[Nexus313]

Originally Posted by Eschmacher

Mine has turned out to be the diff apparently... working on a replacement now. I'm also thinking I will get my diff mounts replaced for peace of mind. maybe even get the softest powerflex inserts in addition.

How did you determine it was the diff?

[Eschmacher]

Originally Posted by Nexus313

How did you determine it was the diff?

The shop put it up on the lift and spun the car up to 60, 80, 100 and checked various spots for vibration. The diff was the culprit.

Still hasn't been replaced yet because I've been busy driving for work. But the dealer the shop purchased it from refunded the purchase price - so it's all covered.

[Nexus313]

Originally Posted by Eschmacher

The shop put it up on the lift and spun the car up to 60, 80, 100 and checked various spots for vibration. The diff was the culprit.

Still hasn't been replaced yet because I've been busy driving for work. But the dealer the shop purchased it from refunded the purchase price - so it's all covered.

True, and you have the same symptoms as me? I'm wondering if it's my diff now too or just the mounts..

[Eschmacher]

Originally Posted by Nexus313

True, and you have the same symptoms as me? I'm wondering if it's my diff now too or just the mounts..

Personally I was thinking when I get the diff replaced, I'm going to have my mounts replaced as well. The excess vibration from the bad diff will probably have worn the bushings faster than usual, I assume.

[brigade24]

Originally Posted by jbiswurm

I have the bimmerworld delrin subframe bushings. I just fitted the turner motorsports delrin aluminum diff bushings.

I get a serious amount of noise (to be expected to some degree), but its not really gear whine, its more load based, especially on a poorly rev matched downshift where there a lot of overrun induced driveline stress.

What has your experience been with noises?

I have a relatively new wavetrac unit in as well so i am trying to make sure nothing is broken!

The delrin bushings tightened everything up big time. The increase in noise has been insignificant. I would call it unintrusive. Pain in ass to install...especially the subframe bushings. Dif wasnt too bad.

[jbiswurm]

Originally Posted by brigade24

The delrin bushings tightened everything up big time. The increase in noise has been insignificant. I would call it unintrusive. Pain in ass to install...especially the subframe bushings. Dif wasnt too bad.

Weird. What diff do you have? Maybe the wavetrac is just noisier. Ive never been one to be sensitive to nvh but the gear whine is quite a bit.

Also the solid diff mounts seem to even transmit noise from the exhaust and transmission (rev dependent, not speed dependent) which, while loud, i enjoy quite a bit

[brigade24]

Originally Posted by jbiswurm

Weird. What diff do you have? Maybe the wavetrac is just noisier. Ive never been one to be sensitive to nvh but the gear whine is quite a bit.

Also the solid diff mounts seem to even transmit noise from the exhaust and transmission (rev dependent, not speed dependent) which, while loud, i enjoy quite a bit

I still have the stock differential and exhaust in there. I'm looking at Quaife and Wavetrac...they are both on my list, I hear great things about both and either one is better than what i have now.

I contemplated going with the aluminium bushings but the class i compete in does not allow them.

[jbiswurm]

Originally Posted by brigade24

I still have the stock differential and exhaust in there. I'm looking at Quaife and Wavetrac...they are both on my list, I hear great things about both and either one is better than what i have now.

I contemplated going with the aluminium bushings but the class i compete in does not allow them.

Perhaps that has something to do with it. I love the wavetrac. The power delivery is awesome. The feel, control, and rotation is better by far. Highly recommend. One downside is that i find that TC will still intervene a fair amount as it seems to me that TC does not allow ANY slip where the wavetrac needs a bit of slip before it starts to lock up. So, i need to push the tc button (short push) each time i want to drive spiritedly to give me that little bit of slip in DTC before the electronic nannies kick in. Then the wavetrac cleans things up and i almost never see the TC kick in.

