Forest Green

I've just recently fitted a Whiteline front of rear diff lock kit to my MY99 impreza.

Since driving it at motorway speeds, there is a vibration that shakes the whole car and doesn't seem to go away if i increase my speed.

Any suggestion as to the cause of this? As it doesn't feel normal / safe.

Thanks

Chris

911

That is certainly NOT my experience after fitting the same kit 4 years ago.
My 3'' decat makes more noise/vibration.

Obvious, but it is all done up tight?

Find Geo on suspension section (cusco kid) as he is the Whiteline dealer for the UK and will help you out.

Forest Green

Thanks for the reply.

I'm sure it is done up tight (I got the local Garage / Jap specialist to do it).

It's a loud vibration that appears at about 70mph and does not want to go!
I have done a search for this but can only find suggestions for wheel balancing / buckling / tyre flatspots. It feels like propshaft vibration, which is another point that was mentioned.

I'll contact Geo (Cusco Kid) and see what he says.

Thanks again

911

Just a thought. The clearance of the exhaust to the rear subframe can be tight, especially if you have a 3'' through system. It can get very close to the frame which is suported by the new poly bushes you have installed.

When the engine is working hard, it will twist on it's engine mounts, and that can bring the exhaust JUST into contact with the rear frame.

The size of the new bushes 'maybe' has closed the gap enough to have this happen. Get under and have a good look. you really need about 10mm or more clearance between the rear diff frame and the exhaust.

Such contact will be very audible.

Forest Green

I'll have a look at it when the weather gets a little better (Fair weather mechanic! )

I took the car out for another drive and it now sound's like more of a pulsating vibration rather than the constant vibration that i had before.

Forgot to mention that my car has a Ninja de-cat down-pipe, Magnex centre section and Hayward and Scott backbox.

Chris

911

I would still check everything for clearance.
Check also the run of the handbrake cables incase they are trapped somewhere.