Technical Which transmission for an AV8?

Hi, new member here. Just got an 8BA with a 3 speed column shifted transmission that came from a 1950 auto. Ultimate plan is to install in a Model A and have a 3 speed floor mounted shifter. I plan on keeping the Model A frame and torque tube. Before I get myself into too much trouble and expense I have a question concerning the transmission. Can I convert the present column shift trans to floor mounted and use in a Model A or do I need a transmission from a different year because of the Model A frame layout? If it can be used how would I go about converting it, as in what parts are needed or is there a kit available? Thanks in advance.

Tony

 

O,K, New guy. This gets asked multiple times a week it seems. This board has a real Kool way to find information. It's called a SEARCH menu. All you need to do is click on that Magnafying glass in the upper left corner. You'll be Amazed what you can learn just by reading.
The Wizzard

 

Wow, thanks for the reply Mr. Wizzard. When I said I was a new guy I meant I hadn't posted before, I've been reading this forum for well over two years. Yes I'm well aware of "the real Kool way to find information" I had spent several hours searching this forum and had not been able to find an answer to my specific question that is why I posted. It's meeting welcoming members such as yourself that keeps many people like me from doing anything more than just lurking on these sites. Please do me a favor and put me on "ignore" and never respond to any of my questions in the future.

 

Tony,


If you want to keep the ’50 transmission you will need to buy an adapter for the transmission to make it a floor shift. Be sure the shifter doesn't end up in the middle of your seat (unless you plan to run buckets). Next you will find that it is open drive and will not mate up to the Model A rear end. This leaves you changing the Model A rear end to open drive and adding support for the rear end to replace the torque tube you removed. An alternative would be to use the rear end out of the ‘50 (which may be too wide, check it) if it is available. You will still need to support the rear end since there is not a torque tube. Another route that would allow you to use the torque tube would be to get a ’32-’48 V8 transmission (the best gears are in the '39). I believe, but am not sure, that you will need a flywheel cover from about a ‘48 truck to bolt the engine to the transmission. The part that is left out is that the pre 1948 engines are shorter and easier to install in a Model A. Remember that you are still going to need to build pedal mounts and a wishbone mount since these were part of the transmission on the model A. Be sure to take the engine apart and check it out before you go too far since flatheads tend to have cracks that make them a bad candidate for a rebuild. You should take it a little easier on Mr. Wizzard. Unless he is psychic there is no way for him to have known that even though this was only your second post you had been reading the forum for over two years and that you had already searched the archives.


Charlie Stephens

 

Here is one way:

http://www.jalopyjournal.com/forum/threads/home-made-floor-shift.97533/

 

Tony; I'll not ignore you just as of yet. Charlie is correct, how would I know you'd been lurking 2 years? I just figured at 67 years old you may not have been aware of a search menu or how it works. Before you Boot me off your list of potential helpers check out the list of my input on this board. A partial explanation is that I'm just a few years Older than you and I'm a hunt and pecker typest so I tend to keep what I type as short as possible. If we don't know how someone needs to tell us. That don't matter if it's building a Model A or how a web sight works.
The Wizzard

 

Lots of good input from Pist-n-Broke .

 

Tony, that '50 transmission is too long for a Model A. In mine I have an 8ba, stock Model A differential and torque tube, '35 top loader, '48 truck bell, '32 Tardell K member, deuce rear motor mount, and '32 pedals. It all bolts together as if it was built that way originally. Later '39 gears are better but nothing actually wrong with earlier. Stay away from '32 boxes, anything '35 forward work very well.

 

Do you have the Bishop/Tardel book?Great info,a must have.

 

Gentlemen, thank you very much for your advice it is exactly what I was looking for. CTAV8 I think I will go the route you described. I want to keep the original Model A frame, torque tube and diff and add the K member. I'm off to find a 35 or newer trans. Thanks again

Tony

 

Why do you say stay away from the 32 boxes? You singled out that year only and it concerns me. I thought the '33-'34 boxes were about the same. I think '35 went to spiral cut gears for first (and maybe second, I don't remember) and agree that the later '39 gears represent the best of the evolution of the gear sets. But back to my question, why single out the '32?

Charlie Stephens

 

Tony, a couple of things: I strongly agree with Texas Webb on getting "The Book". Even though they use an earlier engine and later drive train, that book will give you confidence in what you're trying to do and keep you from going crazy. Vern has been doing this since the beginning and with Bishop they've really put it down. For example, they don't believe in boxing the frame with a stock or mild flattie and explain how the deuce style k member stiffens the frame where it matters and allows the rest to flex as it's intended. Stuff like that.
Also with my setup we had to trim the bottom flange of the firewall that supports the floorboard, bridge it with a gas pedal mount and cope out the underside of the new floorboard we made. Also had to rotate the 8ba fuel pump to clear the firewall. You will need to deal with the steering, forget the stock Model A. Vern has a great booklet on using a modified '48-'52 F1 box and it's also covered in the B-T book. Feel free to pm me anytime as you move forward and good luck.

 

Tardell 32 K member is right at $600.oo. Food for thought. 35-40 stock Ford item graphed into the A rails. Lets you mount trans to stock mounts, You can bolt on stock V-8 pedals as well as mount the anti chatter rods. 39 or 40 pedals let's you hang a Hyd master with just nuts and bolts.
The Wizzard

 

Charlie, I should have said '32-'34. The 18-7006 case has a shallower bell area and limits you to a 9" clutch. The 48-7006 and 78 prefix cases have more room. I got this from Mac Van Pelt's excellent book.
Having said that, I put a 9" clutch in my car and am very happy with it but my coupe is stripped down and probably weighs under 2,000 lbs.

