Cluncking when changing gear

[discoh908]

I have a big problem and i dont know what the cause of this problem is.
When i change gear in my discovery i get a clunking noise. I have been told maybe it is poly bushes What are these, where are they, how hard are they to change.:(

[floyd fan]

I have a big problem and i dont know what the cause of this problem is.
When i change gear in my discovery i get a clunking noise. I have been told maybe it is poly bushes What are these, where are they, how hard are they to change.:(
May be your UJ's in the prop shaft, was with mine. easy to change and cheap.

[discoh908]

Without sounding too thick whats a UJ. never heard of this.

Cheers

[Rich_P]

A UJ is a universal joint and allows the propshaft to operate at angles. Most RWD or 4WD vehciles use them.

To answer your earlier question, poly bushes are poly(something) bushes, that can be used to replace the standard rubber bushes. There are differant types available, and depending on what you want you can get differant characteristics or you can just stick with what Land Rover originally put onto the vehicle. It is possible the bushes are worn which is allowing the axle to move about slightly. I have a similar case with my 2A, except it uses leaf springs instead of an A-frame arrangement to keep the axle in place. So, when the drive is taken up, as my bushes are worn, there is some play and a fairly loud clunk occurs as the drive is taken up.

Bushes are not the easiest of things to replace (on a Series it can be a nightmare people tell me), and polybushes are supposedly the easiest to fit.

Hope that little bit of info helps you. :)

[Lacy]

There are a multitude of things on Discoveries that can cause clunks in the drive train......the two most common ones are a worn A frame ball joint (quite cheap) and worn gearbox mainshaft (bloody expensive).

Without more info on the clunk or where you think it is coming from, it;s difficult to diagnose.......

If it is the bushes that are worn then replacing with polybushes is the answer......there's loads of 'em......front radius arms, panhard rod, A frame pivots, rear arms, shock mounts.......fitting them is a piece of ****......removing the old ones is a ******.....

[NomadABC]

Just to add to Lacy's comments, get underneath the vehicle with a long screwdriver and try to pry each suspension joint and, more carefully, the steering joints. The only movement should be the flexibility built into each joint by the bushes. There should be no 'rattle' evident.

Also, try turning the propshafts. There will be plenty of play in the gearbox and axles, but there should be no play in the joints themselves. They should not move up/down or side to side. Finally, check the rear rubber donut between the proshaft and diff. They can disnitegrate.

Get back to us.

[discoh908]

Thanks will take a look

[discoh908]

There are a multitude of things on Discoveries that can cause clunks in the drive train......the two most common ones are a worn A frame ball joint (quite cheap) and worn gearbox mainshaft (bloody expensive).

Without more info on the clunk or where you think it is coming from, it;s difficult to diagnose.......

If it is the bushes that are worn then replacing with polybushes is the answer......there's loads of 'em......front radius arms, panhard rod, A frame pivots, rear arms, shock mounts.......fitting them is a piece of ****......removing the old ones is a ******.....
It sounds like the clunk comes from the rear of the disco, the clunk occurs when i let the clutch out or slow down and pull away without selecting a lower gear.

cheers

[abyssdj]

id say its your UJ's discoh908. get some old clothes on, scramble underneath, and have a good yank on the prop shafts. if they seem to move (not rotate, but move) then one or more of your uj's are probably ******ed up.

its the part on each end of the prop shaft that connects it to the gearbox, etc. had to explain that for ya, as i dont really think the description of what it actually does really helped you much ;)

our defender had the same symptoms, accompanied by a mega vibration at about 50mph. changed the rear UJ, all is well. still a bit of a clunk, but its not half as bad