34 / 36 driveshaft

[3W Hank]

I might be wrong out here but like to ask.
I has not more HP than say 200 at the best and will not do any burnouts but might like to rew the FH way over 4K.
Car is light, 32 5W coupe.
I has a 37 rearend with std drive axles, Ford 4.44 gears and 31” tall tires and transmission is a Lincoln 39 whit the 26T.
I has a 34 TQ driveshaft.
-I’ll just cutted up a 36 driveshaft that will be header collectors.
Ends look like the 34 at both sides but the 34 driveshaft is ca ; 45 mm or 1.77” and the 36 driveshaft ends is ca ; 50 mm or 1.97”.
The 34 TQ tube is on smallest end inside ca ; 52 mm or 2.05”, so it is possible use a high grade seamless 50 mm tube or a 2”.
Ok, now I think the 34 std tube will not break, or after the drive axles, but one idea is a new tube might be more straight and create less vibration ( if that is or can be a issue on a 34 tube at higher RPM )
Just a thought.

 

[Flathead Fever]

I have a pair of those on the Mitchell Muffler Pickup. I had to remake one of the originals because it had cracked really bad. The problem with them is those driveshafts are thick and heavy hanging down below and the tubes coming out of the engine eventually crack, but that's what they used in the 1940s. Mitchell welded threaded ends on them with caps that could be unscrewed to uncork it. It took a while, but I found the threaded end at a plumbing supply store and welded it onto the new header. There exactly the same diameter as the outside of the driveshaft so that when the weld is ground off it looks like it came that way. I'm slowly putting the car back to how it was when it won an award at the first 1950 Grand National Roadster Show. It didn't take first place, but it won a trophy for its construction. I was lucky to find this pickup. My dad talked about building a clone of it but then I found the original one. It's not built from a pickup; it started life as a '28 AR roadster car cutoff behind the seat and then a Studebaker rear was welded onto the roadster's body. That way when the top was folded down it disappeared behind the seat and then it had a tonneau cover that snapped over it so it couldn't be seen. The bed is from a '25 T that was only produced for a few months. I need another one because somebody shortened it, and it wasn't Dave Mitchell. It's Just about impossible to find one a good one.

Be careful with those lake pipes, they burn you bad if you don't pay attention getting in and out of the car. I've been burned, my daughter has been burned. Just takes a second of forgetfulness remembering they are there when you get in and out of the car. It hurts!

Here's some history about the pickup.

https://www.jalopyjournal.com/forum...liability-run-mitchell-muffler-pickup.472428/

 

[3W Hank]

I plan to has the collector under the frame as idea was from this 34 3W.

Any thought get a 2” tube in a 34 TQ ( use the 36 ends.

 

[alchemy]

You think the steel tube you will find nowadays is better than the stuff Henry Ford forged himself?

 

[3W Hank]

So you think ex M/W cant do driveshafts, :- )
Henry used good steel, and if we forgett what China get us there are steel, but as I said a idea I noted when working on the collectors from a 36.
I can say we do allot of **** stuff now but you get what you pay for and today its qauality aviable and this is a bigger diameter.
I found a older thread and one had done this.
But again, my driveshafts axles will failure befire this 34 tube…

 

[rotorwrench]

The old early straight tube drive shafts can take a lot. They can be checked for bend on either a flat surface or on V-blocks/rollers.

While there is some steel tube available that may be stronger, I would guess that a bird in hand is not a bad thing. We used to have a guy in the fold that made drive shaft kits but he passed away some time ago. As cantankerous as Dick Spadaro was, I still miss having him around. Most use a good front spline section like you have there and get the closest thick wall tube they can find to mate it and a rear coupling to. Generally folks are building shorter shafts for AV8 applications. It may take some lathe work on both ends but that's just part of the fun.

 

[Andy]

My 32 5W had a 50’s. built 276 flathead. It had the stock 32 rear with 3.54 gears. It never broke.
Are trying to make a driveshaft for your car?
It is really trickier than apparent as the driveshaft/torque tube length is critical. The length has to be right to get the speedo gear to fit the snap ring position.

 

[3W Hank]

Yes.
I has a 37 rearend.
I bought a 34 TQ so its need to be cut to get in the 32 frame and the rear tires at correct place in wheel openings ( Lincoln trans/stock K-member )
As I cut up a 36 driveshaft ( header collector ) I notice it has bigger diameter inner driveshaft than the 34.
The 36 has the same ends on the driveshaft as the 34 but tube is bigger OD.
I realise as I said if my Henry 34 is straight it would not go dead before the rear axles on transmissions.
Now, a buddy need a stock 34 driveshaft so I got the idea go for a 2” chrome molly at wall .060”.
So anyway, it was a idea.

But now I realised rear part has a 10 spline and my pinion is a 6 spline.
I has a sleeve ( se picture ) as I think is from a 37 banjo ?
But it has a solid axle ( now cutted ) spline is both side 6 splines.

