Just replaced my worn out/leaking diff mount bushes with Super Pro urethane ones. Marked the diff and drive shaft flanges so they are bolted back on properly.
Problem is I now have harsh vibration (like driveshaft imbalance) that shake the whole car from 210kmh (130mph) I never had this vibration with the stock diff mount bushes even when they were stuffed. Anyone had this same problem??

 

Interesting. I've bought those same bushes awaiting them to get put on very shortly but may reconsider if it vibrates. I have the complete super pro bushes installed on all my rear suspension components, i.e control arms, trailing etc and haven't had a problem with vibration.

 

there is a thread somewere that people were sharing there experience with delrin or how ever you spell it and super pro.. i have the super pro diff bushings awaiting to be installed but iv heard good things about it and no much vibration from them

 

I installed superpro diff bushings and I haven't experienced any vibrating or shaking at any speeds including 130mph+... is it possible that other bushes are gone, or perhaps pillowballs... ?

 

Other ones havent been touched pretty sure they are good. Only diff mount bushes and now vibrates badly. No prob with lower speeds. Maybe I'll just get the d/shaft balanced mybe the vibrations were there before, stock bushes just did a great job absorbing them being softer than super pros.

 

Balancing the driveshaft is a good idea indeed.

Dave

 

How many kms do you have on the car.

I have mine installed and loving it. Although I have not taken the car at those speeds but no vibration. If anything It made the ride less harsh since I replaced all the bushings that has 186k on it.

 

I think I might have found the solution to another problem on my car.

I don't think I balanced the driveshaft or anything of that nature when I put the engine and tranny back in last time around.

 

I installed a set of superpro diff bushings on my car a few months ago. I felt that they were much better than worn out stock bushings. There was definitely more vibration under high load/high speeds, but nothing too harsh. After a few months ~3000 miles, the vibrations have reduced.

Kevin

 

I have taken my driveshaft off 20-30 times (sad but true...) and after the first or second time I stopped paying attention to how it was lined up. I have never heard any type of noise or vibration from it.

Do I:

1) Have an amazingly balanced drive shaft
2) Have incredible luck.
3) Drive too slow. (Peak on my Power Meter is 143 mph main straight at VIR)

Or is this a non-issue?

 

I have the super pro diff bushings and have had no issue with vibrations. I however have not had the car above 130 since they where installed.

 

Cars only done 80,000km. Cars driven hard when its used (once or twice a week)
mostly on weekends when not many cars on the road so it can get a bit of exercise.
Got a Toyota BB daily driver gets more looks than the FD believe it or not
Some thinks its cute some thinks its butt ugly

 

I had the solid Jim Lab bushings and never experienced this kind of problem. This could easily be your tires. The stiff bushings will transmit more drive train vibrations in the cabin if something is out of balance. You can easily check by jacking up the rear and running through the gears with the tires on and off. Then you can remove the drive shaft and do the same thing to check for engine & tranny vibrations. If your engine was rebuilt with a different set of rotors that are not balanced with the original counter weights, you will get engine vibrations. Mazda drills holes in every counter weight to perfectly balance every rotating assembly.