E28 M5 motor mount part #?

[Brew]

Replacing my green 535 mounts this week before I hit the track Thursday.

The ETM lists a left and a right M5 mount (black "hockey puck" style). Which is the right one to use or do I get one of each?

[static]

please report back on added NVH. I am considering replacing my e28m5 puck ones for softer green ones

[BigD]

The right one is the one you want. The other side is the same V mount as the 535. The M5 cylinder mount should also be taller, and not require spacers... fingers crossed, gonna use them on both sides.

[Brew]

Awesome. I'll update this thread on any additional NVH and whether or not I needed any spacers.

[static]

6-7mm spacer is what used on mine (driver side) to clear the IX booster (fins are shaved too) and still the clearence is around 2-3mm (scarry)
Both of my mounts are cylinder ones.

[dougsic]

Is there a disadvantage to using the green mounts?

When my swap was first completed, I also had the cylindrical mounts installed.

The transmission support was stock thus crushing the right side tranny mount and stretching the left side one but I didn't think it would be an issue.

Well, it was. Within two months, the left side transmission mount sheared off and the left cylindrical motor mount tore allowing the engine to shift forward under moderate braking. The fan contacted the radiator, damaging both.

I replaced both cylindrical mounts with the green metal ones.

To get the exhaust to clear, I only had to use the washer seen below.

I originally shaved the intake plenum fins and there is still plenty of clearance.

I will admit that the cylindrical mount failed due to my negligence but I feel safer using the green ones as I can't see how they would ever fail.

[static]

^^ so did you notice difference in vibration / ride quality after you changed for green mounts?

[dougsic]

^^ so did you notice difference in vibration / ride quality after you changed for green mounts?

Good question.

My car is uber stealth hence my insistance of a quiet exhaust (as you know from earlier posts). So, I am extremely sensative to anything that doesn't appear to be exactly stock.

Changing the motor mounts from cylindrical ones to the green ones, I could feel no more vibrations in the steering wheel, shifter or anywhere in the passenger compartment. And that includes going from stock transmission mounts to the much stronger e21 ones. But of course that also included fixing the transmission support issue too.

It is possible that I was getting some vibration from the smashed tranny mount and now I'm getting about the same amount from the green motor mounts, but I seriously doubt it.

There is a local e30 meet scheduled for next month. Maybe I'll let a few m20 owners drive my car and see if they notice any unusual vibrations. I doubt they would from the passenger seat but let's see about that.

Note that I do not have the e21 tranny mount cups.

Maybe I'm lucky that my s50 idles smoothly even when running the A/C which I do often. The temperature gauge remains steady a little below the halfway mark and I'm getting about 24 MPG of very spirited driving.

[1990m3]

i don't understand the vibration problems you guys are having. i've done 3 motor installs now and both have the green e28 mounts and e21 trans mounts with cups on them and there are zero vibrations. I've been daily driving mine for a year and it's fine.

Dougsic - check to see that your trans mounts are all tightened securely and not stretched out to reach the mounting point on the trans. Are you using a getrag or ZF trans?

[Brew]

Both of my green mounts have torn at the lower stud and compressed enough that I've had to add an additional 1/4" of spacing for the oil pan to clear the rack. This is after about 30k daily-driven miles, about 7 autocrosses.

Never had any vibration issues with either of my swaps, though.

[dougsic]

i don't understand the vibration problems you guys are having. i've done 3 motor installs now and both have the green e28 mounts and e21 trans mounts with cups on them and there are zero vibrations. I've been daily driving mine for a year and it's fine.

Dougsic - check to see that your trans mounts are all tightened securely and not stretched out to reach the mounting point on the trans. Are you using a getrag or ZF trans?

I agree 100% about the vibrations.

Thanks for the suggestion about the trans mounts but I fixed the problem forever by modifying the transmission support bracket. I just didn't know better in the beginning.

[dougsic]

Both of my green mounts have torn at the lower stud and compressed enough that I've had to add an additional 1/4" of spacing for the oil pan to clear the rack. This is after about 30k daily-driven miles, about 7 autocrosses.

Never had any vibration issues with either of my swaps, though.

Thanks for pointing out the compression. I was concerned about that before - now I know to keep an eye on the clearance.

I have over 20k street miles but no track time with no problems to date.

[AlexFunction2ND]

i don't understand the vibration problems you guys are having. i've done 3 motor installs now and both have the green e28 mounts and e21 trans mounts with cups on them and there are zero vibrations. I've been daily driving mine for a year and it's fine.

Did you have to widen the mounting holes on the transmission brace to get your e21 mounts to fit? The mounts I purchased (supposedly e21 mounts) wont fit my tranny bracket unless drill out the mounting holes...

[FredK]

Yes, using the E21 mounts will require drilling the transmission bracket holes. They are a tad too small.

[1990m3]

Did you have to widen the mounting holes on the transmission brace to get your e21 mounts to fit? The mounts I purchased (supposedly e21 mounts) wont fit my tranny bracket unless drill out the mounting holes...

yes but I didn't really consider that a big deal. 2 minutes with the die grinder and i was back in business.