Powerflex differential bushings

[caacosta]

Originally Posted by hC1001

Yes purple. Didnt really push the car as i need an alignment. It feels like stock so far.

Stock? I was hoping to hear an improvement over stock. May have to either go turner or pf black

[hC1001]

Originally Posted by caacosta

Stock? I was hoping to hear an improvement over stock. May have to either go turner or pf black

Yes. Just like when the car is brand new. The purple pf bushings are only slightly stiffer than the stock bushings but poly is much more durable. What type of improvement are you trying to achieve? The harder the bushing, the more solid the rear end should feel at the cost of NVH. If you want stock NVH but a more solid rearend, i would do turner bracket and pf purple like RSXDC5 did. I would assume going with pf black is as stiff or stiffer than going with pf purple and turner bracket but dont quote me on it.

[rborane]

From powerflex-

"The OE bushings are typically about 50-55A Shore, so yes the street versions are about 20-25% stiffer than the OE parts.

The Black series bushings can certainly cause some additional vibration and harshness especially with differential bushings."

I have the turner dual bracket and street powerflex going in this week.

[rborane]

Bumping this back up as I've had the Powerflex Street (purple) diff bushings (front and rear position) installed for a week, with the turner dual rear mount plate. The rear of the car feels a lot better, DCT shifts are crisper and smoother, and throttle is more direct.

One thing I am noticing is a loud clunk that is audible when I am driving and lightly tap the gas pedal on and off with just enough pressure to send a bit of load, but not enough pressure to where the car surges forward. I found that I can replicate it easy in 3rd around 25mph and 5th at 45 mph. Any faster and the clunk noise is less audible. It is less audible in efficient (auto mode as well, but still there).

Shop reviewed everything and all looks good, trans mounts look good, car is in good shape. What can the noise be? I went with the street bushings to minimize NVH, but could they still be the cause or anyone have any idea what the clunk noise is when i go on and off the pedal lightly?

[elite53]

Originally Posted by rborane

Bumping this back up as I've had the Powerflex Street (purple) diff bushings (front and rear position) installed for a week, with the turner dual rear mount plate. The rear of the car feels a lot better, DCT shifts are crisper and smoother, and throttle is more direct.

One thing I am noticing is a loud clunk that is audible when I am driving and lightly tap the gas pedal on and off with just enough pressure to send a bit of load, but not enough pressure to where the car surges forward. I found that I can replicate it easy in 3rd around 25mph and 5th at 45 mph. Any faster and the clunk noise is less audible. It is less audible in efficient (auto mode as well, but still there).

Shop reviewed everything and all looks good, trans mounts look good, car is in good shape. What can the noise be? I went with the street bushings to minimize NVH, but could they still be the cause or anyone have any idea what the clunk noise is when i go on and off the pedal lightly?

I read a post a while back where a guy was describing something similar and he said it turned out to be the large nut that connects the driveshaft to the diff. Apparently if it's not torqued properly that it will cause a clunking in the rear end.

[rborane]

Originally Posted by elite53

I read a post a while back where a guy was describing something similar and he said it turned out to be the large nut that connects the driveshaft to the diff. Apparently if it's not torqued properly that it will cause a clunking in the rear end.

Any way you remember where that was? That would be a huge help. The car drives fine, but the noise definitely is not normal and I would love to fix it.

[rborane]

@hC1001 is your car DCT? Can you read my post above and tell me if you notice anything similar on your car with the powerflex street bushings?

[elite53]

Originally Posted by rborane

Any way you remember where that was? That would be a huge help. The car drives fine, but the noise definitely is not normal and I would love to fix it.

I wish I could remember where I saw it. I'm pretty sure it was on this forum tho. Sorry.

[hC1001]

Originally Posted by rborane

@hC1001 is your car DCT? Can you read my post above and tell me if you notice anything similar on your car with the powerflex street bushings?

