Subframe not aligned correctly causes alignment to be off

[hostler]

A little over a year ago I've had my local garage change replace the gearbox. They removed the subframe for this job. About 6/7 months after that I took the car to a proper alignment shop (with a Hunter system if I'm correct) for some more camber.. After aligning the car they told me there was a small difference in the right/left side of the car. There was a slight difference in castor left to right.

I'm wondering if there's any play in the subframe. Would it be possible for the shop to not have properly aligned the subframe and causing the difference in castor?
I've never properly aligned the car before the work on the gearbox so I'm not sure if it's just fcked or that the subframe just isn't aligned properly (or maybe the subframe is bent or something).

Sorry if this is posted in the wrong section.

 

[Goti172]

Subframes are bolted to 4 holes so i cant see it being "mis-aligned"

 

[STEVE.M]

I`ve spent 35 minutes thinking about this, and have come to the conclusion that what you don`t know won`t hurt you.
Broadly speaking, that is within the manufacturing tolerances of the wishbones, one front wheel being 1mm forward of the other.

 

[hostler]

Thank you both for your replies.

Yes, it might be within tolerances, but the steering wheel moves ever so slightly when braking extremely hard on a straight road. This is not noticable on track or during normal driving. I never noticed this before the box was changed but it could've always been there of course. I've read stories about the wheel moving because of play in the wishbone bushings but they've all been powerflexed so I doubt that would cause it.

So you guys think there's no possibility that the subframe could be misaligned? I thought there might be some space around the bolts that bolt up the subframe to the car which would explain this.

I could ofcourse just bite the bullet and replace the wishbones, since I'm also unsure which side would be the "correct" one.

 

[hipwell]

What do you mean by moves?
Shakes? Or pulls the car to one side?

If it's the first then id be checking all brake sliders and maybe changing the disks.

 

[bloke]

check it's got same wishbones on, seen them with one older and one newer one on.

 

[hostler]

What do you mean by moves?
Shakes? Or pulls the car to one side?

If it's the first then id be checking all brake sliders and maybe changing the disks.

Just did the brakes and did the sliders so it can't be that.

The wheel turns left slightly when braking extremely hard but car goes straight. When you hold the wheel straight the car pulls right.

I think this is related to the difference in castor.

check it's got same wishbones on, seen them with one older and one newer one on.

They seem to have the same amount of wear/rust on them. Doubt they are different tbh.

 

[STEVE.M]

Thank you both for your replies.

Yes, it might be within tolerances, but the steering wheel moves ever so slightly when braking extremely hard on a straight road. This is not noticable on track or during normal driving. I never noticed this before the box was changed but it could've always been there of course. I've read stories about the wheel moving because of play in the wishbone bushings but they've all been powerflexed so I doubt that would cause it.

So you guys think there's no possibility that the subframe could be misaligned? I thought there might be some space around the bolts that bolt up the subframe to the car which would explain this.

I could of course just bite the bullet and replace the wishbones, since I'm also unsure which side would be the "correct" one.

There are 2 dowels that are inbuilt into the rear of the subframe, so misalignment is not really possible.

Bump stop steering, unmatched spring rates, damping and tyres tram lining on anything other than a perfect surface are all possibilities, but there is meant to be some intelligence making steering corrections.

 

[hipwell]

Just did the brakes and did the sliders so it can't be that.

The wheel turns left slightly when braking extremely hard but car goes straight. When you hold the wheel straight the car pulls right.

I think this is related to the difference in castor.



They seem to have the same amount of wear/rust on them. Doubt they are different tbh.

Track rods?

 

[hostler]

Track rods?

Would not cause difference in castor though

There are 2 dowels that are inbuilt into the rear of the subframe, so misalignment is not really possible.

Bump stop steering, unmatched spring rates, damping and tyres tram lining on anything other than a perfect surface are all possibilities, but there is meant to be some intelligence making steering corrections.

Not sure what you mean with that last part.

The wheel turns on multiple surfaces so it must be related to the castor difference. The question now is what would cause this. I think the cheapest option would to just replace the right wishbone as the left one seems to be closest to the alignment results from others that I found on google.

 

[STEVE.M]

You can do anything you want with these, but it would be cheaper elongate the outer slot on the bottom ball joint.
http://www.pure-motorsport.co.uk/cl...nsion/clio-2-adjustable-wishbone-package.html

 

[hostler]

That's a very nice bit of kit.

but it would be cheaper elongate the outer slot on the bottom ball joint.

Clever. Might do that if it turns out to not be as simple as replacing just the wishbone. Thanks.