Worm Drive Gear Ratio

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
Post Reply
Bob F
Posts: 31
Joined: June 29th, 2008, 5:08 am
Body Type: 82A Platform
Model Year: 1928
Location: N E Illinois

Worm Drive Gear Ratio

Post by Bob F » March 9th, 2019, 2:05 pm

I have a 28 Worm Drive Rear End without emergency brakes, the A or B stamping is unreadable. I jacked up one wheel,and turned the drive shaft a little more than 2 and a half turns, the wheel made 1 complete turn, now do I multiply that by 2 to get my ratio?
Thanks for any help! Bob F

User avatar
Rumbler
Posts: 63
Joined: May 21st, 2017, 4:27 pm
Body Type: 82-A Closed Cab
Model Year: 1928
Location: Illinois

Re: Worm Drive Gear Ratio

Post by Rumbler » March 9th, 2019, 2:43 pm

Bob F-
If there is no stamping it is most likely a high speed because that was the initial offering. The stamping came when they started offering the low speed option, to identify which was which.

See the following thread on how to confirm high or low speed rear differential.

viewtopic.php?f=1&t=6294

Rumbler

Bob F
Posts: 31
Joined: June 29th, 2008, 5:08 am
Body Type: 82A Platform
Model Year: 1928
Location: N E Illinois

Re: Worm Drive Gear Ratio

Post by Bob F » March 9th, 2019, 3:22 pm

Thanks Rumbler, I just needed to confirm my finding and that posting was very helpful Now I just need to take it apart and check the condition of the worm & gear, I want to swap out my low speed in my 28.

njcar757
Posts: 77
Joined: March 4th, 2009, 4:00 pm
Body Type: closed cab
Model Year: 1929

Re: Worm Drive Gear Ratio

Post by njcar757 » March 14th, 2019, 6:14 pm

On my 29 the letter capital B is not vertical, it is laid on its side.

User avatar
elfox
Posts: 159
Joined: January 27th, 2011, 8:56 pm
Body Type: 88-A
Model Year: 1929
Location: Port Orchard, WA

Re: Worm Drive Gear Ratio

Post by elfox » March 16th, 2019, 1:22 am

Both my '29s have the stamp on its side. First is an "A" (low speed), and the second is the "B" (high speed).

Image

Image
Dave
Port Orchard, WA

Post Reply