No, its a manual and i dont have any clunking. I replaced the bushings myself and i specifically didnt want to remove the driveshaft nut or the half shafts from the diff. BMW really emphasized the importance of correctly installing the driveshaft back by replacing the driveshaft nut and using specific threadlocker and also giving it a curing time before using the car again. Theres nothing difficult about it tho, just have to follow the instructions.

[FlyingLow78]

What kind of driving are you guys doing that’s causing the stock bushing to fail? Hard launches? Drag racing? Road racing? Just curious, since it appears to be a lot of work to replace it.

[RSXDC5]

Originally Posted by FlyingLow78

What kind of driving are you guys doing that’s causing the stock bushing to fail? Hard launches? Drag racing? Road racing? Just curious, since it appears to be a lot of work to replace it.

It depends on if you have the v1 or v2 oem rear diff bushing. V1 is fluid filled and prone to cracking by 20k miles even, v2 is poly

[Andrew30azs]

Originally Posted by rborane

Bumping this back up as I've had the Powerflex Street (purple) diff bushings (front and rear position) installed for a week, with the turner dual rear mount plate. The rear of the car feels a lot better, DCT shifts are crisper and smoother, and throttle is more direct.

One thing I am noticing is a loud clunk that is audible when I am driving and lightly tap the gas pedal on and off with just enough pressure to send a bit of load, but not enough pressure to where the car surges forward. I found that I can replicate it easy in 3rd around 25mph and 5th at 45 mph. Any faster and the clunk noise is less audible. It is less audible in efficient (auto mode as well, but still there).

Shop reviewed everything and all looks good, trans mounts look good, car is in good shape. What can the noise be? I went with the street bushings to minimize NVH, but could they still be the cause or anyone have any idea what the clunk noise is when i go on and off the pedal lightly?

I had them . The Purple ones And also i had on low speed clunking noise from my dct. Why because that bushings are less soften then The oem ones. I was driving with clunking noise for couple months Then i decided to get back for oem
And most clunking goes away but still have something

[MT0Y]

Noob question.. process of elimination for my issue.
What is the signs and symptoms of these particular bushings needing to be replaced.

Thanks in advance

[hC1001]

Originally Posted by MT0Y

Noob question.. process of elimination for my issue.
What is the signs and symptoms of these particular bushings needing to be replaced.

Thanks in advance

I actually didnt have any symptoms. I visually checked the rear bushing and it was torn. I actually thought it was torn in two places but it was one big tear after removing the bolt. All the front bushings were still good but they are very soft and probably wouldnt tear. i replaced those with PF bushings as well.

[MT0Y]

Thank you again.. will get under it later and have a squizz

[Rokoz]

Originally Posted by RSXDC5

It depends on if you have the v1 or v2 oem rear diff bushing. V1 is fluid filled and prone to cracking by 20k miles even, v2 is poly

How do I find out which one I have?

[hC1001]

Originally Posted by Rokoz

How do I find out which one I have?

The pic two post up is v1. v2 is very different.

[hellokitty]

Any update to the clunking issue with using Powerflex purple bushings? I’d rather use a stiffer bushing and deal with the constant diff noise than to use a softer bushing and have a clunking sound every time I accelerate haha

[rborane]

Originally Posted by hellokitty

Any update to the clunking issue with using Powerflex purple bushings? I'd rather use a stiffer bushing and deal with the constant diff noise than to use a softer bushing and have a clunking sound every time I accelerate haha

I still get the clunk, but mine is DCT so that may have something to do with it with the diff. I have a buddy with the same bushings and bracket but 6MT with no clunk . That's why I am curious how the ECS are, to see if the clunk goes away

[hC1001]

Originally Posted by hellokitty

Any update to the clunking issue with using Powerflex purple bushings? I’d rather use a stiffer bushing and deal with the constant diff noise than to use a softer bushing and have a clunking sound every time I accelerate haha

I dont get any clunks but i am 6 spd manual...