 

Thanks guys I have the Bishop Tardel book.

 

Tony,

You should catch a few car shows. Post your general location and someone might suggest some good ones.

Charlie Stephens

 

Just a contrary opinion to make sure all bases are covered: Why do you want to use the A torque tube? Something stronger would make your life much happier, especially when you start leaning on the 8BA.

Another option for the trans: My '31 coupe has a mid-'70s Ford RUG trans out of a truck that is a 3-speed with overdrive; the car launches like a scalded cat and loves the highway.

At the SoCal AZ Second Saturday event yesterday.

Crappy picture, but there's a long shifter handle with a V8 knob.

 

X2, my pops has built his 28 a v8 roadster using this book as a guide line. Very very useful info.

 

Tony,

This might be (or maybe not) what you need to adapt the early Ford trans to you motor. Maybe someone could look and advise him as I am definitely not the person to do it. http://www.fordbarn.com/forum/showthread.php?t=181323

Charlie Stephens

 

Those are correct. I like the stamped steel since it's lighter but they all work.
On the stamped make sure the mounting holes are not egged out.
Also just to clarify from earlier post about the year transmission you woul look for. Top load passenger car would be up to '39 since '40-'48 are side shift. The innards are interchangeable but the cases are different. I think a column shifter on n AV8 is a bad idea. In addition, although the top load 78-7006 case was used in light pick ups as late as 1950, they were set up with open drive in '42 so have a different rear mount (bearing retainer). Not sure if the light truck gears are the same as passenger car..... May have shorter first gear.

 

I've found a 1941 pick-up 3 speed transmission with floor mounted shifter. Do you think this transmission would work on my 8BA mounted behind one of the bell housings mentioned in the above post? I haven't checked it out yet so I don't have the case id numbers or know how many teeth the main drive gear has.

Tony

 

It will bolt together but I think the internals are not geared for your application. Also, my earlier post should have said "78-7006" not "48-7006", which I've just corrected. Thank you to Charlie Stephens for looking over my shoulder.

 

I agree CTAV8, Van Pelt shows the 41 trans with a 14 tooth main drive gear and a 1st gear ratio of 3.52. I know I could swap the internals for passenger car gears but I think that would just complicate my situation. Since I'm not in a great hurry I'll just wait until a good 39-48 passenger trans becomes available. Thanks for all the info gents.

Tony

 

Tony,

I would only look for a '39 passenger car trans. The later ones were side shifters and would require you to buy an aftermarket shifter or add a column shift to your car, neither of which I would recommend. Remember that the '40-'48 gears will go into your '41 truck trans. Any chance the '41 truck trans you are looking at has the passenger car gears? Did you count the teeth?

Charlie Stephens

 

Your right Charlie, I don't know what I was thinking. Finding a one year only trans (39') is probably a daunting task. Any idea how much a 39' gearset would set me back; ballpark?

Tony

 

Tony,


You can build a “39” transmission from parts. The case was the same from ’37 to ’39 in passenger cars. The case was also used in trucks from ’37 to ’48. The later truck case carried the same casting number (“78”) but I think it had additional reinforcement (which is good). The ’41 case would fall into this category. The gears were the same in passenger cars from ’39 to ’48. The gears were the same ’40-’41 in trucks. When I say the gears were the same I am talking about the syncros. The ratios for first gear changed from the trucks to the cars and I believe possibly the cars had more than one set of gears available. The ’42 to ’48 trucks were open drive and had a unique open drive although some of the other parts may interchange. The ’39 passenger and the ’39-’48 trucks had a unique shifter that you will need to use. I believe the preceding is correct but I must admit I am not an expert on transmissions so check out what I say with the experts. The best source of information on the transmissions is Mac VanPelt, http://www.vanpeltsales.com/FH_web/flathead_home.htm. He wrote a book that is highly recommended and you should probably get a copy. Max Navarro, (310) 774-6723 might be a good person to talk with since he is in Southern California. Max also wrote a book. I haven’t talked with Max in several years but I assume he is still doing transmissions. In answer to your question about what are the gear sets worth, about $700 either original or reproduction but as with most other things the original is probably the better choice and you might get lucky on the price.


Charlie Stephens

 

Tony, Charlie, just one further comment. '39 gearboxes are undoubtably the best version but anything '35 forward will work very nicely and are much more available.
I have a stock '35 passenger 48-7006 in my car that we rebuilt. All the original gears and major stuff were in excellent condition. I've had no problems at all with it and really like the way it feels and shifts.

 

A question for future reference. If I found a suitable trans with the wrong gearing for a passenger car; 1st and 2nd too low, how hard would it be to change gearing? Is it as simple as changing-out the main drive gear and the second gear to the correct ratio and nothing more? Obviously I know that upon tear-down any defective parts would need to be replaced as well as seals and other consumables. One last question, on average how much can I expect to pay for a 1939 trans in good (usable) condition? Thanks again for all the great info you have provided.

Tony

 

I think that thr transmission you use in your A V=8 depends on the era of the build you are shooting for, using a later flathead gives you options for example that you would not have if you were building a '30s build. Make sense?

the absolute best transmission I can think of for an A V-8 is a '39, the best mod you can do to optimize it is to load it with zephyr gears. But a stock '39 is a major upgrade for a model A. or like as has been mentioned you can sue what you got and find a shifter for it. I think that Hurst was making the YoYo in the '50s and with your choice of engine your A v8 would have been a '50s build.

Ok someone else is going to say something different but those are the directions I would take it in.

 

Why load it with the Zephyr gears,what makes them special.