A and V8 Driveshafts Different?

[jeepguy1948]

I need a little help sorting out the differences are between a Model A driveshaft and a V8 driveshaft. I do not at the moment have any disassembled torque tubes around to allow me to see for myself so I need a little help. As I understand it a Model A uses a 1 piece driveshaft but a V8 uses a 2 piece driveshaft with a splined stub attached to the pinion and a splined coupler to attach it to the driveshaft, correct so far? If those 2 things are true then can that “pinion stub” be used on a Model A differential or must a V8 differential be used? These questions all pertain to installing a Borg Warner overdrive into a Model A.

[cas3]

The A differential is completely different in all the parts, bearing sizes etc. You will have to make your own set up work. The whole OD trans, or just the OD unit in the drive line? There was a guy years ago making the OD unit to fit in the modified torque tube, much like the new Mitchels.

[bobH]

Whichever way you want. There have been a couple guys that I knew that were doing model A's, both gone now. Borg Warner or Volvo into Model A. Or, same into a later V8 diff adapted to model A. Your choice. I don't get your comment about 2 piece V8 driveshaft. Maybe you are questioning how the d/s mates with the pinion. And, yes, starting in late 32, the d/s mated via a coupler. No big deal. Perhaps that is the route you would rather take. But, that leads to figuring out how to put a Model A spring on a V8 housing. In my view, putting the B/W OD into the Model A d/s, would be the simple approach, and indeed, that is how guys have done it in the past. Several ways to skin a cat. Pick your poison...
(There is one exception, regarding what you call 2-piece V8 driveshafts... 39, 40 Merc used a driveshaft that did not have a coupler, but rather the d/s was one-piece with the pinion. If you are searching for V8 diff's, you could possibly run into one. Otherwise, you will find a coupler, late 32 through 48.)(In case you need to know, Model A through 34 are the same width, drum-to-drum. And, the so-called 40-style is only an inch wider per side -- 2 inches wider overall.)
As for the 'stub pinion' being put into a Model A diff, I don't know. But, there are many talented machinists that have created various combinations. There are guys that have adapted a later 35-up V8 center section into 34 'Bells', and have worked out the details. So, if you are that talented, nearly anything is possible.

[cas3]

I put model A bells on a 35 center once. The tubes where they leave the bell are similar in size, cut em off and weld it up. But...I did this at home, and who knows how straight it all was. Lost the car in a fire so never got many miles on it

[V8COOPMAN]

Originally Posted by jeepguy1948

If those 2 things are true then can that “pinion stub” be used on a Model A differential or must a V8 differential be used? These questions all pertain to installing a Borg Warner overdrive into a Model A.

jeepguy.... Model 'A' drive shaft is shown in first picture with its REMOVABLE pinion gear still attached.




You can see the LONG shaft and separate pinion gear in the SECOND picture. The SHORT STUB shaft goes with kit in pictures #3 & #4.




Apparently, "SPEEDWAY MOTORS" makes a kit that allows you to convert a Model 'A' to OPEN DRIVE (3rd & 4th pictures BELOW), which I THINK is what you want to do?






Coop

.

[jeepguy1948]

Sponsored Links (Register now to hide all advertisements)

Dang, I wrote a very long description of my situation but then deleted it. Here’s the situation as best I can describe it (Coop, I only can see the first picture, anybody else?) So, I bought a Borg Warner OD installed in a Model A torque tube attached to some type of diff and installed in a running driving car (except that there was a chipped tooth on the ring gear caused by the PO forgetting to turn the OD off before shifting into reverse. I bought it from a friend that wanted to go in a different direction. When we disconnected the torque tube from the diff we ended up with a short, splined shaft attached to the pinion and a sleeve coupler on the aft end of the driveshaft that went to the OD itself. Now this is critical: I have never taken a Model A or V8 driveshaft before and my friend has also never taken a Model A driveline apart but he HAS taken a V8 driveline apar so he didn’t see anything wrong. The question is..... do I have a V8 driveshaft adapted to a Model A diff or do I have a V8 diff adapted to a Model A? I don’t know. There was at least one and maybe more businesses that adapted to BW OD to the Model A but I don’t know what parts and pieces were used. To make it even more complicated I have decided to go with the 5 speed and have sold the OD to a member of our local club. What say y’all?

[cas3]

The female sleeve over the pinion on the rear end is v8 differential norm. I'm not familiar with the speedway kit mentioned above by Coopman. If the rear end came out of a model A the spring perches on the ends would look like ford factory forgings. If spring perches look welded on, it a v8 rear end. I do not think the torque tube bolt pattern is the same, but never tried it. Many folks in the model A club here like those 4 speed overdrive trannys from a mid 80's ford ranger as they fit in the A with out hacking the center crossmember, and the shift lever comes thru the floor in very much the correct spot. there is also kits to keep it closed drive. I have some junk here, I could stick an A tube on a v8 diff tomorrow and see if it would bolt on

[V8COOPMAN]

Originally Posted by jeepguy1948

When we disconnected the torque tube from the diff we ended up with a short, splined shaft attached to the pinion and a sleeve coupler on the aft end of the driveshaft that went to the OD itself. To make it even more complicated I have decided to go with the 5 speed and have sold the OD to a member of our local club. What say y’all?

jeepguy & cas3.... I don't know what happened to the other three pictures, but I'll try to make it up to y'all.

