Rear caster adjustment

ScoobyMoji · 03-04-2021, 07:24 AM

Hi guys

just noticed the rear passenger wheel is moved forward by about 0.2 inches when compared to the driver's rear.

Car did have the rear diff replaced under warranty and wheels aligned before the New Year.

I'm thinking:

1. Could bmw have removed the rear subframe when replacing rear diff and did not align it properly during reinstallation of 4 bolts resulting shift in caster?

2. The car's Toe is way off?

Oddly, the car drives straight

First pic is left rear. Second is right rear. measurement in cm (apologies!)

chief1richard · 03-04-2021, 08:54 AM

Quote:

Originally Posted by ScoobyMoji

Hi guys

just noticed the rear passenger wheel is moved forward by about 0.2 inches when compared to the driver's rear.

Car did have the rear diff replaced under warranty and wheels aligned before the New Year.

I'm thinking:

1. Could bmw have removed the rear subframe when replacing rear diff and did not align it properly during reinstallation of 4 bolts resulting shift in caster?

2. The car's Toe is way off?

Oddly, the car drives straight

First pic is left rear. Second is right rear. measurement in cm (apologies!)

You can't align a car by going with measurements from a fender. They are aligning the suspension, not the body. It may be spot on. You say the Toe is way off. Have you measured it?

ScoobyMoji · 03-04-2021, 09:12 AM

Haven’t measured it. So it could be normal?

Car has never had an accident.

Thinking I should just let this one go

chief1richard · 03-04-2021, 09:28 AM

Quote:

Originally Posted by ScoobyMoji

Haven’t measured it. So it could be normal?

Car has never had an accident.

Thinking I should just let this one go

You are the only one that will ever notice. Very few things in life are perfect.

ScoobyMoji · 03-04-2021, 09:38 AM

Thanks bud

Just one thing I could think of is the tire guy that came to plug the rear passenger tire had lifted that side off the ground and plugged it the without removing the wheel.

Saw him going at it pretty hard lying down to push that plug in, but surely could not have bent any arm?

Daytona_550 · 03-04-2021, 11:39 AM

Quote:

Originally Posted by ScoobyMoji

...and plugged it the without removing the wheel...

Unlikely that he bent an arm but be careful with that tire plug if he didn't patch it from the inside.

https://www.tireindustry.org/tire-ma...ce/tire-repair

MR RIZK · 03-04-2021, 06:38 PM

Get in on a wheel alignment machine and pull up the display where it shows the setback and diagonal measurements. This will help with showing the squareness of the car.

NISFAN · 03-05-2021, 11:22 AM

The diff removal doesn't involve removing the rear subframe. But even if it does, there are squared shaped pieces that align it perfectly, so unlikely that the subframe is not square to the chassis.
What is more likely is that in the process of a wheel alignment, the wheel position was distorted. The rear is a 5 multi link system, so there might be a few ways to end up with the correct camber and toe. If that makes sense?

ScoobyMoji · 03-06-2021, 03:53 AM

Cheers for that

It would be very comforting to know that toe and camber could distort the wheel position.

The guy that was reaming the hole in the tire pretty hard while lying down. The position of the hole of the tire was at the back of the rear tire, so he was exerting all the force from that point. Could he have moved the wheel forward by slightly bending one of the suspension components? I myself doubt it is possible for human force to bend control arms, but he was rather stout.

03-04-2021, 07:24 AM	#1
ScoobyMoji New Member 6 Rep 14 Posts Drives: M2 LCI & brz Join Date: Feb 2021 Location: TH iTrader: (0)	Rear caster adjustment Hi guys just noticed the rear passenger wheel is moved forward by about 0.2 inches when compared to the driver's rear. Car did have the rear diff replaced under warranty and wheels aligned before the New Year. I'm thinking: 1. Could bmw have removed the rear subframe when replacing rear diff and did not align it properly during reinstallation of 4 bolts resulting shift in caster? 2. The car's Toe is way off? Oddly, the car drives straight First pic is left rear. Second is right rear. measurement in cm (apologies!) Attached Images
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03-04-2021, 09:12 AM	#3
ScoobyMoji New Member 6 Rep 14 Posts Drives: M2 LCI & brz Join Date: Feb 2021 Location: TH iTrader: (0)	Haven’t measured it. So it could be normal? Car has never had an accident. Thinking I should just let this one go
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03-04-2021, 09:38 AM	#5
ScoobyMoji New Member 6 Rep 14 Posts Drives: M2 LCI & brz Join Date: Feb 2021 Location: TH iTrader: (0)	Thanks bud Just one thing I could think of is the tire guy that came to plug the rear passenger tire had lifted that side off the ground and plugged it the without removing the wheel. Saw him going at it pretty hard lying down to push that plug in, but surely could not have bent any arm?
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03-04-2021, 06:38 PM	#7
MR RIZK Major 758 Rep 1,336 Posts Drives: AW M2C Join Date: Mar 2013 Location: Australia iTrader: (0)	Get in on a wheel alignment machine and pull up the display where it shows the setback and diagonal measurements. This will help with showing the squareness of the car. __________________ Previous Rides: 13' 135i, 08' 130i, 03' HKS Turbo'd 350z, Modded GC8 WRX, NA MX5
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03-05-2021, 11:22 AM	#8
NISFAN Major General 3489 Rep 9,709 Posts Drives: BMW M2 Join Date: Aug 2012 Location: Bedford UK iTrader: (0)	The diff removal doesn't involve removing the rear subframe. But even if it does, there are squared shaped pieces that align it perfectly, so unlikely that the subframe is not square to the chassis. What is more likely is that in the process of a wheel alignment, the wheel position was distorted. The rear is a 5 multi link system, so there might be a few ways to end up with the correct camber and toe. If that makes sense?
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03-06-2021, 03:53 AM	#9
ScoobyMoji New Member 6 Rep 14 Posts Drives: M2 LCI & brz Join Date: Feb 2021 Location: TH iTrader: (0)	Cheers for that It would be very comforting to know that toe and camber could distort the wheel position. The guy that was reaming the hole in the tire pretty hard while lying down. The position of the hole of the tire was at the back of the rear tire, so he was exerting all the force from that point. Could he have moved the wheel forward by slightly bending one of the suspension components? I myself doubt it is possible for human force to bend control arms, but he was rather stout.
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