135i vs. 1M/M3 Front Upper Strut Mount

[rhodesman]

In my ever-increasing attempt to "fix with mods" my drivers side upper strut mount is bad. So I started to look into replacment parts and out of curiosity, I searched for the strut mount for a 1M as well as my 135i. Interestingly enough, the 1M strut mount is very different than the 135i strut mount, and looks a lot more "rigid" of a part.

Naturally, I'm thinking this is a worthy upgrade. My question is, would this be compatible with my 135i front struts if I replace nothing else? Or, would I need to replace all the strut parts and thus end up having to swap my whole front strut assembly to get these to work? If it's the latter, then "meh" I'm not going to dive into that craziness yet, but if it's a true bolt on swap, it might be worth a shot.

Anyone want to weigh in on this?

For comparison:
135i Front Upper Strut Mount (part#: 31336760943):


135i Strut Mount Link

1M Front Upper Strut Mount (part#: 31302283650):



1M Strut Mount Link

[asbrr]

Originally Posted by rhodesman

In my ever-increasing attempt to "fix with mods" my drivers side upper strut mount is bad. So I started to look into replacment parts and out of curiosity, I searched for the strut mount for a 1M as well as my 135i. Interestingly enough, the 1M strut mount is very different than the 135i strut mount, and looks a lot more "rigid" of a part.

Naturally, I'm thinking this is a worthy upgrade. My question is, would this be compatible with my 135i front struts if I replace nothing else? Or, would I need to replace all the strut parts and thus end up having to swap my whole front strut assembly to get these to work? If it's the latter, then "meh" I'm not going to dive into that craziness yet, but if it's a true bolt on swap, it might be worth a shot.

Anyone want to weigh in on this?

Unlikely the 1M part will fit, it has quite a bit of a different suspension (M3 based). Haven't heard of anyone installing this part instead of the stock part.

One thing you could do is use part number 31306775098, which is a heavier duty part used on the e90 sedans (extra weight/loads etc). It is apparently made from steel vs the aluminum of 31336760943 and it costs a bit more.

A lot of people use these as an "upgrade". It is dimensionally identical, just tougher.

HTH

[rhodesman]

Originally Posted by asbrr

Unlikely the 1M part will fit, it has quite a bit of a different suspension (M3 based). Haven't heard of anyone installing this part instead of the stock part.

One thing you could do is use part number 31306775098, which is a heavier duty part used on the e90 sedans (extra weight/loads etc). It is apparently made from steel vs the aluminum of 31336760943 and it costs a bit more.

A lot of people use these as an "upgrade". It is dimensionally identical, just tougher.

HTH

ooh! I think this is the right path to go down for me right now, thank you!

[Washington335i]

Agree 100% on the -5098 e90 strut mount. Do not use the 1M mount - I do not think it will clear the front upper spring perch.
Best regards, Chris

[John_01]

When you use these, you should also get 1M shocks, springs, front knuckles, hubs, wheel bearings, 1M Brake discs, brake calipers, 1M front fenders, inner guards, and 1M front bumper to go with them. It should be a sweet setup!

[Clovef]

Originally Posted by John_01

When you use these, you should also get 1M shocks, springs, front knuckles, hubs, wheel bearings, 1M Brake discs, brake calipers, 1M front fenders, inner guards, and 1M front bumper to go with them. It should be a sweet setup!

Don't forget the 1M steering rack if you are doing the rest of the front end.

Thanks for pointing out the e90 part. I may end up doing these as well.

[dtla1]

http://www.1addicts.com/forums/showthread.php?t=1296087

[rhodesman]

Originally Posted by John_01

When you use these, you should also get 1M shocks, springs, front knuckles, hubs, wheel bearings, 1M Brake discs, brake calipers, 1M front fenders, inner guards, and 1M front bumper to go with them. It should be a sweet setup!

uuuhhh, yeah this! It is my intention to end up with a 1M convertible clone (is it still considered a clone if there was no 1M vert!?). For now however, I'm going to work on the rear first. I did swap out the front lower control arms which was a huge improvement overall and shed a good bit of understeer which is...fun. However, now I can feel the back wiggling about with all that non-M bushing slop when I put the hammer down. Time to get that all buttoned up!

[HP Autosport]

Originally Posted by asbrr

Unlikely the 1M part will fit, it has quite a bit of a different suspension (M3 based). Haven't heard of anyone installing this part instead of the stock part.

One thing you could do is use part number 31306775098, which is a heavier duty part used on the e90 sedans (extra weight/loads etc). It is apparently made from steel vs the aluminum of 31336760943 and it costs a bit more.

A lot of people use these as an "upgrade". It is dimensionally identical, just tougher.

HTH

The E9x version doesn't seem to last any longer than the E8x version though. The rubber still compresses over time and eventually cracks. The bearing still becomes noise after 50K miles and sometimes sooner.

If you are going to have your front struts, it's a good idea to replace these at that time to save you labor time down the road.