mk1-forum.net

Everything thing is tight and where it should be on the front and rear ends which makes me lean towards corner weights but I have no issues with the other cars which makes me think it`s a waste on time on a road car but the alignment has been checked so many times now it`s getting annoying.

I once bought a Rover mini Cooper on the cheap with loads of rusty panels and a short MOT and gave it " a good testing " on the 5 mile drive home.
It drove really well and I wasn`t hanging around, the next day I got it on the lift and both radius arms were shot with huge amounts of movement and it still handled better than this one !!

I think that we've pretty much exhausted all ideas I'm minded to suggest that it's an incurable fault inherent in the car. If everything is straight, correct, aligned, tight, up to spec etc etc then I'd suggest the next best thing is to break for spares or sell it I say!

Are the hub centres to wheel arch distances the same on each side of the car? If left is different to right then the shell may be twisted especially if any difference is reversed front to back. Alignment at wheel centre height can appear to check out ok even with a twisted shell. It’s not the easiest thing to check out but some ingenuity with a spirit level might reveal something.

D

Do you know the condition of the sills, floor, crossmember etc?

Peter Laidler wrote: ↑Wed Oct 27, 2021 6:20 pm On this subject – sort of, I recall that several years ago I wrote a tech article regarding the rear suspension and wheel alignment that put several myths to bed. One related to the rear track-in – or out – myth. Here’s a small exerpt of what I said relating to the myth of mini rear wheel toe-in or toe-out.. And it matches with just what the good Doc S says above…..

An’ annuverfing. While I had the opportunity to set up 4 rebuilt/modified rear rad/swinging arms up on Vee blocks on a surface plate, I was able to use a running DTI along the stub axles. And they were absolutely parallel to the radius arm shafts horizontally. Now, seeing that the 4 holes of the sub frame and mounting brackets are physically both accurately and horizontally aligned (and optically too…., try it with a laser light). That means/seems/appears to my non really scientific mind that the rear wheels will /MUST run parallel, WITHIN A STRAIGHT SUBFRAME regardless of what the workshop manual says.

So whatever the problem is, it shouldn’t be rear wheel castor. The problem might be a zillion other things, but if the rear sub-frame is straight with standard end brackets, then it won't be castor

Not sure I believe this Peter,

Yes, the stub axle and pivot shaft (hole) in the trailing arm are parallel. A well known Oz racer from back in the day once told me about a special tool used by his semi-factory team. Basically two rods welded parallel to each other on a piece of steel bar. One rod slid over the stub axle the other through the pivot pin hole at the other end of the trailing arm. If the car was badly curbed they would whip off the trailing arm and if the tool didn't slide into place, a new trailing arm was required.

However, if the factory dimensions require the inner and outer pivot pin holes to be perpendicular to the centreline and in single straight line from one side to the other (which it would seem that Peter is suggesting) then it would be impossible to have rear toe in - which all the factory manuals and specs say you should have???? And the factory alignment tabs can only ever produce toe out.... which seems to be a universal no no unless (for, say, competition purposes) you're looking for really twitchy handling. I've NEVER had a car that didn't need adjustment tabs to achieve zero toe. i.e. a line through the inner and outer pivot pin holes on one side will not pass through the holes on the other side. (Not that I've ever had a car that didn't have a factory rear subframe).

And of course it can't be castor. By definition the rear suspension can't ever have any ..... Or maybe its mote accurate to say that it will ALWAYS be zero...

Happy to be corrected...but

Cheers, Ian

Every Mini I have ever owned, has had toe in on the rear, between 1 and 2 degrees.....

I currently have 3 driveable Minis, all with original unmolested rear subframes, a 1961 Morris Woody, a 79 Canadian export Saloon, and, a 95 JAD Mini...

Unbelievably, they are all on their original pins and bushings, all have around 1.5 deg toe in........

