drive shaft question

[markahurley]

can a heavy load (weighing down rear shocks) affect the drive shaft? i.e. cause it to become unbalanced? i've noticed the same vibration in both of my last two fords, and am wondering if it's because of the trailer weight. what do you guys think?

[seabee1]

i would not think so ,unless it was drastically over loaded .

[mag360]

Yes. When loaded down the u-joint angles will be affected and this can cause vibration (especially at startup) for a truck with a two piece driveshaft while loaded. This can wear out your u-joints faster than normal. It wouldn't "unbalance" the shaft itself but can cause that kind of feel while loaded and, if the joint/joints are bad you would get vibration unloaded as well.

[GravelyNut]

Yes. When loaded down the u-joint angles will be affected and this can cause vibration (especially at startup) for a truck with a two piece driveshaft while loaded. This can wear out your u-joints faster than normal. It wouldn't "unbalance" the shaft itself but can cause that kind of feel while loaded and, if the joint/joints are bad you would get vibration unloaded as well.

Correct. A driveshaft also needs to be run at atleast a 3° angle to function right. Not in a totally straight line as most would think.

[kaferhaus]

The rear suspension would have to be nearly bottomed out for you to realize any adverse effects on the driveshaft.

If that's the case you should know better than to operate your truck under those conditions anyway.

The actual weight of the trailer would have no effect whatever. Obviously tongue weight is what causes your rear end to squat.

Ever think maybe the trailer is the source of the vibration????