Can somebody help?
I have been pulling my hair out with a shimmy or vibration that starts at 62 mph.
I have all new tires that are under 5 on the road force. I've had the same vibration with the old tires also, so I am thinking now it can't be the tires.

It has been lowered in the back 3 inches and the front 2 1/2 inches, could this be a problem with pinion angle, would that cause a vibration at 62?
I have been waiting for ayrton to finish the bump steer kits but I don't think it is that.

It feels like the whole truck is shaking.

Any suggestions appreciated

 

Is there any shake in the steering wheel? If not then it is most likely pinion angle. Mine did the same when I lowered the rear. However my shake was around 40 or so, but since it sounds like you went lower than me, it would make sense that the shake or vibration would be at a different speed.

Another question is how did the vibration start when you lowered it? If it didn't then maybe you are looking at a drive shaft problem instead.

 

I am pretty sure when you lower that much in the rear you should have added some new (different) pinion shims...

 

The drive shaft angle is pretty close to straight. Is this not the best thing or should the drive shaft have an upward angle from the pinion?

Thanks guys

 

Yes the drive shaft should angle up from the pinion. If you do a search you can find what the stock angle should be. I remember some pretty good diagrams that I think Tim Skelton posted(not sure though). I just did my own search and found that you had posted back in october with questions about pinion angle. If this is when the problem started you need to fix it now.

It is quite possible that if the vibration is getting worse you would then need to not only correct the pinion but possible have the rear end rebuilt due to a bad bearing or new u-joints. The technical term is called binding I believe. Good luck but get it fixed now.

 

Thanks for the info mcgill.

I hope I haven't ruined anything.

Chris