Worm Drive Rear Drive

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
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Don Elson
Posts: 8
Joined: April 7th, 2003, 2:13 pm
Model Year: 1930
Location: Blacksburg, VA

Worm Drive Rear Drive

Post by Don Elson »

:?: Is there any specific adjustments for the worm drive rear end? I can not find any information in the books that I have. I have changed gearing from the low speed to the high speed gearing.
Don
Buckwheat
Posts: 13
Joined: March 5th, 2003, 7:06 am
Model Year: 1930
Location: North Louisiana

Post by Buckwheat »

I have some books and information I can pour over. Is there a particular adjustment or tolerance you are asking about. I would like to learn more about your gearing change please email me at the address below.

Buckwheat
Don Elson
Posts: 8
Joined: April 7th, 2003, 2:13 pm
Model Year: 1930
Location: Blacksburg, VA

Worm Drive

Post by Don Elson »

Buckwheat: I tried to send this message to your email, but it did not go thru.

In Schild's Shop Manual and Andrew's Mechanics Handbook both tell to check bearing preload, backlash and axle end play for the bevel gear rear end but nothing about the worm gear rear end. Do these checks apply to the worm gear unit?


Don
Buckwheat
Posts: 13
Joined: March 5th, 2003, 7:06 am
Model Year: 1930
Location: North Louisiana

Post by Buckwheat »

Don,

I haven't found anything specific to the worm drive rear end yet, but I'm going on the assumption that if you adjust the Axle end play and other adjustments for a bevel gear drive - you will back into a well adjusted wormdrive.

In other words, the sum of the parts will equal the whole. Does that make sense?

As for as I can tell the worm gear and bevel gear do the same job, both turn the ring gear and things are pretty much the same after that.

We kinda sound like the blind leading the blind here, maybe someone can jump in and help us out. I have a tendency to approach these things logically and experience has shown that is not always the best method....

Buckwheat
User avatar
HKDude
Posts: 66
Joined: January 17th, 2003, 7:46 pm
Body Type: Platform
Model Year: 1929
Location: Decatur, Illinois

Post by HKDude »

I've been working on rebuilding the worm rear axle and have a modern part number to add:

AA-4221 (axle housing bearing) --> Timken p/n 39236
AA-9406 (thrust ball bearing) --> ??
AA-???? (roller bearing) --> ??

The local bearing dealer I went to was unable to find modern roller bearings or a replacement for the Gurney thrust ball bearing.

I have not figured out a process to adjust the pinion bearing (p 413 - Ford Service Manual) for this axle. Right now I have the drive shaft and tube off and the whole worm gear slides out towards housing cap when turning the rear end. I may need to install the drive shaft / tube to properly adjust it. I'm not ready to do that yet as I don't have the axle seals or gasket kit (both Snyders and Brattons are back ordered).

-mike
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