but it has everything to do with measuring and calculating the carrier bearing preload. The reason why is that the ratio is the only factor that can compensate for the torque multiplication of the ring and pinion gears. In my 3.73 ratio case, when the pinion gear is rotated 3.73 times, the ring gear rotates 1.00 time. That fact represents the torque multiplication for that particular gear set. Knowledge of that ratio allows the calculation of carrier bearing preload after measuring pinion bearing preload and the combined pinion and carrier bearing preload. The correct formula to calculate only the carrier bearing preload is:

Carrier Bearing Preload = (total preload - pinion bearing preload) x the differential ratio. For example (24 in-lbs - 21 in-lbs) x 3.73 = 11.2 inch-pounds.

I am waiting for a response from the GM Heritage Center for their opinion of using the measured CBP instead of the judgmental snug procedure. I also have fabricated a differential case stretching tool that will be used to determine the CBP as a function of case stretch, and also to determine the CBP when using the currently used method of hammering the shim packs in. I will publish the results when available.

Last edited by Road Tripper; 04-06-2019 at 02:42 PM. Reason: To correct an error and to add information
Road Tripper is offline   Reply w/quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Corvette Forum : Corvette Forums forums, you must first register.
Please enter your desired user name (12 CHARACTERS MAXIMUM), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
City / State / Country?
Where you live
What kind of Corvette(s) do you own?
This field is not required.
Please select your insurance company (Optional)


Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Car carrier followed to my dealership digo C6 Corvette Z06 7 10-09-2005 04:20 PM
Carrier Pitstop matchframe Stingray's "Bad Shark" Lounge 8 06-16-2005 01:34 PM
Best handling Carrier in the Fleet! matchframe Stingray's "Bad Shark" Lounge 18 02-18-2004 01:40 PM
C6 Carrier Commercial Longtimer C6 Corvette 7 12-21-2003 12:24 AM
Bike carrier for a C4 BubbleHead C4 Corvette 13 12-10-2003 10:08 PM

Powered by vBadvanced CMPS v3.2.2

All times are GMT -6. The time now is 06:13 PM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
2003-2011, - All Rights Reserved