just a thought... I had a strange vibration in a car I was working on once that turned out to be a broken motor mount after everyone else had changed, balanced and rotated the tires about three times over before they turned it over to me (the idiot who takes ANY job that nobody else wants). After replacing the motor mount it was smooth as silk though.

-Should be with triple-balanced and rotated brand new tires!!! hahaha

 

Have you had an alignment done? Where is the vibration... front end? steering wheel?

Eric

 

Did they check for a tread separation?
Is your roto-flex cracked? Front drive shaft wont shake at the speed.
How often have you been greasing your u-joints?

 

75Mph in the land rover world is the speed of light. That shaking is the rig trying to hold itself together while being being pulled apart by the forces of the universe.

Ludicrus speed GO!!!

 

@SDinDS- I had an alignment done about four months ago when I replaced the tires.

@ Disco Mike- Ill check the what is the "roto-flex" and in the past I was no greasing the u-joints at all which I learned the hard way by having to replace the front drive shaft. With the new one I plan to do it every 3,000 miles, is that often enough?

@sloppyjoe- I know 75mph is fast for a landrover but I drive on the interstate a lot a the 75-80mph range is easy to creep into, fortunately this shaking has me keeping it to 70mph because the car just doesn't seem safe with that shake.

 

The Rotoflex is the rubber disc that goes at the diff. end of the rear driveshaft. Basically takes the place of a u-joint. I think there is a kit available to replace the rotoflex with a standard u-joint, but it's not completely neccessary. Just take a look where the rear driveshaft connects to the rear diff. and check for cracking or shredding in the rubber.

3,000 miles is plenty good enough, I think they recommend greasing it every 3 months or 5,000 miles or something like that. I've heard most people do it at every oil change. Just make sure you get new, fresh grease out of ALL FOUR caps on each u-joint. If you don't there is a chance that you have grease baked in there and it's blocking the flow of the new grease. If this happens you should tap the cap on the opposite side of the joint and try to get grease through it again, if this doesn't work you should probably plan to rebuild soon, without new lubricant in there it will just get worse and worse until it fails.

 

For what its worth Sloppyjoe is right -- my rover NEVER goes over 70 for fear of too many expensive parts vibrating off...

Two simple fixes for a lot of problems are (1) Slowing down and (2) turning up the radio...