building a 34 drive shaft

[rich b]

Originally Posted by cas3

33-34 tubes are .100 wall thickness. rich, .095 would certainly be close enough for me, what did you find, dom, or aircraft 4130? this was two years ago when the two companys near me said that size was not made. at that time i only had one shaft, and it had a bad front. about that time i also found out speedway, and spadero shafts were no longer made. i now have enough bad shafts that i dont need any tube, just have to make the ends. thanks, skip

Spicer driveshaft tube

http://www.northerndrivetrain.com/pr...0-62-7400.html

Interesting that Dick's tube kits were only .060 wall. Seems thin compared to
my experience with PTO driveshafts on equipment. Maybe that's why people have told me they twist up, always equated that to confusion with Speedway's kits.

[rotorwrench]

The .060" tube would likely be fine if it were Chrome Moly structural steel tube. The 4130 is some strong stuff. If using a lighter duty steel then the .095" + might be a safer bet.

[cas3]

rich b, good info, thanks

[HIGHTOWER611]

I appreciate all of the knowledge from you guys here as well as what the driveshaft builders locally here say. I supply them as Dick had them. I am sure a poorly built shaft with a thicker wall could fail as well, but a poorly built shaft with a thinner wall would fail quicker. Some great arguments here. If you were to build a shaft as cas3 or with a kit, the most important thing is alignment after you choose your tube. I have heard some people set them on the inside of angle iron to line up. I would question any accuracy with that method. I prefer to put between centers and check runout before welding. I also like Lawries method. I will be building my own shaft soon. Thanks for the info!

[cas3]

some straight and balance stuff https://www.youtube.com/watch?v=tm7DhP3M4AA

[Pete]

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Originally Posted by cas3

some straight and balance stuff https://www.youtube.com/watch?v=tm7DhP3M4AA

A lot of really bad info in that video.

[cas3]

pete, you are always short, and to the point! i love it, but let me know your thoughts please, thanks, skip

[Lawrie]

I can see one furphy, when heating the saft to straighten it ,you need to heat it where the bend starts from,not anywhere.
Lawrie

[Pete]

Lawrie is right. You heat with a small tip in a small area, no bigger than a pea. Then you cool the heated area, NOT all over the end.
NO HEAT in the middle of the shaft. The tube is straight to start with. It comes that way. The only place it is bent is where it was welded. You straighten it in the welded area, usually no further than an inch back from the weld. Many times you can get it straight by just peening the low spot RIGHT ON THE WELD.
You can not get a close balance by watching a vibrating dial indicator. You need a balancing machine with electronic pickups.

Welding weights on anywhere is Mickey Mouse, even though the factory does it. What do you suppose happens to your newly straightened driveshaft when you weld a weight on???
IT BECOMES NEWLY BENT!
There are several ways to apply weights without welding but the easiest is soft solder applied with an electric soldering iron.
The heat to apply is not enough to affect straightness and properly tinned on, it will easily stand 10K or more rpm.

I used to build drivelines and rear ends for Penske Racing so I know the way I do them works.

[jimvette59]

I agree with you Pete. I worked on high speed high temp pumps and the rotating element has to be dynamically balanced. JMHO.

[cas3]

i will say i was surprised to see they're balance method too. this place, near me, http://www.cem-web.com/ continental machine, has done some shafts in the past for me. i was always impressed with the machine they use. its a long lathe with a chuck on both ends, and an automatic welder, and spin balancer all in one. i watched another youtube thing of a guy straightening long, solid inboard boat prop shafts using the "pea spot" method. i like lawrie's idea of grab the male end and see what i got for runout at the far end. should get my parts back soon, i will update then. thanks all, skip

[34billct]

After many attempts to get a good drive shaft vibration free I changed the gears to the new ten spline 3:54 gear set and found a good stock drive shaft and took it to an electric motor shop that can balance armatures. They do not need to run it on centers. they run it on rollers with a drive belt and can tell exactly were it is out of balance and how much weight to add and where. I JB Welded on the weight on and brought it back to check and it was spot on. Now i need a good tight front roller bearing and i should be good to go.

