Transmission Mount: Rouge Engineering vs. Powerflex Yellow

[BodegaBay]

Has anyone used a 70 Durometer polyurethane transmission mount such as the Powerflex Yellow Street units? I've had their Yellow Street tranny mount in a previous Fiesta ST car and loved the slight NVH increase. Alternatively, I've read the positive reviews for the Rouge Engineering mount but wouldn't mind a slight more NVH with the Powerflex.




vs.

[Papa Popov]

I run Rouge's mounts on my daily and am very happy with them. They add a nice bit of feedback when shifting with little to no additional NVH.

[BodegaBay]

Thanks Papa Popov Hope long have you been running the RE unit?

I might just run the Powerflex one first to see if the NVH is acceptable and switch out to RE if it’s not to my liking. I’ve ran Powerflex Yellow Street 70a in another car and liked the results. Was curious if anytime tried a poly mount with the same hardness.

[Papa Popov]

Originally Posted by BodegaBay

Thanks Papa Popov Hope long have you been running the RE unit?

I might just run the Powerflex one first to see if the NVH is acceptable and switch out to RE if it’s not to my liking. I’ve ran Powerflex Yellow Street 70a in another car and liked the results. Was curious if anytime tried a poly mount with the same hardness.

Been running the Rouge mounts for 3 years now with no complaints.

It’s been a hot minute since I dug into this but FWIW I recall reading that unless you’re upgrading your engine mounts as well you won’t get the full benefit of more extreme trans mounts. A chain is only as strong as it’s weakest link yada yada yada.

[BodegaBay]

Thx. That’s a good sign that it still performs well after 3 years. I might just go ahead and order it instead. Does it improve the shifting feel and the connection to the transmission? I just put in a UUC short shifter and it was a huge improvement.

[ZHPizza]

I will always recommend rubber over poly for mounts that see impact/vibration due to the significant difference in damping qualities of the materials. Poly is going to transmit more NVH at the same durometer, so only worth it if you're building a track car and going with much harder mounts along the entire drivetrain.

[spidertri]

I second the Rogue mounts, been running them since 2019, absolutely no issues, minimal NVH difference.

[Papa Popov]

Originally Posted by BodegaBay

Thx. That’s a good sign that it still performs well after 3 years. I might just go ahead and order it instead. Does it improve the shifting feel and the connection to the transmission? I just put in a UUC short shifter and it was a huge improvement.

With the stock mounts I could feel a bit of flex when going into a gear which made the shift feel kinda rubbery. With the rogue mounts shifts feel more "solid" and precise. You know exactly which gear you're in and when it is engaged.

[4JawChuck]

Just an FYI because I’ve never seen it mentioned anywhere before.

When I rebuilt my N52 I had the entire engine and transmission (6spd manual) hanging on the hoist and needed to put it down as I wouldn’t be able to install until the next weekend. So I put down three jackstands to rest the assembly on the engine mount ears and trans mount, the engine was complete including accessories.

Upon placing the engine on the front mount ears it was obvious the engine was nose heavy and thus the transmission would not sit with any weight on the jackstand placed under it. I had to place 20pds of sandbags on the transmission to hold it down so it wouldn’t tip forward.

Most engine/transmission assemblies are tail
heavy but not these BMW engines, therefore the rear trans mounts are constantly under tension not compression and the engine weight is mostly sitting on the front mounts.

Those transmission mounts are very soft so I get the idea of changing to a stiffer mount but honestly they are mostly there to keep it aligned side to side and absorb vibration…they don’t support anything.

Thought I should mention it as it was one of the items I was going to replace along with the shifter mounts which are 99% of the shifter feel problem.

[spidertri]

I don't really agree with that, when you change the transmission mounts with the engine in the car you have to jack up the transmission to be able to swap the mounts.

Once it's unbolted the tail of the transmission doesn't move upwards and you definitely do not need to pull down on the transmission to tighten the mount hardware.

[4JawChuck]

That’s because the driveshaft is attached.

Added a proof photo, you can see the sandbags hanging off the tail shaft, now that I look at it might be more than 20pds.

[spidertri]

Fair enough, there is a lot of the motor hanging well past the engine mount points.

But to your point, in the car the driveshaft is attached, the weight of the driveshaft doesn't allow the tail of the transmission to move upwards and the mounts aren't constantly in tension.

[4JawChuck]

The front engine mounts pivot in their ball socket and are preloaded to hold the back of the engine down once installed.

Basically the engine mount pretension balances the nose heavy engine so the engine is balanced on the engine mount.

I don’t make this stuff up, if you take one apart you will see. In other words there is no load on the trans mounts.

[kilo3407]

Did you guys change engine mounts as well when changing to these trans mounts?

Considering leaving my 128k km, somewhat worn but not broken, engine mounts in, and just upgrading trans mounts.