Front subframe alignment
Turbo Mini Forums

Hi,

While bolting my front subframe upto the top cross-member it looks as though the subframe doesnt sit concentricly to the holes within the shell.

I'm not using the sandwhich mounts that go between the subframe and shell in order to raise the subframe (to gain body lows withing sacraficing suspension jazz) But of course.

I have modified the front subframe, removing the rear section and replacing with CDS. Thinking I had inadvertently pulled the frame in welding in the new bars I have bought a 2nd hand front subframe, which appears to measure the same.

Unfortunatly, i dont know if this issue was already there before I stipped it down, not something I thought to look into.

Has anyone came across this sort of issue before?

Thanks,

Dave.

David.

Considering what the car was originally used for and who previously owned it, I wouldnt be surprised if it had hit a tree or two in its past. I know the girls often ventured into the scenery, at least early on

Have to seen the jig data for the mini?

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Edited by Sprocket on 2nd Aug, 2015.

It is something I had considerd when I was looking at bolting it up, However the bulkhead hadnt been modified as far as I could see (at least before I put the turbo box in place), so any change in width doesnt match up to what i'm seeing looking down the bolt holes.

Really should have started with a new shell before faffing around with this rebuild :/

David.

My shell measures as per the dimensions on Sprockets post, it's 770mm between centres (385mm x 2), we built the jig for my tubular subframe to this dimension as well

Cheers

I appear to be about 4mm out, as best that I coud see with my shonky tape measure, across the bulkhead.
Not able to measure the subframe between centres as the subframe is currently bolted up with engine sat into it.

Is there any way to measure across the suspension points for the top and lower arms? and then any way to measure to make sure they arent biased one side? sorta like /---/
Although it hasnt been tracked, it looks like one side of the lower arms has needed to be wound more than the other, another reason for me maybe wanting to look to use a different subframe.

David.

With the engine sat in not easy to measure anything properly.

Measuring say the top arms centre to centre is easy enough as there is a clear line of sight (without the engine) but what is not so easy is being able to reference a reliable centre line to establish if some things off to one side.

I've done it several times but is a PITA and takes ages;

Get the shell level, fore /aft and side to side on a level / flat surface

Fix some board / card on the floor below what you want to check

Using a plumbob drop a mark down onto the card for each centre you want to check, sometimes you need to put say a long bolt into a suspension point to get into a position where there's a clear path for the plumbob down to the card.

Once you've done it for all the points..... Do it again to check how much variation your measurements have

For each symmetrical pair of points you can create a centre point and hence a centreline - it's far from perfect, especially if the whole of one side has been pushed in, but generally you can see if all / any of the centre points are on the same centreline/s. PITA

Ideally find someone with a FARO arm but establishing a real centreline is exactly the same for either method

Probably much less agro to borrow another frame and see if it fits better / if suspension arms become the same length.

I do have the spare subframe I was reffering to in the first post :/ Dont really have space or resources/knowhow to go about making sure the shell it straight, and if I did its a few years too late with the work i've done to the car.

Might just keep it as an un-hacked, standard subframe, and not replace it was CDS and refit the standard top mounts... all tried and tested then at least.

Seems a lot of minis crab down the road anyway without too much detrimental handling effect, hope it still goes ok when its ready to go

David.