Pictures of the Inside of a Bevel Gear Drive

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
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Rustynut
Posts: 14
Joined: October 31st, 2020, 11:06 pm
Body Type: C-Cab
Model Year: 1930
Location: Campbell, CA

Pictures of the Inside of a Bevel Gear Drive

Post by Rustynut »

Posting several pictures of a 1930 AA bevel gear drive rear end as I have it disassembled for inspection / repair.
Also a few pics of the pinion gear assembly.
Will hopefully supplement previous worm gear photos posted some time ago by "1crosscut"
Link to 1crosscut worm gear pics:
viewtopic.php?f=1&t=3844&p=20582&hilit= ... ive#p20582
Hoping these may help others in the future.
Attachments
Bevel Gear Disassembly 1.jpg
Bevel Gear Disassembly 1.jpg (163.3 KiB) Viewed 5338 times
Bevel Gear Disassembly 2.jpg
Bevel Gear Disassembly 2.jpg (142.09 KiB) Viewed 5338 times
Bevel Gear Assembly 1.jpg
Bevel Gear Assembly 1.jpg (280.58 KiB) Viewed 5338 times
Bevel Gear Assembly 2.jpg
Bevel Gear Assembly 2.jpg (288.56 KiB) Viewed 5338 times
Bevel Gear Assembly 3.jpg
Bevel Gear Assembly 3.jpg (219.22 KiB) Viewed 5338 times
Rustynut
Posts: 14
Joined: October 31st, 2020, 11:06 pm
Body Type: C-Cab
Model Year: 1930
Location: Campbell, CA

Re: Pictures of the Inside of a Bevel Gear Drive

Post by Rustynut »

Added pic of pinion gear assembly
Attachments
Pinion Gear Assembly.jpg
Pinion Gear Assembly.jpg (119.95 KiB) Viewed 5337 times
BERLIN FORD AA
Posts: 4
Joined: February 25th, 2019, 8:51 am
Body Type: Short Bed
Model Year: 1931

Re: Pictures of the Inside of a Bevel Gear Drive

Post by BERLIN FORD AA »

Thanks for taking the time to post this set of photos.
David R.
Posts: 260
Joined: August 17th, 2019, 1:52 pm
Body Type: Chassis
Model Year: 1930
Location: WV

Re: Pictures of the Inside of a Bevel Gear Drive

Post by David R. »

Thanks a bunch!! This is my next project. I have a spare 6.6 slow gear axle. My truck has a 5.14. The 6.6 is from lower mileage truck. I might end up swapping gear sets? What condition did you find yours in? I hear these axles were pretty bulletproof. Parts available?
Rustynut
Posts: 14
Joined: October 31st, 2020, 11:06 pm
Body Type: C-Cab
Model Year: 1930
Location: Campbell, CA

Re: Pictures of the Inside of a Bevel Gear Drive

Post by Rustynut »

My truck has the 6.6, it was in reasonable shape when I pulled it apart, very little pitting and no chipped gears.
The pinion race though had a big chip out of it and was cracked from one side to the other, so re-affirmed you really need to pull everything apart and inspect/replace as necessary (everything felt tight and rotated smoothly, so considered not disassembling - glad now I took it apart and now know its in good shape). The race was a little hard to find but a fellow Model A club member had the part from a parts AA truck, you can typically find NOS or used parts in good condition. If its specific to the AA, it may not be reproduced as not much demand...
As for higher speed, I found a 5.14 ratio one but it turned out to have several issues (spider gears wouldn't seat properly, housing slightly distorted so the two halves wouldn't mesh together properly & fair amount of pitting on several gear teeth), so stayed with the original 6.6.
So I'm going with the 6.6 ratio rear end with a Mitchell overdrive instead, which should get me to ~ 45-50MPH when necessary (don't think I want to go any faster than that in a C-Cab anyway :D
Good luck with your project!
David R.
Posts: 260
Joined: August 17th, 2019, 1:52 pm
Body Type: Chassis
Model Year: 1930
Location: WV

Re: Pictures of the Inside of a Bevel Gear Drive

Post by David R. »

Will your Mitchell replace coupling shaft? Are prices for the Mitchell for a AA comparable to those for an A? I’m interested.
Rustynut
Posts: 14
Joined: October 31st, 2020, 11:06 pm
Body Type: C-Cab
Model Year: 1930
Location: Campbell, CA

Re: Pictures of the Inside of a Bevel Gear Drive

Post by Rustynut »

The Michell replaces the torque tube / main drive shaft, similar to the Model A car installation.
There are a number of articles and youtube videos that show the typical installation for cars.
The cost appears to be about the same as the car (same internal gearing, you can get either 26% or 36% overdrive) - I believe the main differences are in the length of the drive shaft and the shaft connection ends, and the speedometer gear ratio. Delivery is taking about 100 days for the truck as they build to order. Mine should be ready this week...
Check out their WEB site & give them a call, they have always been helpful in answering my questions.
https://mitchelloverdrives.com/
David R.
Posts: 260
Joined: August 17th, 2019, 1:52 pm
Body Type: Chassis
Model Year: 1930
Location: WV

Re: Pictures of the Inside of a Bevel Gear Drive

Post by David R. »

I was hoping they made one that replaced coupling shaft like the Warford. I think I will see how it goes driving stock with high speed gears before I take the leap. I’ve been nearly a year trying to get engine done. I have some rusted rivets to replace in frame then I will start on rear end.
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