[brigade24]

Originally Posted by jbiswurm

Perhaps that has something to do with it. I love the wavetrac. The power delivery is awesome. The feel, control, and rotation is better by far. Highly recommend. One downside is that i find that TC will still intervene a fair amount as it seems to me that TC does not allow ANY slip where the wavetrac needs a bit of slip before it starts to lock up. So, i need to push the tc button (short push) each time i want to drive spiritedly to give me that little bit of slip in DTC before the electronic nannies kick in. Then the wavetrac cleans things up and i almost never see the TC kick in.

that's one thing with this car that drives me nutts...if you turn off TC, the throttle response is not the same as in Sport+. When i race, i have everything off and which is where i can exploit a wavetrac. but the TC system is very sensitive.

[jbiswurm]

Originally Posted by brigade24

that's one thing with this car that drives me nutts...if you turn off TC, the throttle response is not the same as in Sport+. When i race, i have everything off and which is where i can exploit a wavetrac. but the TC system is very sensitive.

Not turn off... just the short push that gives you DTC which allows a little bit of wheel spin. The wavetrac will lock up before there enough spin to cut power. Thats the same as sport+ mode.

I am 6mt so i always leave the car in comfort but i need a consistent throttle to rev match effectively.

[brigade24]

Originally Posted by jbiswurm

Not turn off... just the short push that gives you DTC which allows a little bit of wheel spin. The wavetrac will lock up before there enough spin to cut power. Thats the same as sport+ mode.

I am 6mt so i always leave the car in comfort but i need a consistent throttle to rev match effectively.

im a 6mt as well. MHD has a linear throttle option which helps make the throttle a bit more consistent...been running it for while and works well.

[jbiswurm]

Originally Posted by brigade24

im a 6mt as well. MHD has a linear throttle option which helps make the throttle a bit more consistent...been running it for while and works well.

Interesting. Im running bm3 and in sport or sport + the slightest tough of the pedal gives you WOT. Its very annoying and unnecessary.

[Watsey]

My car is going to my suspension shop in a couple of weeks time for new SuperPro front arms/bushes and rear subframe bushes. Bearing in mind that the rear subframe has to be lowered so that the bushes can be accessed, how much extra work/time is involved with replacing the diff bushes ?

The front bushes are easy access but I'd appreciate someone letting me know the process for replacing the rear bush, i.e. does the diff housing need to be completely removed from the subframe and the vehicle (disconnect driveshafts) etc.

Thanks.

[Polo08816]

Originally Posted by Watsey

My car is going to my suspension shop in a couple of weeks time for new SuperPro front arms/bushes and rear subframe bushes. Bearing in mind that the rear subframe has to be lowered so that the bushes can be accessed, how much extra work/time is involved with replacing the diff bushes ?

The front bushes are easy access but I'd appreciate someone letting me know the process for replacing the rear bush, i.e. does the diff housing need to be completely removed from the subframe and the vehicle (disconnect driveshafts) etc.

Thanks.

I was browsing Millway's website and came upon their manual for installing rear subframe bushings.

https://www.millway.se/pub/media/wys...19-web-eng.pdf

[Watsey]

Originally Posted by Polo08816

I was browsing Millway's website and came upon their manual for installing rear subframe bushings.

https://www.millway.se/pub/media/wys...19-web-eng.pdf

That's helpful - thanks.

[Eschmacher]

I forgot to update this thread. Nexus313 my diff/diff mounts were fine. My vibration ended up being an axle.

[Polo08816]

Who sells the softest polyurethane rear differential bushing? I'm having a shop replace my rear subframe bushings with solid subframe bushings and I'm planning on replacing the rear differential bushings at the same time.

Either with BMW rear differential bushings or the softest aftermarket polyurethane bushing out there.

[brigade24]

Originally Posted by Polo08816

Who sells the softest polyurethane rear differential bushing? I'm having a shop replace my rear subframe bushings with solid subframe bushings and I'm planning on replacing the rear differential bushings at the same time.

Either with BMW rear differential bushings or the softest aftermarket polyurethane bushing out there.

the purple powerflex bushings are a good quality poly bushing. I wouldn't say they are soft but they are not the stiffest out there.