Drive Shaft Coupler
 

I'm looking for dimensions/specs. and pictures for drive shafts and torq tubes '32-'48.
I have a '35 Roadster with what looks like a '46 Columbia.
Recently I had a noise that sounded like a bad u joint. I checked that and its good. Then took out the trans. and checked it out. Nothing looked to be causing the noise. Its out so I'll change the bearings and anything else that doesn't spec. out. Waiting on parts to arrive.
Then tear the rear axle apart. All looks great the ring and pinion mesh is perfect and its even bullet proofed!!
Where did the noise come from..... tear into the torq tube and there it is.
The pin from the drive shaft to the pinion sheered and the mesh of the splines is "real" bad.
There is a 6 spline adapter welded to the drive shaft tube that sticks out from the drive shaft tube 1.6875" and goes into the shaft tube .3125" for a total length of splines of 2". Behind the welded 6 spline part further into the drive shaft I can see there are 10 splines. Total length of the drive shaft measuring the contour is 68.156.
The torq tube measures 70"
The pinion is 3.78:1 with 6 splines on the pinion shaft.
What are my options for a fix on the shaft and pinion?
Also where is a good source for quality parts?

Re: Drive Shaft Coupler
 

So it sounds like someone made a custom driveshaft or modified the orig driveshaft to accomodate the later rear.Ford pinions were 10 spline through 1936 and went to 6 in 1937.You have what sounds like a 6 x 10 pinion adaptor welded into the end of the driveshaft.Ford actually made this part specifically to allow the replacement of the earlier rears with later ones.They were also available aftermarket for years but with Joblot automotive going out of business last year the supply has dried up.You need to determine if the pinion splines are still good.Assuming the splines in the driveshaft are bad you could have a new one made using tubular steel and a regular ford 6 spline coupler welded into the end and the front of uour existing shaft ( the universal end ) welded into the other end.Sounds easy but the problems are finding a shop that is willing to do it .The OD of the coupler has to be reduced or enlarged ( a bushing welded on ) to properly fit the id of the new steel tube . It all has to be precision fit and welded to avoid excessive runout. You may be able to do the same thing usung your existing shaft depending on how it was modified the first time.In other words,can the offending 6x10 be removed leaving enough length on the shaft to fit the new 6 spline coupler.
Of course ,if the pinion splines are trashed that would require replacement but i have had factory pinion couplers that have had all the splines wore out of them and the pinion splines still be good. Hope this helps,Bob

Re: Drive Shaft Coupler
 

The spines on both the pinion and the drive shaft are wore too much. Sounds like I'll need both ring and pinion replaced?
Along with a new end welded to the shaft.
Where is a good place to get a quality ring and pinion?
I see 6 spline adapters in Mac's catalog.Could that be modified and welded to the drive shaft?

Re: Drive Shaft Coupler
 

Rob, could you post some pictures of your existing driveshaft and also a close up shot that shows how that six spline coupler is welded into or onto the end of your driveshaft? I would appreciate seeing those pictures before I recommend two different possibilities that I am aware of for replacing the driveshaft in your 35.
If your six spline pinion is heavily worn, your best bet is to replace that gear set, with a new or good used ring and pinion matched set. The new gear sets sold by many of our Ford parts suppliers, are more than likely, all coming from the same manufacturing source in Italy. The sets like you need sell for ~ $350.00. The folks I personally know who have used these new gear sets all say the quality is good, and they are holding up well. You may be able to find a good used set for half that price or less, but sometimes this takes too much time to locate good ones. However, one of the most important things you can do is setting these gear sets up correctly with regard to bearing preloads and gear mesh/backlash.

Re: Drive Shaft Coupler
 

The set in my 42 was from Speedway, and are from Italy as well.
I think it was close to $600 for everything, new gears bearings gaskets etc.
Speedway did not have the gaskets I got them from Mac's

Re: Drive Shaft Coupler
 

Posting pictures of the modified hollow tube type drive shaft that was in RobR's '35 Roadster.

Re: Drive Shaft Coupler
 

Be aware that the splines in new reproduction 6-10 adapters may not be concentric with the outer diameter. In this case you have to index off the splines to machine it.

John

Re: Drive Shaft Coupler
 

Another thing to be aware of is that pin. Usually a sheared pin is an indication of a pin that's too hard. It should be a soft pin, hard ones shear. The pin doesn't transmit any power, it's just there to stop the drive shaft moving backwards and forwards.
Of course your pin may have been soft and got sheared due to the excess movement of the two apparently heavily worn splines. A hard pin is a relatively common mistake.
The pinion splines definitely to worn? That would be a shame.
Martin.

