Driveshaft spline worn

[topchop]

Ref previous post for '47 sedan:

https://www.fordbarn.com/forum/showth...ghlight=pinion

Finishing up the rear end rebuild and thought I was done.
However, I have a problem with worn driveshaft spline. Discovered quite a bit of "slop". Pin was not loose and hard to press out. Coupler appears good, as both end of the 6-spline fits nice on the new pinion shaft.

What to do, if anything, short of replacing the driveshaft?

Anyone repro driveshafts?

Thanks for any insight.

Jim

[cas3]

if the front bearing surface is good, i'd run it

[Kube]

Originally Posted by topchop

Ref previous post for '47 sedan:

https://www.fordbarn.com/forum/showth...ghlight=pinion

Finishing up the rear end rebuild and thought I was done.
However, I have a problem with worn driveshaft spline. Discovered quite a bit of "slop". Pin was not loose and hard to press out. Coupler appears good, as both end of the 6-spline fits nice on the new pinion shaft.

What to do, if anything, short of replacing the driveshaft?

Anyone repro driveshafts?

Thanks for any insight.

Jim

There is NO way I'd run that shaft. It certainly is not going to "get better" and will as a matter of fact get more rapidly than in the past. Nope, this is a failure in the (near) future just waiting to happen.
For the cost of replacing ii and the labor involve now vs. later... swap it NOW.

I don't believe anyone repops these shafts. However, good (condition) original shafts are fairly readily available.

[rheltzel]

Continued use will also wreck the pinion shaft. I ruined an otherwise good 3.54 gear set that way. Don't use it.

[john in illinois]

I would suggest rechecking the coupler also. It is difficult to visually check the splines inside. I use the bent end of a scriber to check for a step along the splines. It could feel tight on new splines and still be worn.

John

[topchop]

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The "front" spline is perfect, and I have a new u-joint for that.
The coupler is perfect on the side that goes on the new pinion shaft.
The other side (of coupler) that fits on the worn spline is the one that's worn.

Someone suggested having material welded on the spline to build it up.
I can then machine the spline to fit.

Is this a viable fix?
What are my risks (other than getting a good fit)?

[JSeery]

That would ne a very difficult weld and machine job. Your best bet would be to find a new shaft. If you want to attempt to save this one you could try welding the coupler to the driveshaft.

[V8COOPMAN]

Originally Posted by topchop

I can then machine the spline to fit.

YOU can really machine that spline PROPERLY? It would seem that anyone with the technical knowledge involved, along with the proper equipment to re-machine repaired splines, as well as the ability to properly re-heat-treat that splined forging, would already know the righteous answer for a lasting fix. DD

[JSeery]

I resplined the axles on my rear end. I was difficult, time consuming and required expensive equipment! And that was simple compared to attempting to weld up the driveshaft splines and machine them.

[klicker]

What Kube said. Go find another shaft! They're out there.

[Kube]

Originally Posted by topchop

The "front" spline is perfect, and I have a new u-joint for that.
The coupler is perfect on the side that goes on the new pinion shaft.
The other side (of coupler) that fits on the worn spline is the one that's worn.

Someone suggested having material welded on the spline to build it up.
I can then machine the spline to fit.

Is this a viable fix?
What are my risks (other than getting a good fit)?

Placing a new spline in to that shaft requires a professional with the proper tooling to do it. If you don't have the skills nor the equipment and would need to pay someone that does, you will have far more invested in this worn out shaft than the cost of a replacement.
If you want me to look through my parts and see if I have one, let me know. I don't mess much with the post '40 Fords so if I have one, I'll part with it.

[cas3]

so, the coupler is worn, not the shaft?

[Kube]

Originally Posted by cas3

so, the coupler is worn, not the shaft?

See post #1

[V8COOPMAN]

See post #6.

Story is ever-changing......... inconsistent at best! DD

[Kerk]

Look up Brookline Machine. They have several branches and I believe at least one in N.Y. I know they are in N.Andover,Ma. Boston, Ma and I think R.I. and maybe Ct. Have used for our F- 8 w 5speed Pumper with a 337 as well as a 32 shorting job and spline chg. from 10 to 6 . Always satisified. Just a suggestion.

[richard crow]

bring it to a drive shaft shop have them weld a new coupling to the shaft then check for alliment & balance . with onley one end welded you can install shaft using the pin

[Terry,OH]

Get another drive shaft and coupler that are in good shape. I will send you a PM.

[Planojc]

I agree with Richard Crow. A drive shaft shop can weld a new coupler on it. I had to change the coupler on my 35 when I went to a 3.54.