[1968 cougar GT ]
I replaced my U-joints and seals… during my test drive i got a strong vibration even at low speed, I’m not sure I’m the one that dented the driveshaft so maybe I didn’t set the preload right at the yoke…
But still, this driveshaft seems junk isn’t it ?
tail shaft bushing is bad most likely allowing movement of tail piece in tail of transmission
I think it’s junk. The good news is that a local driveshaft shop can generally build a new fully balanced unit for less than you’d expect.
I see ! I only got a new seal but no bushing so I didn’t replace that… maybe i should’ve
I live in France so it’s a bit harder… but i’ll look into that !
try heavy duty truck shops
Like blue68cat said likely the tube has to be replaced the other parts are still usable.
you mean the ends and the U-joints?
Another option for not too bad $ is full new reproductions
https://www.deadnutson.com/1967-1971-cougar-parts/
get ahold of Jack he will help you .I had one done for my 70 CJ w/ a TKX!
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Correct a drive shaft shop will only replace what needs to be replaced. In this case the tube.
I took an appointment to a Shop.
Then again, I also replaced the pinion seal and did the preload by marking the nut and measuring threads… I believe if done incorrectly like I did the preload could also cause vibrations and grinding noise?
I’m not sure, but it could be, as there is a “crush washer” & torque spec for doing that job.
Your shop will be able to diag. quickly. Im thinking its gotta be one end or the other.
I just don’t think your “dent” is a issue.
If the weight next to it was gone, yes it needs a shop or replaced
Yeah, though the marks I made do lineup I still have a tiny bit of play forward/backward at the yoke so maybe it just needs another turn at the nut. Ill give it a try and check the drag with a torque wrench
did you have a vibration before the u joints and seals?
No= yoke not tight
Yes+ probably driveshaft
I did have a small vibration only at highway speed. Now its like rubbing noise and strong vibration even when leaving at the stop sign
Couple things Try disconnecting driveshaft from the rear axle and rotating it (mark it first so you don’t put in same location).
I would have the driveshaft rebalanced. and last check all the angles (motor, transmission and rear end) pinon. they have apps where you can use your phone. The app I use on my (iphone) is called TREMEC they offer a few diffrent calculators.