Re: Drive Shaft Coupler
 

Thanks for the advice and guidance guys.
The pin was the soft type and the splines on both the pinion and the drive shaft are too far gone.
Very good point to look at on the adapter not being concentric.
I agree it's totally a shame that the pinion splines are shot. The mesh on the ring and pinion barely have wear.
To bad I couldn't just replace the pinion. I know I can't though.

Re: Drive Shaft Coupler
 

speedway sells the drive shaft "kit", which is a hollow shaft with the front welded in place, you cut the tube to your length and slip in the rear coupler and weld it up. about 300 bucks i think

Re: Drive Shaft Coupler
 

This kit has been off the market for several years.

Re: Drive Shaft Coupler
 

Thanks for posting those pics for me JM 35 Sedan.
Looks like I'll end up with a rebuilt rear axle. New ring and pinion and bearings.
Are there any good reference books on the setting of R/P, preload on the pinion,mesh tolerance specs,torque specs?
I've never done one but would like to learn how.
With that completed all I'd have to is figure a good fix/replace/repair on the drive shaft.
Any more ideas out there?

Re: Drive Shaft Coupler
 

I would be suspicious of the metal in what you have. That end piece could be "soft" metal, the original couplers were pretty hard stuff. Get a later coupler and check for play. Any good machine shop could bore what you have and weld a later coupler in or some combination of the same.

Re: Drive Shaft Coupler
 

Tom Endy has a good tutorial for Model A rear axle. The main difference from V8 is rear pinion bearing. You have to remove and install pinion as a unit. Also a Motors Repair manual for the year gives a good overview.

http://www.santaanitaas.org/wp-conte...vised-2014.pdf

John

Re: Drive Shaft Coupler
 

Thanks John.

Re: Drive Shaft Coupler
 

Rob, I will email you some articles that I have on rebuilding these early Ford banjo rears and also call you to discuss this as well.

I recently went through a complete rebuild and gear ratio change on my '35 fordor sedan (Avatar). I took step by step pictures during this rebuild, planning to do a writeup to go along with these pictures, but who knows when this writeup will be finished. This rebuild used an original matched number set of 3.54, 10 spline pinion gears, so no change was necessary to the rear splines of a stock '35-'38 hollow tube type drive shaft.

I am getting ready to completely rebuild another '35 rear using an original matched number set of 3.54, 6 spline pinion gears, because I don't have another 10 spline set of that ratio. In this rebuild I have decided NOT to go the route of modifing a stock hollow tube drive shaft by welding in a six spline adaptor/coupling in place of the 10 splines. What I am planning to do is use a solid type '37 to '41, pn 68-4605-B, drive shaft with a 6/6 spline original Ford coupler that's pinned in place, and a '37 to '41 center bearing torque tube with a Skip Haney replacement center bearing. This will all bolt up and look totally original except for having a zerk grease fitting located on the outside center of the torque tube. I am thinking/hoping this will avoid the pitfalls of having a tube type drive shaft modified, that could windup being problematic like the one you have, and others I know who have had the same thing happen

Re: Drive Shaft Coupler
 

Sound good JM. Thank u.

Re: Drive Shaft Coupler
 

I was afraid of welding over the splines due to srinkage. I took an old input shaft and cut the splines short and put it in the 6 spline coupler. I welded it to the end of the coupler. I made a sleeve to go over the stub and welded it on and then turned it concentric. The assy was put in the tube and carfully positioned and welded. The coupler end of the shaft was put in the lather and heated untill the other end was running at less thean .005 TIR.
The biggest concern I had was the torque tube being crooked. I mad a tool to check alignment. If the tube is out, the splines will have a reversing load on every turn.

Re: Drive Shaft Coupler
 

Sounds to me this welding a coupler to the tube shafts is
a very tricky thing to do.
What is the success rate out there that some of u that have done it or people you know that have done it?
I've found a drive shaft shop that said they could do the job,weld the coupler, straighten, balance but would like to have the pinion and the coupler that I said I could provide them.
The 6 spline coupler is looking to be hard to locate. Mac's said there waiting and won't receive more of them till the end of August.

Re: Drive Shaft Coupler
 

One method of doing this, that I was told about and was claimed to have been successful, was concentrically boring out the 10 splined pinion end of a tubular drive shaft just enough to give a slight press fit with the OD of an adaptor/coupler before pressing it into place. Then with a six spline shaft placed inside the coupler, both ends of the drive shaft were aligned in a lathe while the 6 spline coupler was welded in place on the end of the drive shaft.