Technical Quick change onto Model A rear end

Is it practical or even possible to install a quick-change onto a stock Model A? I'm thinking of a Model A with a flathead and '39 transmission along with juice brakes but still running a stock rear. And yes, I know the rear is weak and I'd have to be careful. Or does it have to be swapped out for something '33 or later?
Sorry for what may be a stupid question but I'm stuck at home and dreaming.
Ned

 

Sure you can do it. Only weakness is an unsupported pinion, but many have been used in sprint and race cars for decades.

 

Yes, there are Model A specific quick change centers just like the ones for the V-8's.

 

remember that the '32-'34 rears were spaced closer to the housing as the springs were "bowed"...

 

The Halibrand center for a Model A and B is a model 101. The V8 model was known as a 201.

 

Kiwi Quick Change for Model A is what I have.
Check past posts and I see a FB page.

 

"Sure you can do it. Only weakness is an unsupported pinion, but many have been used in sprint and race cars for decades"

Thanks to everyone who responded. I'm unsure of what an "unsupported pinion" is? Or why the Model A rear is different than any other car. Can you explain pls. Thanks.

 

An unsupported pinion doesn't have a bearing past the gear, just bearings on the input side.

 

I would have no fear of a mild flathead running through a model A rear end on a street machine being driven with some restraint. Many of us old guys beat the living hell out of model A rear ends in our youth. I have no trouble with the stock rear end in my banger that puts out more torque than a whole lot of V8's. However I don't go crazy with it either. I would love a quick change for the cool factor but my F150 RTS has been very satisfactory.

 

My RPU has a T-5 from a S 10 4x4 keeping the torque tube to a Halibrand 101

 

It's hard to brake a rear end unless you have a tire that will stick to the Asphalt. Skinny rubber bands generally just spin. Now if you like to side step the Clutch there's a chance you could eventually brake something. That's not normally how we drive our Old Iron. I think your safe with a Model A diff.

 

I have a Halibrand 101 I'm going to use in my Model A

 

The midget quick change is based off the model A rear



There are three quick change sizes.

The Midget

The V8 or 6 spline in oval track racing

and the Champ or 10 spline in oval track racing

 

originals were made in NZ , if you check “Kiwi Quick change” on Fake Book they are now made in Balmain NSW Australia, both V8 and model A.

 

Thanks to everybody that responded. You answered all of my questions, all very clearly too.

 

...if you look at the picture of original advertising straight to the right of where it says" Downey machine company " you can see the pinion gear behind a cast in boss and a bearing on the nose of the pinion....stock model A rears didn't have that boss or bearing....V8 rear axles did and I would venture a guess that all quick change rear center sections did but would be very interested to know if the model A quick change used a model A pinion and thus lacked the nose bearing...

 

The AB size Pat Warren doesn’t have a supported pinion. I’ve got one.

 

The Halibrand 101 didn't use the nose bearing either.

 

Got it thanks. Ned

 

I just picked up a Halibrand 101 center section. It was listed here in the classifieds. 4:33 R&P, but no known gear sets. Are the gears 1" wide or 1 3/8"? After looking at the charts I was thinking a #3 23/24 or #4 22/26 gear set. I also need to do something with the shifter on the side of it. I think it's an in & out of some sort. Where can I find a tutorial or guide for this? I'm excited to add this to my roadster.

 

The gearset widths are determined by the depth of the change gear cavity. You should be able to just measure the length of the splines between the lower shaft bearing and the turned down portion of the shaft. They look like 1" from here.
As to the shifter: You might find a 1 piece lower shaft, but there is no reason that you can't just put it in the 'in' position. You might want to wire it to prevent it from accidently disengaging.

The sets I show are:
#2 - 23/24 (4.15/4.52)
#3 - 23/25 (3.98/4.84)
#3B - 17/19 (3.87/3.84)
#3A - 22/25 (3.81/4.92)
#4 - 22/26 (3.66/5.12)

All using your 4.33 R&P
My guess is that you will be happier with the #4 gear set @ 3.66 final ratio.

Bruce

 

It looks like a midget QC.

 

No it is definitely for model A Model 101

 

Thanks for the input. So is that shifter an in and out? If so, it would be good for flat towing.

 

Never seen one with a in and out shifter that wasn't for a race car.

 

The 101's come both ways, one without and mine with.

 

The new Winters early V8 center quick change doesn't use a pinion support either. In a quick change the pinion drive is facing the opposite direction and the end has the support on the spur gear not the pinion gear. So swapping out the original model A center section for a quick change is a much stronger upgrade. Not to many flatheads are going to break them.

 

In the circle track world even the supported bearing types suffered breakage including the bigger 301's & similar other brands, usually from a competitor hopping a rear wheel or backing into a another &/or the wall, many have been welded & successfully returned to use.

 

Here is one installed in a '29 RPU.

 

That sure is pretty Marty!

I sold my Pat Warren AB center. A rod shop owner probably saw my post in this thread and tracked me down, then was unrelenting in his pursuit to buy it for his client. I am sworn to secrecy what car it's for, but I can say it's a vintage race car getting restored to its original configuration.