vibration......

[storm9c1]

Oh yeah going from 3.08 to 4.10. That does increase driveshaft speed significantly, which turns a small imbalance into a big one. I've been through that before. I've even had it going from 3.08 to 3.42. You may need to get the thing rebalanced if re-phasing it does not make a difference. Pretty common for doing gear changes on old iron. I've had it done at least 3 times in the past several years on different vehicles. There is a truck chassis shop about 20 minutes away from me. They can rebalance a drive shaft in about an hour for under $50. They can do car and truck drive shafts. Look for one near you. Might not be as big of a deal as it sounds to get done.

[cableguy0]

Originally Posted by storm9c1

Oh yeah going from 3.08 to 4.10. That does increase driveshaft speed significantly, which turns a small imbalance into a big one. I've been through that before. I've even had it going from 3.08 to 3.42. You may need to get the thing rebalanced if re-phasing it does not make a difference. Pretty common for doing gear changes on old iron. I've had it done at least 3 times in the past several years on different vehicles. There is a truck chassis shop about 20 minutes away from me. They can rebalance a drive shaft in about an hour for under $50. They can do car and truck drive shafts. Look for one near you. Might not be as big of a deal as it sounds to get done.

Very good point. Definitely got him going in the right direction.

Find a good driveshaft shop. Having it balanced isn't a bad idea regardless if that is the cause of your problem. Its not very expensive and making sure the driveshaft is spinning true is insurance for the rest of the drivetrain.