BMR Poly Differential Bushing Gear Whine Solution

[Obsessed]

Anybody come up with a solution for the diff whine after installing the new bushings? Its starting to bother me. Even contimplating trying to get the stock bushing reinstalled.

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[BMR Tech]

There are a few things that I have seen done, and recommended to customers that have a true bushing in the diff.

One is, filling the IRS Cradle with spray foam (I actually saw this recommended by FTBR with their bushing solutions) and the other one is Dynamat material applied to the underside of the rear seats on the floorpan as well as the underneath the trunk pads.

The good news is that the OEM Bushings are available for the diff mounts. Not sure if they are still not able to be had, but the OEM Cradle bushings are NOT available to my knowledge.

 

[Obsessed]

There are a few things that I have seen done, and recommended to customers that have a true bushing in the diff.

One is, filling the IRS Cradle with spray foam (I actually saw this recommended by FTBR with their bushing solutions) and the other one is Dynamat material applied to the underside of the rear seats on the floorpan as well as the underneath the trunk pads.

The good news is that the OEM Bushings are available for the diff mounts. Not sure if they are still not able to be had, but the OEM Cradle bushings are NOT available to my knowledge.

Thanks for the quick response. Do you know if anyone had success with the dynomat or spray foam?

 

[BMR Tech]

I have had several people tell me that those worked pretty well.

I have not done them myself, because swapping to the 9" Strange Center section made all my horrible noises go away. lol - Imagine that.

 

[Obsessed]

I have had several people tell me that those worked pretty well.

I have not done them myself, because swapping to the 9" Strange Center section made all my horrible noises go away. lol - Imagine that.

What does a strange center section replace? Guessing its more than just the pumpkin.

 

[kcc0521]

Is it possible that the CB005 kit can transfer some of the DIFF noise the the cabin? I never noticed wine in my car until the day I installed my cradle lockouts. I did go to the track the same day so it is possible I damaged something.

 

[Coaster]

Is it possible that the CB005 kit can transfer some of the DIFF noise the the cabin? I never noticed wine in my car until the day I installed my cradle lockouts. I did go to the track the same day so it is possible I damaged something.

Did you already have diff bushings or inserts in place when you did the CB005?

It seems like you can do either diff or cradle bushings/inserts with no noise. Once you do both is when the noise starts to transfer inside the car.

 

[Obsessed]

Both David from Steeda, Kelly from BMR siad diff bushings and inserts will increase nvh. In particular diff gear noise/whine.

 

[Obsessed]

I have a question for those who have installed the Poly Diff bushings.

I just did the install myself with Delrin cradle bushings. There is an audible knock. Nothing feels loose but it sounds like I can hear the ring and pinion bounce back and forth off each other due to the backlash. Is anyone else hearing this?

I never got a knock. I would recheck everything and make sure all bots are properly torqued especially on the differential an driveshaft bolts.

I will say that I got a lot of gear whine while cruising at highway speeds. Got so annoying I purchased a used subframe on ebay and switched it out. Also, interesting info, I think BMR discontinued the poly and delrin bushings. All you can get now are the aluminum bushings.

Good luck.

 

[Jeff_oddo]

There are a few things that I have seen done, and recommended to customers that have a true bushing in the diff.

One is, filling the IRS Cradle with spray foam (I actually saw this recommended by FTBR with their bushing solutions) and the other one is Dynamat material applied to the underside of the rear seats on the floorpan as well as the underneath the trunk pads.

The good news is that the OEM Bushings are available for the diff mounts. Not sure if they are still not able to be had, but the OEM Cradle bushings are NOT available to my knowledge.

I’m going to have to try this... as a DD, the gear whine is just annoying. I’m gonna try the foam spray along with the dynomat. Should help some...

 

[xXANCHORMONXx]

Give it some time.

It will get better

 

[wildcatgoal]

Is it possible that the CB005 kit can transfer some of the DIFF noise the the cabin? I never noticed wine in my car until the day I installed my cradle lockouts. I did go to the track the same day so it is possible I damaged something.

Yes, in every case I've been in and installed a CB005, there was increased transmission of Torsen differential noise into the cabin. The other diff didn't seem to make as much noise in the first place, so less noise to the cabin.

Differential bushings (or bushing inserts to a lesser degree), even the softest ones, will increase NVH. In terms of inserts, the difference between the red and black ones is almost negligible. The difference between red/black and the aluminum ones... again, not that much. Which is why I have the aluminum ones in my car (I started with the red ones). My differential is also through-bolted, which increases NVH some. Overall though, it's not bad at all with what I have on my IRS/diff. I've been in a car with aluminum (Ford Performance) IRS and differential bushings -- that made some noise, haha.

 

[TheLion]

I had a decent amount of gear whine in my 2016 Ecoboost after installing a 3.73 Torsen from a 2015 wrecked GT i bought to $600 (really good deal as they normally sell for $2k new and about $1k used).

I used the steeda black poly bushings in my Ecoboost. But my 2016 GT has NO gear whine with it's stock 3.73 Torsen diff and the steeda Red bushings.

Red setup does seem a little quieter in terms of drive shaft clatter (noticeably more muted than the Ecoboost was with black bushings) when you push in the clutch under load (aka you start to let the clutch out but then have to push it back in to stop in stop and go traffic).

Seems like the pre-load and shimming on the pinion has a dramatic effect on gear whine. Some do it, some don't. But I do know that using 140 vs. stock 85/90 weight gear oil will help in some cases. Might want to give that a try?

Currently my GT has CB005, SP080 lowering springs and Steeda Red Poly diff bushing inserts. FP toe link bearings are going in this weekend, but it is surprising quiet compared to my Ecoboost which had a similar setup. So far this has worked out to be a really balanced street / auto x setup that's not uncomfortable to ride in daily, but gives some reasonable handling when pushed (well I still need a half decent set of tires, but suspension wise it's coming along great).

 

[BmacIL]

My car without any diff bushing inserts (yet, awaiting install) has whine, but that's because it needs fluid changed. After many autocrosses, one night of drag test and tune, and 59k miles, it needs new fluid. I only hear it at higher speed (above 65 mph) and very light load.

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