[JSeery]

I have a shop near me that has built drive shafts for me for years. They also balance drive shafts. No matter what I attempt to do on my own it ends up cheaper to go through them. They are even cheaper than what I can find going the salvage yard route! It is a shop that mainly deals with large truck drive shafts. If you fabricate your own drive shafts it might be worth you time and effort to locate such a shop to balance it for you.

[ctaulbert]

Originally Posted by Lawrie

I fouind the info,its a bit hard to read but they used AISI 1020 steel with.125 wall.
Lawrie

Since I shared that message with Lawrie, I've made another handful of '33-34 type driveshafts. This setup has worked well behind a sbc (spiritedly driven too) for 10,000 miles.

I start with an original '33-34 Ford front coupler, or have used '35-36 front couplers as well. The back end gets turned down for a 0.002" interference fit into a new tube.



For the rear coupler, I start with a new 6-10 spline coupler from VanPelt. The diameter gets turned down to 1.750", which allows the use of a torque tube seal from Danny Burroughs at Bruce's Rod Shop (a great piece for lowered cars). The tube end of the coupler gets turned down for a 0.002" interference fit into a new tube as well. Another thing I do is "cap" the tube end of the coupler. This prevents any oil from migrating through the splines (again, on a lowered car) and entering the hollow tube.



Now for the tube....In my message to Lawrie, I had used some plain DOM mild steel for that project. It has served well with no issue. Since then, I've moved over to using 4130 chromoly seamless tubing only because I can more readily get the material (often times from Aircraft Spruce).

I've found most original tubes are 0.095", but I've occasionally seen slightly heavier wall thickness. I've been using 0.120" wall, only to increase the bending stiffness of the driveshaft.





I use my lathe, when the length permits, to weld the shafts in an effort to keep them as true as possible. I have a local machine shop that has the capability of balancing these shafts, so I take every one I make to them. I'm sure it's overkill, but for $70, it's worth the added peace of mind.

[cas3]

wow, finally some facts. thank you cory. i like to do these "how to threads" for the record, to help others in the future, but at the same time, i am usually the pioneer. so thanks, good notes for the record

[cas3]

so now, another update on my progress. i got my parts back from the welder today, and even though i told them i only have a mig welder, and this should be tigged or arced with 7018, they miged it! its a nice looking weld, probably a better machine than mine, perhaps better grade wire, but still, not what we talked about. every time i hire some one......., never mind. so, some photos here, sorry i dont have the computer skills to lay it out correctly, but here we go. first i chucked up the male end to see how far out of whack it got from welding. first photo, i am chucked on the splines, and tail stock centered in my center i made. dial indicator showed 3 thou out. next, i grabbed on the actual bearing surface, showed 1/2 thou out. so, it did not go bonkers from welding. i then machined it to size for the finish. i discovered that i had not figured correctly on the spline length, after cutting the groove for the snap ring, on the lathe, its not too hard, length of the spline is the same except for the bull nose at the front. so, i have a virgin bearing surface. no photos of the rear piece, its not too exciting. i am going to take my parts to the drive shaft pros, since it should be balanced by them, they might as well weld it too. both of these shafts will be 9/16 shorter, one, because i used a 35& up ring& pinion in a 34 diff, and the other i used a later center diff center for a columbia -34 adaption i started 2 years ago.... will follow up on that later. thanks all, skip

[Lawrie]

Great work, It took me some years to finally get my33 vib free.
a couple of things that made a BIG difference was to get the front driveshaft roller bearing play down using original sleaves and rollers, the other thing that finally got the drive line vib gone was to fix up the rear mount on the rear of the trans where the torque tube bell goes over and is bolted via 4 fitted bolts,these holes had all worn as well as the bolts allowing the bell to sage down about .030 off centre.
I clocked up the bell using the trans mainshaft and reamed the holes and made new fitted bolts,I did a post on this a while back.
Lawrie

[cas3]

more good info, thanks lawrie. i had planned to use a later 2 piece clam, as i have a 34 that some one cut the original cam off. do you think the original style is a better fit?

[Lawrie]

I don,t know ,but look up my old post on fixing the drive line vib,its some where on the barn.
that was the main thing that got the 33 smooth
Lawrie

[cas3]

i presume this would be it, thanks lawrie https://www.fordbarn.com/forum/showthread.php?t=141800