Driveline Noise after Lift - Disscussion

[VR4-Quest]

Obviously there are several types of driveline noises associated with low tire pressures, defective axles, etc. but there seems to be a common issues with noise after lifting. I know for sure this to be the case as mine made noise on the test drive after installing the OME912's, and was fine before. We need to put our heads togther and figure this one out!

Again, Im talking specifically about a driveline derived noise, after lifting the VX with OME912s or equivalent, happens most notably when letting off the throttle at highway speeds (above 60 mph). Its accompanied by a grinding noise and vibration that can even be felt through the floor (fairly severe). There is also some noticable increase in vibration at lower speeds (around 40 mph).

I have lubed the U-joints and drive shaft, and check the level of all driveline fluids and there was no difference.
I have not yet changed fluids nor had the front bearing repacked lately.
I have maintained the factory rake (front 1" or more lower than rear) and the noise still exists.

Please add your comments, solutions if any, and feedback concerning this so we can determine the root cause!

[Joe_Black]

Take a look using the search feature here as NivD did the 912 lift and ball-joint flip a few years ago and immediately had driveline noise. Don't recall the remedy but it was pretty simple and should be in his posts.

[VR4-Quest]

That user name could not be found?

[psychos2]

when you raise the rear suspension you are actually pushing the axle to one side. there is a bar that links the axle to the frame. i do not know by how much. but the added angle to the driveshaft from the lift and the angle do to the axle being pushed over could be the cause. does anyone know what the max angle is for the driveshaft? shawn

[psychos2]

also niv_d is the users name. shawn

[mbeach]

Hmm... Good point (about the axle shift).

This doesn't appear to be something that has been addressed with the 912 lift before.
An adjustable track bar would fix this problem easily.

Now, is the noise atributable to the laterally shifted axle?

[VR4-Quest]

I notice more of an axle shift (wheel/tire on passenger side sticks out more) when I only had the 1" polyspacer, know with the 912's, it seems better center. I think so becuase at the original ride height, I think the bar is angled up, the 1 inch lift made it level, thus shifting it more, now with 912 its angled down the same amount it was angled up originally.......I think.......... I need to look into this more. The thing is, the drive shaft angle (up - down) doesnt seem that severe at all with the lift.