Mike..... only problem I could see with this idea is that polyurethane is a hard substance that has no flex at all in it. Ideal for bushes in control arms and such where there is no requirement for the bearing to flex. With a prop shaft the angle of the shaft relative to the floor of the car to which the bearing is mounted is constantly variable by a small amount of degrees, depending upon just how high the car is sitting on its suspension at the time of measurement.
The reason you are getting the 'knock' on acceleration is most likely down to the shift in weight distribution from the front to the rear which is common in rear wheel drive cars, particularly older ones that have less sophisticated suspension systems such as ours do. This is why you have the splined shaft coupling on the gearbox end, as the more parallel the shaft becomes with the floor of the car the further forward the coupling needs to move so as to accommodate the extra length in the shaft. I fitted Spax adjustable shocks on my car's rear end and set them up for a stiff ride which probably explains why I'm not getting the knock when I hoof it.
If you have them try adjusting them so as to stiffen the rear end suspension which should have the effect of minimising prop' shaft float and see if it improves the situation. If you don't have them consider buying some as they do improve the overall handling of the car significantly for relatively little money.
Maybe you're right. Adjustable rear shocks have been on my list for a while: Never seem to have the time! My rear passenger once complained it was like being in a boat!
Last time I looked I found some for a Hunter.
Have you a part number/supplier you could recommend?
TBH I can't remember as to where I bought them now Mike. It was several years ago maybe a couple of years before I took the car for it's first MOT. They cost me about £120 the pair and although the original ones weren't leaking, they were heavily corroded, so it was a no brainer really.
The first time I drove it I realised I'd set them up way too stiff, it was almost as if the car was riding on the rear axle with no suspension at all. So I softened them every time I took it out by 1/2 a turn at a time till I found the ideal compromise.
Hunter ones should fit AFAIA if they are the only ones you can get your hands on as the Rapier is almost a forgotten car as far as aftermarket support goes these days. The only possible exception being Speedyspares maybe.
Don't see any reason as to why not cos everything else in the way of suspension appears to be interchangeable. It was about 5 - 6 years ago I guess since I bought mine, so was surprised to see they had gone up that much.
Propshaft support
Posted - 09 Mar 2020 : 09:20:08
