Torque Tube & Driveshaft Shortening

[Harrison]

I have already shortened my torque tube and now I need to shorten my driveshaft. Those familiar with old Fords know we're talking about (approximately) a 1.25" solid shaft - splined on each end.

The driveshaft and TT are from a '46 if I remember correctly. They are connecting a '39 trans to a '40 rear end.

The trans end is fine. The shaft slips into the yolk on the trans as is. On the other end I will need a 6 to 10 spline adaptor.

What's choking me up is the $100 quote I got from the machine shop to cut a section out of the shaft and weld it back together shorter. They say they can't cut the splines so just lopping off one end and re-splining it isn't an option.

Can I cut the end off and carefully re-spline it at home with a cut off wheel on my grinder. I'm thinking I can - unless it is so hard that the cut off wheel won't effectively cut into it.

Any thoughts?

Thanks, JH

[Deuce Rails]

I would think that cutting new splines would be easier than cutting, welding and balancing the driveshaft. Try a different machine shop.

Do NOT try to cut your own splines with a cutoff wheel. You'll butcher the job. (That's no comment on your ability, just your choice of tool for the job.)

--Matt

[alchemy]

I have heard somebody here say they cut their own splines with a cutoff wheel at home. And cutoff wheels can cut some pretty hard stuff.

But here's another way: The guy who shortened my driveshaft just welded the coupler to the end of the shortened driveshaft. Not sure if he turned the driveshaft down to fit inside the coupler or opened up the coupler. Maybe you could stick a couple pins in it too.


- alchemy


P.S. Maybe one of the axle shortening places could give you a better price on splining the shaft. Try someplace like Moser or such. You'd have to UPS it though, and that may cost more than it's worth.


P.M.S. I just looked at moserengineering.com and they would charge $55 to respline it. Plus UPS. What's it worth to you?

[porknbeaner]

I'm with deuce rails.
Here's the deal if its too hard to cut splines then you shouldn't be cutting and welding it.
Cutting new splines in a drive shaft isn't any harder than shortening and resplineing an axle. Call around and find a competent machinist.

[Zodoff]

Cut it,and turn it down to accept the splined tubepart from the rear axle and Weld the shit together. If they are similar to 46-48 aksles that is.
There are some stuff about it in techomatic i belive.
Haha,alchemy beat me to it..... http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif

[Andy]

I do not think anyone could cut the splines by hand. The metal is soft enough but the accuracy required is way to difficult.
Options.
1, Send it to Bob Wilson of brake fame and have him respline it. Cost of his labor a and shipping would be considerable.
2, Shorten 35/36 shaft. Possible but difficult to keep straight.
3, 33/34 shaft. Might be to short from what you say.Hard to find also.
4, Make new shaft from tubing and existing ends. That is what I am going to do for the 32. You may need a shaft that is too long for this and not wip.

Anything but the first will require you to redo the torque tube. Another thought would be to weld the adapter onto the existing shaft and end up with a permenent female splined end on the shaft. Why not?

[Kevin Lee]

Man, I just went through this exact thing. blakmerk put a few hours into shortening my driveshaft.

The reason you WON'T be able to just cut and respline is because the shaft gets smaller right behind the splined part. Brad shortened mine by cutting it to length and building up the end with weld. Then he milled new splines into it. He shrugged it off as no big deal but I know It was more work than a cut and weld job. And just so you know there is no common heavy walled tub that slips over the shaft without machine work - I had already tried to think of a simple cut and weld I could do in my basement.

You're probably going to get a few responses here that will say something like "Just take it to a driveshaft shop and have it shortened. Shouldn't be more than 50 bucks." Let me just tell you that I couldn't find a driveshaft service in the KC Metro area that would touch it. And if someone tells you to "Just get a 33-34 driveshaft" I'll tell you the only one I was able to dig up was at Vaphead's place for about $280. But if you get lucky and find a 33-34 you're golden.

I hope you find an easy way to get it done - because I have another shaft I'll need shortened here in a few months. I'm thinking I'll just pay to have a tubular shaft made for the next car. Good luck.

[Pist-n-Broke]

Generaly re-splining the shaft is a problem in that o.d. steps down behind the existing splines. I have cut and welded many of them and never had a problem. The process I've used is to cut the shaft then counter boar a 1/4" hole 2" deep in the end then champfer or weld prep the cut to the edge of the counter boar. Then on the other half turn the shaft to a 1/4" x 2'plus stud and weld prep the edge. Press the 2 together and tig weld them together and dress off the weld. I've never had a viberation or one break. It's about a 4 hour job.
The Wizzard

[Harrison]

Damn, that $100 isn't sounding too bad now.

I think I'll get the 6-to-10 spline adaptor ordered, toss the driveshaft into the truck, and hit a few machine shops to see who can do what.

Cutting the end off, turning the shaft down, and welding it to the adaptor sounds fairly easy.

JH

[alchemy]

Those adapters cost $59 from Mac's. If the cost of replining is scary, how about that adapter? Do you have a different size adapter already? Just use whatever fits your pinion and have the driveshaft turned down to fit.


- alchemy

[Harrison]

Damn, why wasn't I thinking of that? The end of the driveshaft with 10 splines will get cut off. All I need is the 6 spline that fits the pinion with enough material on the end to slip the driveshaft in and weld it up.

Doh!!! JH http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[Zodoff]

Hurray! Finally!! http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[Chopped50Ford]

[ QUOTE ]
I have heard somebody here say they cut their own splines with a cutoff wheel at home. And cutoff wheels can cut some pretty hard stuff.

[/ QUOTE ]

Now thats some kentucky backyard garage machining...w/ a cut off wheel???

Scary http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[redbeard]

I just went through this myself.

one thing no one has mentioned yet it the bearing
in the torque tube.

When you shortened your torque tube you usually just
take it off the big end

the center bearing is no longer in the center of the length.
Vern Tardell told me not to use the solid shaft in this
situation because it will tend to whip around in side the
tube with out the support of the bearing in the middle.

He said if you don't have a 33-34 shaft
make one with heavy wall tubing.
mine has the tranny end welded on
and the coupler welded on the other end

It cost me $80 to have it madeand straightened and balanced.
most driveline shops charge $50 to straighten and balance so
I think it is worth $30.

building cars is not cheap, just have to decide where you want to spend your money.

[Harrison]

I don't think the drive shaft will be long enough to whip around after it is shortened. I was thinking ahead though and shortened the TT on each end to keep the bearing (near) the center.

[Kevin Lee]

On the drive shaft I've got about an inch between the bearing surface on the trans end and the surface where the center bearing used to be - if it didn't whip before it won't now.

Harrison - Again, the surface the bearing rides on in the center of the shaft has a larger diameter than the rest of the shaft...do you plan on shortening the driveshaft at each end too?

redbeard - Did Tardel make your driveshaft? Wanted to cantact him to order a shortened driveshaft but I don't have a fax around.