MGTF PolyBush compliance bushes

I'm not sure how worn the bush is but it does have the tell tale clunk that the rubber ring around the top has worn to the point the trailing arm can hit the bushing assembly causing a clunk and also a rattle when setting off. It has been mentioned that you can bodge this with bits of plastic or cutting and making a rubber shim but I'd rather replace bushing and the ring as the car has about 130k miles so its most likely work as well.

My main reason for wanting to replace them is the clunking coming from the rear which is mainly on the left side but also occasionally on the right, having read online it would appear to be because the rubber on the top of the bushing has worn down to the point the metal of the trailing arm hots the bushing assembly.

A bush that makes clunky noises can’t be good, after all the point of bushes is to allow movement and compliance without banging and clunking!

my thoughts too, its only on certain bumps like speed bumps that seem to cause it.

At least from what I can see from the design of the bush it seems more of an issue of the suspension design. As all of the lateral arms allow rotation in more than one direction, the job of constraining the rear Hub's rotation around that axis is also one by the trailing arm, and as the arm is only fixed at on place this also doesn't fully constrain it. that is in my mind why there is a flat plate on the trailing arm where it sits on the bush to stop it from 'complying' left and right as it were. this naturally over time wears down the rubber it sits on till it reaches the metal.

Are you sure the bush is the cause of the noise? It maybe that although the bush looks suspect and that’s what you found when you looked, that’s what you found that didn’t look right, but the cause of the actual noise is something else? Like a shock absorber perhaps?

I’m a F’er not a TF’er so I’m not all that familiar with the TF suspension, so I’m only really guessing 

I have been looking into it for a few months and I have changed the rose joint style bushes on the upper arms and shocks and the ball joints on the hubs. I cant find it at he moment but there was a youtube video that detailed the same noise in which he put a rubber disc on top of the bush that fixed the issue, so I am considering removing a trailing arm to ensure that is whats causing it, but that's quite a big job in itself

EDIT: link to suspension diagram https://www.16vminiclub.com/forum/general-public-area/rover-chat/20901-anyone-used-a-mgtf-frame-including-suspension

Don’t forget the small cross-bar that sits on top of the compliance bush. As far as I am aware it is prevented from metal to metal contact by a rubber/polymer additional component that is like a thick washer sitting on top of the bush that is pressed into the metalwork of the compliance bush assembly.
Could it be that polymer washer that is missing/damaged?

I did a complete front and rear suspension rebuild just over a year ago, the subframes were replaced with galvanised ones and every wheel bearing and ball joint bar the rear track control ones. Poly bushes were fitted all round with the idea of making it maintenance free for a few years. I think that replacing the rear compliance bushes are down to if they are worn out, but it is also down to where and how you drive. We drive over Exmoor quite a lot, especially from now until Easter while the roads are very quiet. At times we do push the car to its limit and that is where the polybushes all round and the big brake discs come into their own. If you are just out for a normal drive then I wouldn’t bother, the ride is much firmer, not uncomfortable but firmer. 

I believe that rubber part on top of the compliance bush is what has worn through allowing for metal to metal contact which causes the noise.

EDIT: found the video here you can clearly see how it wears through

That certainly looks like a solution to the compliance problem on a TF. The only comment I would make would be the material he used to make the doughnut didn't look like a "permanent" fix.
I would probably use a harder plastic material rather than rubber. As I did when I fixed my compliance bush issue with the F.

2mm thick ABS plastic.
 
I fitted these over 10 years ago and they are still in A1 condition. They are 60-61mm outside diameter;25mm internal diameter. I used a number of them as shims to take up the worn space on the compliance bush, which is the issue on the F.

I see that the TF polybush kit uses a separate poly doughnut
 

thats correct and they do look to be quite thick on the polybush ones, given my schedule Ill likely be looking at doing something in November, if I do end up replacing them with polybushes I will try to document it for a how to guide.