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      06-07-2018, 02:10 AM   #1
goaty
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MPHAS - Driver Side Perch Sits Higher

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So I had my entire kit re-installed because of a clunking/popping noise which was finally fixed but the technician played with height adjustments when troubleshooting and left the front driver side about 12mm higher than the passenger side.

So,

Question 1: Is it normal that I have the driver side perch adjustment near the bottom with maybe a thread or two left to keep within 2mm of the passenger side which is ~1/2 way up the perch?

Question 2: How do I adjust the rear? I can't get that wrench in there to actually turn anything without hitting either the body of the car (wheel well) or some other component. Is there a trick to lowering/raising rear?

Note: I did follow the MPHAS instructions and kept 150kg total in the front seats when tuning height.

Here's the Front Driver Side:


Here's the Front Passenger Side:

Last edited by goaty; 06-15-2018 at 07:12 PM.. Reason: Better formed question.
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      06-07-2018, 07:20 PM   #2
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Were the perches off by this much the first time they installed this setup?
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      06-07-2018, 09:53 PM   #3
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Quote:
Originally Posted by knightarmor View Post
Were the perches off by this much the first time they installed this setup?
To be quite honest, I never even looked or measured to begin with. It looked square so I never had a complaint. They swear the perch was set to the correct position, I can go in and take off the wheel and take pics if that helps. If I remember correctly, the little stickers with part numbers were both half way peeled off (evenly). I just think that is a hell of a discrepancy...maybe I'm being too nit picky.
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      06-15-2018, 12:07 AM   #4
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I have the same issue with the front left Perch
it sits 10mm higher than right side, I also spoke to tech and he reckons it's press fitted on.
even than, if it was no pressed on well enough with the weight of the spring and car it would of forced the higher perch lower and that has not happened.

So i am also lost for words on this as well.
we will be stripping things again to double check as I also got a clunking noise over small sharp bumps.
Full coil overs FTW, If I had to do it all again I would go with Ohlins or JRZ.

Last edited by whoop_ass; 06-15-2018 at 12:46 AM..
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      06-15-2018, 01:00 AM   #5
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Quote:
Originally Posted by whoop_ass View Post
I have the same issue with the front left Perch
it sits 10mm higher than right side, I also spoke to tech and he reckons it's press fitted on.
even than, if it was no pressed on well enough with the weight of the spring and car it would of forced the higher perch lower and that has not happened.

So i am also lost for words on this as well.
we will be stripping things again to double check as I also got a clunking noise over small sharp bumps.
Full coil overs FTW, If I had to do it all again I would go with Ohlins or JRZ.
Really? Wow. Ok...well glad I'm not alone. They swore it was pressed all the way on so I'm not really sure what to do either. 10mm is a lot. The MPHAS manual states they shouldn't be more than 5mm different from side to side. I know the driver side sits higher by default but...that's almost 1/2" I've been driving (about 1,500 miles now) so if weight was going to press it further down, it have moved although I don't exactly know if there's a certain point where the strut becomes "thicker" where it can no longer slide down any further.
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      06-18-2018, 11:26 AM   #6
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Just get the car corner balanced. Perches are almost never even when the car is properly 50/50 cross-weight balanced.
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      06-18-2018, 08:07 PM   #7
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Went back to the shop, found the real culprit. The chassis on this car is so stiff man...

Anyway the rear passenger side spring was not installed properly...



Fixed it and now the perches are adjusted to about 3-4 threads from each other. Completely acceptable.

This installation took 4 passes to be done right...brutal...but all good now.
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      06-18-2018, 11:37 PM   #8
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Nice. Glad you finally got it sorted out! Now go enjoy your ride!!
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      06-19-2018, 01:02 AM   #9
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Quote:
Originally Posted by knightarmor View Post
Nice. Glad you finally got it sorted out! Now go enjoy your ride!!
Yes, finally. Thanks!
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      06-22-2018, 07:09 AM   #10
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Quote:
Originally Posted by goaty View Post
Went back to the shop, found the real culprit. The chassis on this car is so stiff man...

Anyway the rear passenger side spring was not installed properly...



Fixed it and now the perches are adjusted to about 3-4 threads from each other. Completely acceptable.

This installation took 4 passes to be done right...brutal...but all good now.

How can this affect the height of the front perches.
I am redoing mine this coming week.
pulling of front suspension to double check everything as well.

MY rear is installed correctly and I have triple checked this.

glad yours is all sorted
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      06-22-2018, 09:45 AM   #11
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Quote:
Originally Posted by whoop_ass View Post
How can this affect the height of the front perches.
I am redoing mine this coming week.
pulling of front suspension to double check everything as well.

