Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 03-11-2019, 09:52 PM   #1
Paul Bjarnason
Senior Member
 
Join Date: Jul 2018
Location: Annandale, VA
Posts: 113
Default backlash

I rebuilt the rear end of my '29 Tudor found upon assembly that the drive shaft will only turn with "fits and starts", like clanking. I measured the backlash as well as I could and determined it is at least .040. I think the herky jerky on turning the is due to too much pre-load, although I assure you that I used a torque wrench when I set it, to 20 inch pounds. I think I can back off on the pre-load but I am not sure what to do about the backlash which is excessive. To obtain the correct pre-load on the axles I have .012 on the left and .005 on the right in gaskets. Moving gaskets from the right to the left side will reduce the backlash. The minimum gasket size available is .003- so, I can move .009 from the left side to the right side and then see where I am. I have ordered some .005 carrier shims, but I cannot see where using those will help reduce the backlash, since I am already at close to the minimum on the right side. Putting a shim on the right side will increase backlash. Putting one on the left will not accomplish anything that adding thicker banjo gaskets won't. Any ideas out there? Thanks in advance.
Paul Bjarnason is offline   Reply With Quote
Old 03-11-2019, 10:24 PM   #2
jetmek
Senior Member
 
Join Date: May 2010
Location: albany
Posts: 306
Default Re: backlash

need more info....new or used ring and pinion? where are you measuring backlash? you need to assemble and set up the carrier preload first without the pinion installed. once you have that with equal gaskets on each side install the pinion and tighten both nuts...sometimes tightening the lock nut will make the bearing preload too tight and give you a ratcheting feel like you seem to have. adjust so it turns smoothly. assemble the center and check backlash at the pinion you want about .006. adjusts gaskets from side to side accordingly. If its too much you need to get arbor shims to bring the pinion in closer to the ringgear. or replace excessively worn gear set. trial and error ...
__________________
engine and component overhauls my specialty!
Website- www.godevilgarage.com
jetmek is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 03-12-2019, 11:01 AM   #3
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 6,359
Default Re: backlash

Have you read Tom Endy's articles? Go to the link and scroll down to differential.
https://www.santaanitaas.org/tom-endys-tech-articles/


Bob
Bob C is offline   Reply With Quote
Old 03-12-2019, 11:23 AM   #4
Jim Brierley
Senior Member
 
Join Date: Jun 2010
Location: Temecula, CA
Posts: 2,845
Default Re: backlash

You may need to shim under the right bearing race to move the ring gear to the, right. OR maybe move the pinion farther in towards the ring gear to accomplish the same thing. Moving the pinion in is easier and may accomplish what you need. You definitely have too much backlash. These diffs aren't rocket science, so not overly particular.
Jim Brierley is offline   Reply With Quote
Old 03-12-2019, 05:24 PM   #5
Paul Bjarnason
Senior Member
 
Join Date: Jul 2018
Location: Annandale, VA
Posts: 113
Default Re: backlash

Quote:
Originally Posted by jetmek View Post
need more info....new or used ring and pinion? where are you measuring backlash? you need to assemble and set up the carrier preload first without the pinion installed. once you have that with equal gaskets on each side install the pinion and tighten both nuts...sometimes tightening the lock nut will make the bearing preload too tight and give you a ratcheting feel like you seem to have. adjust so it turns smoothly. assemble the center and check backlash at the pinion you want about .006. adjusts gaskets from side to side accordingly. If its too much you need to get arbor shims to bring the pinion in closer to the ringgear. or replace excessively worn gear set. trial and error ...
Yes, you're right about the pre-load, as the ratcheting went away when I backed off on the pre-load. Funny thing was that I set it with a torque wrench and the axles were out. I was unaware of "arbor shims" to move the pinion in, and I will try that if I cannot get the backlash down by using a .003 gasket alone on the right side. Thanks.
Paul Bjarnason is offline   Reply With Quote
Old 03-12-2019, 08:45 PM   #6
redmodelt
Senior Member
 
redmodelt's Avatar
 
Join Date: May 2010
Location: Portland OR
Posts: 4,463
Default Re: backlash

Shims will only move the pinion out from the gear not closer. You need shims under the cups or bearings on carrier or in axle tubes. Then you need to reset everything.
__________________
I know the voices aren't real but damn they have some good ideas!
redmodelt is offline   Reply With Quote
Old 03-12-2019, 09:01 PM   #7
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 6,359
Default Re: backlash

If he puts a shim on the pinion and them the bearing that should move it
in towards the carrier but I don't think that is the correct way to do it. Need to
move the carrier over.


Bob
Bob C is offline   Reply With Quote
Old 03-12-2019, 09:26 PM   #8
Paul Bjarnason
Senior Member
 
Join Date: Jul 2018
Location: Annandale, VA
Posts: 113
Default Re: backlash

Quote:
Originally Posted by Bob C View Post
If he puts a shim on the pinion and them the bearing that should move it
in towards the carrier but I don't think that is the correct way to do it. Need to
move the carrier over.


Bob
The only way to move the carrier closer to the pinion is to move gaskets from the left side to the right side (assuming a correct axle bearing pre-load, which is the case). I will do that Thursday and report back.
Paul Bjarnason is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 07:31 AM.