MGTF PolyBush compliance bushes

I looked into doing this last year when upgrading my suspension. There is not a lot of information regarding changing these bushes on this site as well as others. I eventually got the impression that it was both a difficult job and not that essential. I was advised by VHS that while upgrading the front suspension with poly is a good idea, the rear was not so necessary. Unless your compliance bushes are really worn and require replacement, I would leave them alone. 

I would tend to agree with that. Aas stated I considered doing this job for various reasons and accepting various recommendations from people who had worked on my car.
I obtained some spare bushes (metalwork) and cut out the rubber bits . Those needed more than a gentle tap to get them moving. I made a timber support to hold the one with the angled base so it could be supported in line with the axis of the press - very useful apparently as stated by the workshop that did the job.
The workshop had one heck of a job in getting the bolt out of one of the bushes - don’t know which one. As stated one of the nuts used to support the subframe had to be replaced as the bolt sheared off (not unusual apparently).
As observed by Goodwood the new bushes made little if any difference that I could detect.

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