MY rear is installed correctly and I have triple checked this.

glad yours is all sorted
You'd be surprised. This chassis is so stiff and every corner can influence the other. This one was sitting higher and pushed the front/driver lower. Not sure how it just did. Once they re-seated it the front/driver sat lower.
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      06-22-2018, 02:36 PM   #12
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Quote:
Originally Posted by whoop_ass View Post
How can this affect the height of the front perches.
I am redoing mine this coming week.
pulling of front suspension to double check everything as well.

MY rear is installed correctly and I have triple checked this.

glad yours is all sorted
Quote:
Originally Posted by goaty View Post
You'd be surprised. This chassis is so stiff and every corner can influence the other. This one was sitting higher and pushed the front/driver lower. Not sure how it just did. Once they re-seated it the front/driver sat lower.

Think of a table with one shorter leg; the leg diagonal to the shorter leg will be affected.

IMO, 3-4 turn discrepancy is unacceptable to me. If it is installed correctly, it should be exact (unless you're corner balancing).
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      06-22-2018, 02:56 PM   #13
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Quote:
Originally Posted by exo-shell View Post
Think of a table with one shorter leg; the leg diagonal to the shorter leg will be affected.

IMO, 3-4 turn discrepancy is unacceptable to me. If it is installed correctly, it should be exact (unless you're corner balancing).
100% agreed when i had stock suspension car was with in 1-2 mm in terms of measuring each wheel to fender very little variation between left and right.

no I understand how this works Exo.
but on my car the left side front perch is 10mm higher on the damper.
also even if they were not press fitted properly, surely with the weight and pressure of driving (bumps etc) it would sag a bit to match other side.

The Perch is by no means screwed onto the Damper.
very odd.
going to strip the whole lot and redo it over :-(
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      06-22-2018, 03:12 PM   #14
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Quote:
Originally Posted by whoop_ass View Post
100% agreed when i had stock suspension car was with in 1-2 mm in terms of measuring each wheel to fender very little variation between left and right.

no I understand how this works Exo.
but on my car the left side front perch is 10mm higher on the damper.
also even if they were not press fitted properly, surely with the weight and pressure of driving (bumps etc) it would sag a bit to match other side.

The Perch is by no means screwed onto the Damper.
very odd.
Some times the friction of the perch on the shock body is stronger than the weight pressure the car will put on that corner. So there is a good chance the perch won't "sag" down into the correct position if it wasn't seated properly to begin with.

If it did get down into the correct position to after driving, then great. But it's definitely NOT the way an installer should justify not installing the perch correctly from the get go.

It makes me upset at BMW Service Departments because a lot of people go to them for this install and pay a lot of money. But in actuality, the BMW Service folks are probably some of the least experienced in installing this type of kit.
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      06-23-2018, 12:27 AM   #15
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Quote:
Originally Posted by exo-shell View Post
Some times the friction of the perch on the shock body is stronger than the weight pressure the car will put on that corner. So there is a good chance the perch won't "sag" down into the correct position if it wasn't seated properly to begin with.

If it did get down into the correct position to after driving, then great. But it's definitely NOT the way an installer should justify not installing the perch correctly from the get go.

It makes me upset at BMW Service Departments because a lot of people go to them for this install and pay a lot of money. But in actuality, the BMW Service folks are probably some of the least experienced in installing this type of kit.

you spot on brother, that's why I am redoing it, I actually did the rear my self again as the adjuster was turning in the body and used some betalink to prevent this.
also If installed it I would of measured it and thought..WTF!!!
why is this lower than the other side and troubleshoot further, but as usual, dealers need to get through many cars and it's a big rush rush
I will def update once I strip and reinstall it, what a ball ache.
Do it right the first time damit!!

customer will never notice
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      06-25-2018, 02:29 PM   #16
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Here's the measurements of the perch from both the driver and passenger side. We leveraged a block pressed against the bottom of the strut to get a more precise measurement. They were literally identical:



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      06-27-2018, 03:59 AM   #17
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[QUOTE=goaty;23374746]Here's the measurements of the perch from both the driver and passenger side. We leveraged a block pressed against the bottom of the strut to get a more precise measurement. They were literally identical:



[/QUOTE

great thanks for the pics
so before your measurements differed?
I have 10mm difference between left side and right :-(

Last edited by whoop_ass; 06-27-2018 at 04:08 AM..
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      06-27-2018, 06:46 AM   #18
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[QUOTE=whoop_ass;23382660]
Quote:
Originally Posted by goaty View Post
Here's the measurements of the perch from both the driver and passenger side. We leveraged a block pressed against the bottom of the strut to get a more precise measurement. They were literally identical:



[/QUOTE

great thanks for the pics
so before your measurements differed?
I have 10mm difference between left side and right :-(
Honestly, I never measured I just assumed that since there was such a heavy difference from side to side that they most certainly had to be off. I was wrong. They're identical. I even went in with the little slab of metal they used to measure to ensure they weren't "tilting" it to favor the same measurement and it's square. The perch that is pressed on to the strut couldn't go any lower and sat flush with the tool provided with the kit (the heavy sleeve thing).
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