Any experience with RevShift solid rear subframe mount bushings?

[IamFODI]

Want to do solid subframe mount bushings in the next year or so and leaning toward RevShift because FCP Euro sells them. It's not that I expect to have to return them for wear or anything; I just like to stick with FCP Euro on principle where possible.

Reviews on RevShift's other stuff seem to be... mixed. But I haven't seen any on their solid subframe mount bushings, and those seem like a really straightforward part.

Anyone use this part and/or have any thoughts?

[DRLane]

Go with solid aluminum, if you're pulling the subframe might as well do it once.

[IamFODI]

Originally Posted by DRLane

Go with solid aluminum, if you're pulling the subframe might as well do it once.

Yep, they are aluminum.

https://www.fcpeuro.com/products/bmw...vshift-asb-e9x

[DRLane]

Originally Posted by IamFODI

Yep, they are aluminum.

https://www.fcpeuro.com/products/bmw...vshift-asb-e9x

Sounds like you're squared away! Haven't seen the two piece aluminum before. Good luck and enjoy

[IamFODI]

Originally Posted by DRLane

Sounds like you're squared away! Haven't seen the two piece aluminum before. Good luck and enjoy

Would you run these in the absence of reviews, and given RevShift's other products have a spotty rep?

[DRLane]

Originally Posted by IamFODI

Would you run these in the absence of reviews, and given RevShift's other products have a spotty rep?

I'd go with tried and true options from any of the other players. But 🤷🏻*♂️

[ganz]

I have these subframe bushings (2-piece aluminum) in my car. No noticeable difference between these and other E9X that I have driven with Turner or MRF bushings. I went with these because of the claims around "sandwiching" the subframe which I have no clue whether makes any difference at all. The important thing is it doesn't make noise.

[e92zero]

That look interesting and probably make installation easier. But from the pic, it doesn't look like the part inserted into the subframe are round? Maybe it's designed for easy of installation. Not sure if it has any long term effect?

[Redd]

Were these Revshift two-piece units easier to install than the other one-piece ones?

[IamFODI]

Coming back to this as I'm planning to order soon.

I just emailed Revshift about e92zero's question and a couple more. We'll see what they say.

For now, I'm kind of leaning toward another option like Bimmerworld. Hard to imagine Revshift knows more about how to build a product for this platform than Bimmerworld does. Let's see if Revshift comes back with anything potentially mind-changing.

[IamFODI]

Wow. Got an amazingly fast answer – on a weekend, no less. Nice counterpoint to all the allegations of horrible customer service.

No, they're not round; yes, that's for easy installation, esp. in out-of-round bores. Apparently they provide 6 points of contact with the bore.

On the "sandwich" aspect: they allege that one-piece designs can allow the subframe to move up to an inch vertically. Has anyone heard of that happening? If it were, wouldn't there be a lot of failures in short order as the steel subframe bores basically shredded the aluminum bushings? The fact that that's not happening makes me feel like it's not an issue.

Maybe the "sandwich" aspect of the Revshift bushings was necessary because of the not-entirely-round 2-piece design – i.e., less-tight fit with fewer points of contact = more potential for movement.

They also said the flange cutouts on all other designs are not functional, which is why their flanges go all the way around. Not sure how to reconcile that with TMS's instructions for their aluminum subframe bushings, which say you have to make sure the flanges are oriented correctly....

Revshift seems to be the only company making solid aluminum subframe bushings like this. AKG's offering is the only one I've seen that seems to be 2-piece, and they look round; all the others I've seen – Bimmerworld, TMS, Precision Works, CMP, etc. – are 1-piece and round. Makes me wonder if there's a reason...

[Scharbag]

Originally Posted by IamFODI

Wow. Got an amazingly fast answer – on a weekend, no less. Nice counterpoint to all the allegations of horrible customer service.

No, they're not round; yes, that's for easy installation, esp. in out-of-round bores. Apparently they provide 6 points of contact with the bore.

On the "sandwich" aspect: they allege that one-piece designs can allow the subframe to move up to an inch vertically. Has anyone heard of that happening? If it were, wouldn't there be a lot of failures in short order as the steel subframe bores basically shredded the aluminum bushings? The fact that that's not happening makes me feel like it's not an issue.

Maybe the "sandwich" aspect of the Revshift bushings was necessary because of the not-entirely-round 2-piece design – i.e., less-tight fit with fewer points of contact = more potential for movement.

They also said the flange cutouts on all other designs are not functional, which is why their flanges go all the way around. Not sure how to reconcile that with TMS's instructions for their aluminum subframe bushings, which say you have to make sure the flanges are oriented correctly....

