The Ford Barn

Joe K · 05-15-2026, 09:51 AM

I had to back up in my mind to re-examine materials I referred to when trying to go ahead with an original 1930 Model AA stripped chassis with only 26K original miles. Used to carry a welder for a construction company, the truck/welder was only used to move to a jobsite, and then returned to the shop. Nice original chassis with original paint and all the springs and clips intact.

I had in mind to incorporate a "Warford" intermediate transmission to get the possibility of 55mph. I had the transmission - but how to adapt it to the later 30-31 AA truck?

Part of the solution involved using a special bearing retainer for the AA 4 speed tranny - which isn't used when the coupling shaft is used. Vince Falter in his Fordgarage pages discusses the 4 speed (and its failings) and outlines the rear bearing retainer/clamshell seat for the forward Universal Joint. The diamond A-4808 adaptor uses the AA-4520 clamshells directly. Both of these (rear bearing retainer/diamond reinforcement) were found which allowed me the install of the Warford Overdrive.

Check out Vince's page where he discusses the AA-7085-B (standard 4 speed bearing retainer) and the A-7085-E (car 4 speed retainer) which appear similar but the car adaptation is "thinner" to not upset the rear axle positioning.

One can note that this 4 speed "bearing retainer/adaptor" in either version has a 1/8 npt tapped hole for install of a grease zerk to grease the rear bearing of the 4 speed.

https://www.fordgarage.com/pages/aaf...edachassis.htm

So my conclusion from this is that the AA-4520 clamshells are the same as the BB-4520 clamshells, which are the same as the A-4520 clamshells. Well, except for the "unequal spacing" bolt variants.

One should also note that the transition to and from the Warford requires a special "mix & match" universal joint (10 spline on one side and 6 spline on the other) which Vince addresses as A-7090-C being the "Spicer" Universal Joint configuration (NOT the ring-universal.)

Joe K

05-15-2026, 09:51 AM	#7
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 5,018	Re: coupling shaft assembly on AA Truck with 4 speed transmission Transmission I had to back up in my mind to re-examine materials I referred to when trying to go ahead with an original 1930 Model AA stripped chassis with only 26K original miles. Used to carry a welder for a construction company, the truck/welder was only used to move to a jobsite, and then returned to the shop. Nice original chassis with original paint and all the springs and clips intact. I had in mind to incorporate a "Warford" intermediate transmission to get the possibility of 55mph. I had the transmission - but how to adapt it to the later 30-31 AA truck? Part of the solution involved using a special bearing retainer for the AA 4 speed tranny - which isn't used when the coupling shaft is used. Vince Falter in his Fordgarage pages discusses the 4 speed (and its failings) and outlines the rear bearing retainer/clamshell seat for the forward Universal Joint. The diamond A-4808 adaptor uses the AA-4520 clamshells directly. Both of these (rear bearing retainer/diamond reinforcement) were found which allowed me the install of the Warford Overdrive. Check out Vince's page where he discusses the AA-7085-B (standard 4 speed bearing retainer) and the A-7085-E (car 4 speed retainer) which appear similar but the car adaptation is "thinner" to not upset the rear axle positioning. One can note that this 4 speed "bearing retainer/adaptor" in either version has a 1/8 npt tapped hole for install of a grease zerk to grease the rear bearing of the 4 speed. https://www.fordgarage.com/pages/aaf...edachassis.htm So my conclusion from this is that the AA-4520 clamshells are the same as the BB-4520 clamshells, which are the same as the A-4520 clamshells. Well, except for the "unequal spacing" bolt variants. One should also note that the transition to and from the Warford requires a special "mix & match" universal joint (10 spline on one side and 6 spline on the other) which Vince addresses as A-7090-C being the "Spicer" Universal Joint configuration (NOT the ring-universal.) Joe K __________________ Shudda kept the horse. Last edited by Joe K; 05-15-2026 at 10:12 AM.