Drive shaft problem W/pictures

[Stone17]

What wrong with my Dynotech 4" driveshaft?
My car vibrates at around 70-75 MPH but goes away at 80 MPH.

Two years ago I broke the rear differential mount and the vibration started after that.

Pulled the shaft today and seen this. Look like the thing is hitting the shaft Its on both sides.
Rear of the shaft. Its going to a drive shaft shop monday.

 

[driller]

Is that the u-joint ends hitting the driveshaft???

 

[95blklsc]

It shouldn't be rotating off axis that much. Something is WAY off.

 

[Stone17]

Is that the u-joint ends hitting the driveshaft???

It shouldn't be rotating off axis that much. Something is WAY off.

Yep. That connects to the pumpkin. Dont know if this helps. But all 4 bolts where loose.

 

[billcu]

That probably happened when you broke the mount, and it tweaked the driveshaft?

How loose were the bolts?

 

[Stone17]

How loose were the bolts?

I could loosen the bolts with my finger.
After removing one bolt the whole drive shaft was loose.

 

[Stone17]

That probably happened when you broke the mount, and it tweaked the driveshaft?

Yep. I hope the drive shaft is out of balance.

 

[beerdog]

Take it to a shop that balances drive shafts and have it checked. They might be able to fix it if it is damaged.

 

[Roadboss]

Yep time for some new parts and alignment and balance checks.

 

[J]

Why didn't you just tighten the bolts and recheck it? Loose bolts=Vibrations at speed.

 

[Stone17]

Why didn't you just tighten the bolts and recheck it? Loose bolts=Vibrations at speed.

I was thinking about that but did not want to put the car back together.
Took me 30 min to remove the drive shaft.

Right now it's in the back of the Caddy. Im going to drop it off at a shop today.

 

[Stone17]

$173 to get it all fixed up. Balance and new u joints

 

[SCTBIRD1173]

OUCH! Well at least I know what I have to look forward to... I need to have my 98's driveshaft balanced before Carlisle.

 

[Stone17]

OUCH! Well at least I know what I have to look forward to... I need to have my 98's driveshaft balanced before Carlisle.

It would be cheap for you to get a 93 Mark VIII Drive shaft at a junkyard.

 

[SCTBIRD1173]

Thanks! yeah it does seem that way huh...

I really didn't want to do anything crazy here since I haven't decided if I'm keeping this thing auto or not. I plan on getting a Dynotech when all is said and done. I figured a quick balance to hold me over but I had no idea they were so expensive.

 

[budpytko]

Get another estimate....

Owning a Mark VIII is NOT cheap. But owning ANY 14-15 year old car ain't cheap!

 

[beerdog]

That is not out of line. Probably $40-50 to balance. Maybe $50 to install new ujoints. What else do they need to do to it? You will spend that much buying a used 93 1 piece, new ujoints, and balancing. a 4" dynomax is better than a 93 shaft. Isn't that a $450 drive shaft?

 

[svtlincoln]

Get another estimate....

Owning a Mark VIII is NOT cheap. But owning ANY 14-15 year old car ain't cheap!

Nope but it's cheaper than a $500 a month car payment.

 

[Stone17]

Nope but it's cheaper than a $500 a month car payment.

My car payment is $445

 

[SCTBIRD1173]

That is not out of line. Probably $40-50 to balance. Maybe $50 to install new ujoints. What else do they need to do to it? You will spend that much buying a used 93 1 piece, new ujoints, and balancing. a 4" dynomax is better than a 93 shaft. Isn't that a $450 drive shaft?

I was getting quoted $100 most places just to balance it with no guarantee it would balance. I've never had a driveshaft balanced before so I have no idea how much it should cost. If it needs u-joints I'll do that myself, I rebuilt the one in my SC about 12 years ago and never had a problem.