I seen Van Pelt sell sleeve both 10 and 6 spline but its not say on OD.
So in my case, say I use the 34 tube, will that be welded in tube and pinion in direct in tube ( not as a sleeve and dual dowel pins )

https://www.vanpeltsalesstore.com/V...pling-Sleeve-for-6-spline-coupler_p_1870.html

 

[3W Hank]

I notice the earlyer piniong was 10 spline later it was 6, my I think is ca 37.
Also 32 it was solid driveshaft but then 34 it was a tube, then 35/36 it was a conical tube but at 37 Henry went back to a solid driveshaft and a sleeve with dual pins.
I guess I need find a end that are 6 spline and OD 1.75” or 2”.

 

[Brian]

Hank, those 10 spline/6 spline adapters are about 46 mm dia. You can weld that into a bit of tube to make a tubular driveshaft with 6 splines.

 

[cas3]

Brian is correct as usual. I did a long thread here about 6 years ago with all the drama I went thru. Sorry, its not book marked, so you could search 34 drive shaft in my name.

I have a lathe, so all cuts were precise. i tried to hire a local company that builds drive shafts for a living, and they had no way to hold it. normally they mount off a U joint.

so I welded it myself with a dial indicator to track the movement as I welded, still not perfect. Then I looked all over my 3 million pop area for a place to balance it, no luck.

Then, I forget his name, a semi famous rod builder chimed in that he does them all the time, tig welds 4130 tube, ready to install. Thats all I got

 

[3W Hank]

So in the end, was it straight and working ?

 

[3W Hank]

Question.
How important are the front bearing surface in this design.
On the 34 I has look decent but the 35/36 is a tad better.
Its used and one feel some wear from bearing, but measure it dont show much.

In balance a bar its all based on how straight it is. Thats the key.
A normal yoke driveshaft has fixtures for the balance work but this is a welded on outside spline at the transmission side and the other side its a inner spline.
But one can install the pinion and a pin.
So true place on V block is transmission side bearing surface and the other side at the pinion.
If the tube ( OD 1.75” ) is decent out of roundness at mid, it would be good.
What decent is I cant say but zero is best or maybe 0.001”.
-So key is straight, not balancing.

I cant test my std 34 on V block now as I dont has a 10 spline pinion and the end outside diameter there is ugly.
But I will test it on the tube ends.

 

[Brian]

You don't need a pinion; just turn a piece of steel to just slip up the splines [on the inside dia of the splines]

 

[3W Hank]

Ok I can do that.

checked the std 34 on V block at run on mid ( CC = 40” ) and tube is not really round and runout was over 0.01”.
I also noted a press down slighty at my tum it swapped 0.01”.
From tube to splined end where bearing is was not much out of roundness.

This shaft will move allot inside the TQ thats for shore even at medium RPM on engine.

A chrome molly OD 2” and 0.06” wall will be way more stiff.
Just my conclusions look at this.

 

[3W Hank]

Runout 0.32 mm or 0.0125”.

 

[Duke]

I had a talented friend with a big lathe shorten mine. He measured the runout before and after and he had it straighter after. The 36 transmission end can be turned down to fit into the 34 tube. I wonder if you could use a later solid driveshaft so you have the correct splines? I also figured out to measure and measure again so that you get all the lengths right. Put the the driveshaft on the rear and note the lengths from the torque tube mount surface to the bottom of the driveshaft with the pin in, then use that to figure out shaft length in the torque tube. Do not use lengths found on here or anywhere.

 

[3W Hank]

Yes I will do that in mock-up.

Question.
I do note the 35/36 has a end at 10 splines as the 34, but one told be tiday the 34 had 6 splines ( is that really correct ?

 

[3W Hank]

I got info a 34 has 10 splines at rear.

I might do this.
The racing tube DocolTube is better than chrome molly in both strenge and tolerance and are actually made 20 minuts from me ( Borlange/Sweden ) sold by M E Racing.
Are in NHRA nitro fuelers and promods now.
50 mm and 2,5 mm wall makes a inner diameter at 1.771” and the 35/36 front splined axle has a OD at 1.782”.
So I has to grind it down some.
The 34 TQ tube is at 52 mm at the narrow part so a 50 mm tube will be Ok.
Tube is not expensive and I need to make a new rear part to 6 splines anyway even if I used the std 34 driveshaft.
Its no way that tube will swapp by press a tum at 40” CC.
A good welder is needed.

 

[3W Hank]

checked for fun my race car 3” chrome molly driveshaft from M/W today and on mid the runout was 0.008” and wall thickness on those is at 0.083”.

I got a 49” long Duroc R 8 2” tube with wall 0.11” ( it fit perfect on the 35/36 splined part with pressfit ) but a 2” tube is to big to fit in the 34 TQ tube and run out on mid was allot ( to bad )
They told me at the shop it will be extremly hard to weld the end part from the 35/36 driveshaft and not let it bend away as pressfit part is 1.5” long in the tube.
If that splined axle is not straight it will cause vibration and wear.

I might can get a 50 mm ( 1.968” ) tube in the TQ tube but more room might be needed.
I dont know how much clearance I need in TQ tube, maybe 0.08” is Ok.

The 2” tube was rather heavy..