model aa questions
 

Hey everyone. Just got a 28 aa that I'm working on
Few questions.



1. It has mechanical brakes with wood spoke wheels I know the front end is easy to update to hydraulic brakes is there any easy way to upgrade the rear or will it require a different diff of my choice?



2. The 4 banger, 3 spd trans and warfard box does anyone actually buy those anymore ir need ? Or should I scrap
Same with the wood wheels _?

Re: model aa questions
 

Can I ask what your goals are? Maybe this would help us know what would be the best advice for you.

Re: model aa questions
 

I'm updating to a newer ford 4 cylinder.

When Allstars said and done 120 hp ?

Re: model aa questions
 

What newer 4 cylinder are you going to use?

Charlie Stephens

Re: model aa questions
 

I have never seen a AA with wood spoke wheels.

Re: model aa questions
 

Canadian had wood wheels.

Re: model aa questions
 

Yes in canada we had more wood then steel . Lol
Just kidding

Re: model aa questions
 

And the other Commonwealth countries; Aus, NZ etc had wooden wheels.

Re: model aa questions
 

1. It has mechanical brakes with wood spoke wheels I know the front end is easy to update to hydraulic brakes is there any easy way to upgrade the rear or will it require a different diff of my choice?

The "ordinary" rear end of the AA truck was decidedly a "low speed" affair. Think 35mph tops. This especially so for the "worm drive" rear of the 28-29s. Borg-Warner bevel rear would have been 30-31 (and beyond) and came in two speed flavors. The "high speed" rear end of the BW AA truck was more in the order of 42-45mph with the four speed manual transmission. Many of the high speed differentials were marked with an aluminum tag.

To make the trucks more adaptable to higher speeds many "aftermarket" intermediate transmissions were offered based more or less on the Ford "dual high" layout. (Ford Dual High was actually a "dual low" as it offered "crawler" speed)

One maker of the intermediate overdrive was Ruckstell - who also made a similar unit for the Model T truck (besides a three speed conversion to replace the planetary transmission of the T) With the AA truck intermediate shaft overdrive one could achieve 60mph.

Generally there has not been a lot of experience to convert a Model AA front or rear brakes to hydraulic. As an engineer I can see how it might be done by replacing the cams with a hydraulic cylinder - but it is not a task that has been generally done. And in so doing you take on a "reversion" in brake design. And a risk on your success.

Modern brakes take advantage of several design aspects not fully appreciated in the 1930s including "self energization" and certainly for the A and AA "self adjustment."

Since you're already considering an engine replacement, it might be best to simply "borrow" the entire engine/drivetrain/brakes from a C2500 truck and use that? Most of these you'll find to be automatic transmission, but floor mounted gear shift was available for a long time on these.

Even this is fraught with some peril. My own 1995 experience with a 1990 C1500 5-speed was less than satisfactory when it began eating its own synchros at little more than 50K miles. As the Chevrolet Service Manager said "Borg-Warner (my tranny) has forgotten a lot about building transmissions." The truck got traded for a Honda Civic.

I'm thinking your questions might be better answered over at HAMB. https://www.jalopyjournal.com/forum/

Good luck though. It's always fun to see a "survivor."

Joe K

Re: model aa questions
 

Stock AA brakes STOP.Lot of square inches of surface,you can have 25 things out of whack and unless you are heavily loaded you might not know the difference.Is there a reason you want to go through the work of hydraulic brakes,or is this a solution looking for a problem?If you have been reading horror stories on facebook,turn it off,you have been filled with crap up to your ears.