Whiteline Rear Transmission Insert Noise in Decel Only

[M0nk3y]

Pretty much what the title states.

Installed whiteline transmission mount insert bushing in addition to STi Engine Mounts this off-season. Went to go drive around the block and I was greeted with this noise on deceleration:

[ame]https://www.youtube.com/watch?v=bCDWsh5iKAI[/ame]

The video is some nasty noise happening on decel only. Kicking in the clutch or coasting/accel the noise is no longer apparent.

Swapped back to OE bushings and noise no longer there, thinking I torqued something wrong I reinstalled the insert bushing and once again bad noises crept up instantly.

Currently back on OE bushing, just trying to figure out why I’m having such a dramatic impact. Only other thing changed out are STi Engine mounts. Everything else is OEM within the drivetrain.

One last thing, car has 15,000 miles on it. I bought it new/I’m original owner

[StraightOuttaCanadaEh]

I have the Perrin engine mounts, the Whiteline shifter bushing and perrin trans insert and I have very similar noises. I wouldn't worry, although it'd be good to check

[churchx]

With less compliant bushings usual thing is that vibrations/noises don't just dissapear if you remove one of dampening elements, it usually just gets transfered elsewhere and sometimes amplified, if in contact with some other parts.
So unless it's track specialized build, i'd probably choose which parts in drivetrain seem more worthy candidates for stiffer bushings, and leave rest alone.
At one point i had TRD engine mounts, perrin shifter bushing and trans insert, whiteline diff inserts (probably to completely make it unbearable only one-piece driveshaft missing ). Reverted only to perrin gearbox related ones. Not completely w/o NVH impact (slight SC like gear whine in 1st & 2nd of telerable levels), but they still provide better shifting feel (together with redline MTL oil), but at least i get less noise of clutch related/grip change related tranny shocks induced and engine vibrations produced noises. If one removes all damping, all possible noises are passed to car body acting as resonator :/, nowhere "to go"/to be passed for vibrations/noise. The more bushings you replace, even if by reviews from others many of them may have very little individual impact on NVH, the much worse multiplied "sum" of NVH impact results, so i can only advise to choose what you want to change most, not all.

[Alpha86]

I have this same issue after installing the Whiteline insert. Its completely normal, stiffer bushings will pretty much always increase NVH in some way.

[86TOYO2k17]

i have sti mounts, whiteline trans insert, whiteline support outrigger insert, carbon fiber driveshaft, and i have zero added NVH under any scenario.

however when i installed whiteline positive traction kit as soon as i hit 70mph my rear end felt like a washing machine, vibrated so bad i could barely see straight. Drove straight home and took them off, back to zero NVH. i know many people have used the traction kit with no issues so i think it was the straw that broke the back so to speak.

Also i have an AUTO not an MT so maybe that makes a difference why i have no NVH.

[Grady]

Originally Posted by Alpha86

I have this same issue after installing the Whiteline insert. Its completely normal, stiffer bushings will pretty much always increase NVH in some way.

Same thing here. No issue for me I knew going in NVH would increase.

[Grady]

Originally Posted by 86TOYO2k17

i have sti mounts, whiteline trans insert, whiteline support outrigger insert, carbon fiber driveshaft, and i have zero added NVH under any scenario.

however when i installed whiteline positive traction kit as soon as i hit 70mph my rear end felt like a washing machine, vibrated so bad i could barely see straight. Drove straight home and took them off, back to zero NVH. i know many people have used the traction kit with no issues so i think it was the straw that broke the back so to speak.

Also i have an AUTO not an MT so maybe that makes a difference why i have no NVH.

The bushings will not cause a vibration they will just show you you have a vibration that the other bushings are hiding. I would but the bushings back in and find the issue. Probably the CF driveshaft.

[M0nk3y]

Originally Posted by Grady

Same thing here. No issue for me I knew going in NVH would increase.

I guess my question/issue is that NVH is only apparent on decel. Nothing has changed or at least noticeable on acceleration and coast.

Reverse as well is a nightmare, it sounds like the transmission is seizing. I realize it appears like it’s overreacting, but it’s a terrible noise.

Coming from someone who did 80A durometer bushings on my previous 128i, along with black power flex race differential bushings, I’ve never experience a noise specifically related to one specific portion of driving. If that makes any sense at all


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[86TOYO2k17]

Originally Posted by Grady

The bushings will not cause a vibration they will just show you you have a vibration that the other bushings are hiding. I would but the bushings back in and find the issue. Probably the CF driveshaft.

None of them will cause a vibration alone because none of them are causing an issue/vibration now nor thousands of miles before or after install/removal of the rear subframe inserts. And the least beneficial of those mods is the rear subframe inserts. So putting them back in would be pointless. The issue is the combined stiffness across the entire drivetrain including the rear subframe insert. Removing any of the mounts/inserts/cf ds could and possibly would eliminate it but why remove something more beneficial when the issue is resolved from eliminating the least beneficial. My car before install and after removal is butter smooth no NVH beyond what it was from factory at any speed 0-130+mph cruising, accelerating , or decelerating, up hill or down hill doesn’t matter.

[cueball89]

Had a similar experience with my old wrx. Sti engine and transmission mounts with some poly bushings thrown in yielded deacceleration noises similar to what you are experiencing. Never had noise under any other circumstances. I happened to be in MD and had Andrewtech Automotive take the car for a test drive, they said it was normal. I put 100,000 more miles on the car without any issues.