Combining driveshafts - yay or nay

[jrobie79]

How bad would it be to take the front half of an m42 driveshaft and match it to the rear half of another m42 driveshaft?

I have two, and obviously one has a good rear u-joint, but the front is notchy as hell, on the other it's opposite. Assuming I align the "new" one correctly would this be that bad?

(Not looking to shell out the dough for a reman - that'll be fine when it's parked for winter)

[Farwest92]

I tried that on my 87. No problems until I hit fresh pavement while doing 75. I noticed a slight vibration on the floor. I switched back to the original half with older u-joints and now it's smooth.
Give it try, it might work for you.

[jeffnhiscars]

Drive shafts are balanced as a unit so the odds of 2 unrelated halves spinning smoothly are somewhere between slim and none

[ahlem]

Check to see if you have a local place that balances drive shafts?

[TobyB]

It'll work just fine. It WILL vibrate a bit more- maybe at 45, maybe at 95.
And you can always try reclocking it 180 to see if you get lucky.

Locally, it's like $35 to have one balanced.

hth
t

[Bmwdayz]

It won't be fine. You will be able to drive the car but the vibration from the unbalanced driveshaft will make you crazy. It need's to be balanced

[whodwho]

There is more of an issue when the joints are out of phase

[TobyB]

Having done it a few times, chances are pretty good that if you PHASE it correctly,
it'll work. Pretty well... up to a certain speed.

Shit, I cut 4" out of one once, didn't balance it, and it didn't vibrate under 100...

So try it- worst case is you'll need to have it rebalanced. Which isn't much, compared to
the cost of a new one.

t