Revshift seems to be the only company making solid aluminum subframe bushings like this. AKG's offering is the only one I've seen that seems to be 2-piece, and they look round; all the others I've seen – Bimmerworld, TMS, Precision Works, CMP, etc. – are 1-piece and round. Makes me wonder if there's a reason...

What did you go with? I am also looking to pull the trigger on this and would like to know if the RevShift's from FCP are any good.

Cheers,

[chocstraw]

I have these and they work just fine. Quality aluminum, they pressed in just fine.

[kaiv]

Originally Posted by IamFODI

On the "sandwich" aspect: they allege that one-piece designs can allow the subframe to move up to an inch vertically. Has anyone heard of that happening? If it were, wouldn't there be a lot of failures in short order as the steel subframe bores basically shredded the aluminum bushings? The fact that that's not happening makes me feel like it's not an issue.

FWIW every solid mount I've installed (Bimmerworld, Turner, AKG, CMP) have a nice interference fit where the subframe moving over the mounts is definitely not an issue.

[fengrr]

I have bimmerworld installed currently with no issue.

[M3SQRD]

That’s one way to market your two-piece hexagonal subframe bushing…scare everyone by telling them your subframe is going to move by up to 1” while driving, if you don’t use ours I’ll stick with BimmerWorld. Unless I missed them, I don’t recall ever reading a thread discussing not being able to press fit a cylindrical subframe bushing into circular holes in the subframe or threads talking about subframes falling of a car while cornering. Good job RevShift

[IamFODI]

Originally Posted by Scharbag

What did you go with? I am also looking to pull the trigger on this and would like to know if the RevShift's from FCP are any good.

Cheers,

Apologies for being out of the loop.

I ended up going with the Bimmerworld ones. Massive PITA to press in, which made Revshift's approach seem pretty reasonable, at least in theory. If I imagine they went with the hexagonal design for ease of install (apparently all you need is a hammer), and then figured they could rely on the flanges rather than the interference fit to keep the subframe locked in, it makes sense.

No regrets going with BW, though.

[MaximusB]

Chiming in about two piece SF bushing design. FWIW. I initially purchased the AKG solid subframe mounts and they are two piece design meant to sandwich the subframe. However when I went to install them I found out the tolerance was way off. I could drop them into the subframe by hand/gravity and they move around once inside the subframe.

Here is my video showing how easy they went into the subframe.
https://youtube.com/shorts/SO_iG7SU0Pg?feature=share

I emailed AKG and they said that is normal and they made them that way for ease of installation. They claim that everything will tighten up once it is installed and torqued to spec. I can see this logic work if it was poly bushings, but there's no way anyone can convince me that the subframe bolts alone would compress solid metal enough to keep everything tight. I wasn't gonna risk going through all the work of putting the car back together just to find out these bushings rattle around. It would suck if they did move around and I had to uninstall everything to in different bushings.

Long story short - I returned the AKG solid subframe bushings and went with BW one. The BW one wasn't that bad of an install. I pressed all of them with a bushing press tool and impact gun.

[M3SQRD]

Originally Posted by MaximusB

Chiming in about two piece SF bushing design. FWIW. I initially purchased the AKG solid subframe mounts and they are two piece design meant to sandwich the subframe. However when I went to install them I found out the tolerance was way off. I could drop them into the subframe by hand/gravity and they move around once inside the subframe.

Here is my video showing how easy they went into the subframe.
https://youtube.com/shorts/SO_iG7SU0Pg?feature=share

I emailed AKG and they said that is normal and they made them that way for ease of installation. They claim that everything will tighten up once it is installed and torqued to spec. I can see this logic work if it was poly bushings, but there's no way anyone can convince me that the subframe bolts alone would compress solid metal enough to keep everything tight. I wasn't gonna risk going through all the work of putting the car back together just to find out these bushings rattle around. It would suck if they did move around and I had to uninstall everything to in different bushings.

Long story short - I returned the AKG solid subframe bushings and went with BW one. The BW one wasn't that bad of an install. I pressed all of them with a bushing press tool and impact gun.

Thanks for the heads up on AKG subframe using! Correct, you are developing preload and the off-axis deformation is relatively small. Even if the bushing gets lightly contact with the subframe, it’s nowhere near the preload of pressed in bushings. With their approach, it likely could cause the subframe to move by one inch as it’s falling off to the ground as subframe bolts are continually severely stretched bolts. Wise choice returning them and going with the BW subframe bushings.