Jeepguy... It sounds like you have a Model 'A' rear end there because Model 'A' rears DO have a pinion gear that sits on a drive shaft with tapered/keyed end. The kit that I described from Speedway uses a short, tapered stub shaft with the standard Ford six-splines on the opposite end. This should be apparent on the one picture you CAN SEE, my original post.




BELOW is what the Model 'A' pinion gear and bearing looks like mounted on the shortened, tapered stub shaft.





BELOW is a link to the SPEEDWAY kit. You're going to need to convert to this OPEN DRIVE configuration to accommodate your 5-speed, hopefully you're considering a T5 for your transmission. I would be happy to discuss & help you select an APPROPRIATE T5. You can certainly pick the wrong one and end-up very unhappy with it.


https://www.speedwaymotors.com/Speed...Kit,40133.html


I have also included a link BELOW this paragraph with a very comprehensive article showing the installation of a T5 in a Model 'A'. Although there are a couple of important details that I do NOT agree with in this article, it is a fairly good rendition of what you will be up against to complete your conversion. Link BELOW!

https://clampdowncomp.com/tech/insta...-model-a-ford/


Coop

.

[jeepguy1948]

I appreciate the advice about installation of the 5 speed but that is not the purpose of this thread. The purpose is to figure out what must be done to install the BW OD in the Model A of the guy I sold it to (the OD only, not the car). I believe that it boils down to this: how did the manufactures of these kits (a BW OD into a Model A driveline) do it. Once again the question is this..... Has a V8 pinion shaft been adapted to work in a Model a diff, or has a V8 diff been adapted to fit in a Model A?

[jeepguy1948]

The friend that I purchase the OD from still has the diff at his garage but he is 150 miles away so I can’t just look at it.

[bobH]

Originally Posted by jeepguy1948

I appreciate the advice about installation of the 5 speed but that is not the purpose of this thread. The purpose is to figure out what must be done to install the BW OD in the Model A of the guy I sold it to (the OD only, not the car). I believe that it boils down to this: how did the manufactures of these kits (a BW OD into a Model A driveline) do it. Once again the question is this..... Has a V8 pinion shaft been adapted to work in a Model a diff, or has a V8 diff been adapted to fit in a Model A?

In response to your last sentence... My friend in San Dimas (passed away, my memory of what he told me) took customer d/s and torque tube, did the machine work and welding, and returned same to you with B/W installed. He often supplied the B/W too. No V8 parts were used. I'm aware of many that he did for the Model A community. There ought to be a Model A guy (probably in socal) that has one of these set-ups, and can elaborate. Have you tried the 'A' forum, or other 'A' sites?
Additionally, the guy in Bakersfield that was doing the same thing using a Volvo OD.
BTW, my friend in San Dimas was charging substantially for this conversion. Back at the time, it seemed to me that doing a Columbia was almost a wash, financially. This was at least fifteen years ago.

[Bob C]

Most if not all BW OD installed in Model A's involved cutting the Model A driveshaft
and torque tube and installing the overdrive in the middle. Maybe the article
in the link will help. http://www.santaanitaas.org/wp-conte...r-Apr-2005.pdf

[V8COOPMAN]

Originally Posted by jeepguy1948

I appreciate the advice about installation of the 5 speed but that is not the purpose of this thread. The purpose is to figure out what must be done to install the BW OD in the Model A of the guy I sold it to (the OD only, not the car). I believe that it boils down to this: how did the manufactures of these kits (a BW OD into a Model A driveline) do it. Once again the question is this..... Has a V8 pinion shaft been adapted to work in a Model a diff, or has a V8 diff been adapted to fit in a Model A?

V8 and Model 'A' PINION GEARS are different. Late '32 through '34 V8 pinions are one piece with a 10-spline slip joint protruding from the rear end housing, as seen in TWO PICTURES BELOW. 1935 thru 1948 are very similar in construction.







Late '32 V8 thru 1948 torque tube flanges are SCALLOPED, as seen in two pics BELOW.








One more note: The splined pinion shafts used in the V8 rear ends connect to a drive shaft with this splined COUPLER, BELOW!





Seen in link BELOW... A typical B-W unit conversion back in the day, spliced into a Model 'A' torque tube. Click the link BELOW.


https://www.jalopyjournal.com/forum/...#post-12083604


NOTICE that the Model 'A' flange on the center section where the torque tube bolts-on is ROUND. Picture BELOW also shows Model 'A' ROUND Torque Tube Flange.





REAR, tapered end of a Model 'A' drive shaft, where pinion gear mounts, BELOW.




Model 'A' Pinion Gear, BELOW.





So jeepguy, I don't know who was putting these B-W O/D units into Ford torque tubes back in the day, but there were apparently quite a few done like that. Going by the pictures in the link above, as well as all that I have seen over the years, these entrepreneurs must have done some cutting and splicing of model 'A' drive shafts and torque tubes.

If you'll look at the clues I've pointed-out above, you should be able to figure whether or not you have a Model 'A' rear, or a V8 rear. I hope that I've helped to clear-up your questions for you. If not, shout back AGAIN!

Coop

.





.