[pbonsalb]

Bought comp mounts for my base. Any install tips? Have done mounts on E36 M3, E39 528i, E61 535xi, E90 M3 but not an F90.

[Maverik259]

what are the part numbers? if not insane i am interested in this as well down the line. I'm sure there is a bmw service doc someone has access to.

[pbonsalb]

22-11-8-089-821
22-11-8-089-822

[Maverik259]

Originally Posted by pbonsalb

22-11-8-089-821
22-11-8-089-822

$120 a pop. Not bad. Such a curious thing to modify for bmw. Curious if anyone has been in both can actually tell the difference.

[SGMM5]

I contemplated swapping to CS mounts but checked out the BMW procedure and it's pretty crazy.

Hopefully you are able to find a simpler way to access and swap them out. If you do I'd be curious to know and perhaps try it myself.

[pbonsalb]

I did not have a manual and no one had any guidance. It was not any fun. The subframe was not cooperative — it must come down but did not seem willing. I did have the two skinny horizontal long bolts removed on each side up front but the subframe seemed locked into that other frame. I had the steering rack unbolted and the steering pump wiring harness loosened. I ended up having to unbolt the motor mount arms to make space and even then it was a really tight squeeze on the drivers side due to the trans cooler pipes/hoses.

I have since bought an online manual for whatever it is worth for future use. It would have been better to have had it before I started….

I had dropped the subframe on my E90 M3 and E61 535xi when doing rod bearings so I am familiar with the general process even on an AWD motor but must have been missing a step here.

Anyway the comp mounts and Dinan monoballs are in. The monoballs were another fiasco. I did them on the car since removing the hub end looked like it might require pulling the axle. My driver/receiver stripped the threaded rod so I drilled out the rubber and then folded up the outer sleeve. I have done this before but it’s not my preferred technique. The bolt hole in the stock bushing was not big enough for my heavy duty bushing pullers. In hindsight, I should have drilled it out and then used the heavy duty piece. It’s aluminum so drilling would have worked. Installing the monoballs is easy since they drop in and are not pressed in.

EDIT: On the monoballs, do them the way this member did by removing the arms and pressing out the stock bushings:

https://f90.bimmerpost.com/forums/sh...1868383&page=5

[Used2be]

Originally Posted by pbonsalb

I did not have a manual and no one had any guidance. It was not any fun.

You are a brave and optimistic man! That would be scary to dive into without some printed instructions, and even then BMW often assumes the mechanic knows much more than is on the page. Just worrying about all the wiring and hoses as the subframe was coming down inch by inch, much less making room for the mounts to be changed! I hope the effort will prove to be worth the hassle.

On my first disassembly for the HAS kit, I didn’t replace the collar screw for the output shaft, thinking a screw that substantial could withstand more than one torquing sequence. When I did the tension strut though, I chickened out and bought a replacement to avoid a third torquing. Torquing it to 155 ft lbs, with 90 degrees of rotation afterwards is unsettling for me. The sickening feeling of that bolt shearing off as you’re torquing it would be unpleasant. With hindsight, I would have done both at the same time.

[pbonsalb]

I have H&R M5 springs on order so I will be doing some of the HAS work you did. Any tips or tricks? I did find a DIY for accessing the rear interior. And bought the APlus Workshop Manual but have not looked at it yet.

[Used2be]

Originally Posted by pbonsalb

Any tips or tricks?

The only surprise for me was getting the shock out of what BMW calls the spring strut holder in the front suspension. Hadn’t dealt with that type of system before and didn’t realize how much I had to lever down, I guess it was the hub, with a long pry bar to get the detached output shaft low enough to allow the strut holder to clear so it could be removed. My memory is hazy, it’s been a couple of years, but I think I jury rigged a loop of rope around the hub in some way so the pry bar could pivot on a jack stand inboard of the suspension, with the short end pressing up onto a solid part of the undercarriage of the car, while I pressed down on the end by the hub that went through the loop. That gave me room to release the strut holder. Without the pry bar I was about an inch away from achieving release.

I remember calling my friendly service manager at the dealership, and he asked his mechanic. They just pry it down he said, and it worked. They might have a more sophisticated system….I hope!

You sound like you have a proper lift to work on, but my version was done with the car only about 21” off the floor on a QuickJack. But you’ll find a way once you know you need enough clearance. I printed out instructions from newtis in 2019, and glad I did. The prying wasn’t mentioned, only “Feed out and remove the spring strut holder downward.” But at least they covered the basics.

[TimmyBHGM5]

Would like to know what's the benefit of comp engine mounts, I have checked that the base car have the same mounts as regular 5er, I am interested in upgrading too.

[pbonsalb]

They are stiffer. Supposedly that translates to less movement, which may improve handling as well as the efficiency of power delivery. Probably very very minor changes in terms of what you can actually feel. Maybe on a track an experienced driver could notice.

[m_fife]

For anyone that is brave enough, procedure for left and right mounts attached!

*PDF not available on mobile app.

[pbonsalb]

Reading those instructions is a pretty strong deterrent!

[Used2be]

Originally Posted by pbonsalb

Reading those instructions is a pretty strong deterrent!

I'll take a wild guess that you didn't exactly follow those instructions! Pretty intimidating!