I always take on board your comments BWA, Toe in, or out on a standard mini...... How, pray tell ? Given the facts relating to the sub frame alignment and parallelism of the radius arm shafts? Like I often say, I'm not the brightest ever engineering graduate in the box........, but I ain't bad enough to argue with basic physics

I have the Dunlop Tracking Gauge ( the one where you look down the tube to the reflecting mirror ) .. with a bit of licence it is just possible to use this system on the Rear of the Car . result is every road car i have had has a rear end toe in that shows up with the Dunlop system.. problem is it does not tell you if the rear end is aligned to the front end .. so if suspect & i do sometimes get that feeling it is not correct .. Then nothing wrong with setting up string lines down each side of the car & measuring in to the wheel rim edges front & rear.
Maybe a check the rear subframe tracking before you refit the built up rear subframe to the car .. something i have never done before but it should work

I don't agree with that Peter, How do you explain the fact that the workshop manual states that the rear camber is 1 degree positive and has 3mm toe in ? Every standard mini I've worked on has had positive camber and toe in on the rear.
If we accept that a long 1/2" inch steel bar will slide through all four holes of the subframe radius arm holes and is parallel to the ground then the only way to achieve the the factory camber and toe figures is that it's built into the radius arms. I've measured four different dry arms and they all have 1 degree of positive camber and 0.35 deg of toe in built into them.
When I set my car up with the standard outer mounts I had the standard one degree positive camber so i fitted the fixed position plus 1.5 deg outer brackets MS69 and I ended up with 0.6 deg negative camber. to reduce the toe in to 1mm toe in per side I fitted a 0.6 mm shim to the outer bracket.
One degree of camber equates to moving the outer pivot hole up by 4mm.
Have you ever measured the rear toes and cambers on your car?

Excellent procedure, and equipment

In MCR Cooper World this month Richard Pengelly provides a Technical Topic on Suspension etc;.. suggesting a simple way to identify Crabbing by using a Plumbob to be able to put a mark onto the floor to identify the central position of each 4 wheels .. then move car away from the area to measure diagonally across the wheelbase establish the cross distance front to rear and measure same again to the other side with the theory that these two cross measurements should be equal .. hence the cars front wheels are set in align with the rear wheels .. suggesting if not the car may crab when driven..
Richard does not give any acceptable tolerance to his dimension check.. but probably a simple way to check if a Car remains near enough wheel base aligned after any major accident or re-work to the BodyShell ..any others using this method ?

This makes interesting reading..
What would you recommend for nippy road use.
Tow, Camber etc front and rear..
D

Some great theories and advice here…..thanks.

Polarsilver wrote: ↑Fri Nov 05, 2021 9:59 pm In MCR Cooper World this month Richard Pengelly provides a Technical Topic on Suspension etc;.. suggesting a simple way to identify Crabbing by using a Plumbob to be able to put a mark onto the floor to identify the central position of each 4 wheels .. then move car away from the area to measure diagonal....

Or, find a flattish bit of concrete, splash some water in front of front wheels. Push car through water until back wheels have passed through the puddle (steering kept straight).

Front and rear wheel tracks will be obvious on dry concrete. Rear wheels won’t follow directly in the line of the fronts but any offset will be obvious.

Cheers, Ian

Better still, to eliminate all flexibility inherent with tyres AND to give you dead straight sides/edges, just cut 4 'wheels and tyres' out of some 3/4" shutter ply.

There......, exactly aligned with F and R hubs, eliminated the flexibility of the tyres and the measurement points are taken from JUST where you need to take F to R alignment and parallelism from.

Bolt 4x sheets together and cut and drill stud holes all together for simplicity and reasonable radial accuracy across the 4 'wheels'

I did it this way by accident and it's doing this that caused me to discover and later investigate that the rear wheels are parallel (oh yes they are....). In case you were going to ask........ I made some shutter-ply wheels to keep my S at least 'rollable' during the winter while refurbishing my wheels

I use one of these there quite useful..
D

https://www.ebay.co.uk/itm/DIY-Steering ... 635-2958-0