[totalguy]

my E90 2006 has the rear end all polybushed and ive got some diff whine at 30mph give or take its not bad but id like to get rid of it. surely others have come across this issue when poly bushing the rear how can it be solved? preferably without changing bushes hopefully.

[edycol]

Originally Posted by totalguy

my E90 2006 has the rear end all polybushed and ive got some diff whine at 30mph give or take its not bad but id like to get rid of it. surely others have come across this issue when poly bushing the rear how can it be solved? preferably without changing bushes hopefully.

Reason i didn't go poly on diff.
When I was researching this prior to doing work, I couldn't find settled way how to resolve it.

[335i54n]

if your diff is whining with poly or solid bushing then its at minimin pretty tired. with a stiffer rear end, at least you can now hear any changes in pitch and volume and keep an ear on it. if you got a constant whine that increases with speed, you need to look at your diff more closely. if you got a light whine on/off gas then you should be ok for a while, just keep an ear on things

[Torgus]

Originally Posted by totalguy

my E90 2006 has the rear end all polybushed and ive got some diff whine at 30mph give or take its not bad but id like to get rid of it. surely others have come across this issue when poly bushing the rear how can it be solved? preferably without changing bushes hopefully.

Yeah go back to stock or m3 bushings. Solid bushings = diff whine. Some mods add NVH. This is one of them. Personally I like it

Why you have whine only at 30 mph is odd.

[totalguy]

Originally Posted by edycol

Reason i didn't go poly on diff.
When I was researching this prior to doing work, I couldn't find settled way how to resolve it.

didnt have the work done myself. its not bad its more annoying than anything

[totalguy]

Originally Posted by Torgus

Yeah go back to stock or m3 bushings. Solid bushings = diff whine. Some mods add NVH. This is one of them. Personally I like it

Why you have whine only at 30 mph is odd.

well i dont have VH i have some N though

Its quite simple, at that speed the harmonic balance is reached its peak. I'm wondering about adding more weights to it though, changing the bush is a pain you need a special tool.

[totalguy]

Originally Posted by 335i54n

if your diff is whining with poly or solid bushing then its at minimin pretty tired. with a stiffer rear end, at least you can now hear any changes in pitch and volume and keep an ear on it. if you got a constant whine that increases with speed, you need to look at your diff more closely. if you got a light whine on/off gas then you should be ok for a while, just keep an ear on things

ive no fears about the diff it was my brother who owned the car before me and he wouldn't lie about things, he told me its faults and all the new stuff its had etc. He told me its just the bush and its not noisy all the time only about 30mph otherwise its all quiet

[Torgus]

Originally Posted by totalguy

ive no fears about the diff it was my brother who owned the car before me and he wouldn't lie about things, he told me its faults and all the new stuff its had etc. He told me its just the bush and its not noisy all the time only about 30mph otherwise its all quiet

Don't drive 30 mph?

What you are describing is much better than what the metal solid bushings produce for sound.

[totalguy]

Originally Posted by Torgus

Don't drive 30 mph?

What you are describing is much better than what the metal solid bushings produce for sound.

if only it were that simple lol as you say though could be worse