Front suspension overhaul

[Chazbee]

I am about to overhaul the front suspension on my 1968 tourer and intend fitting polyurethane bushes. ESM sell a set for less than £20 which seems cheap compared to EBay etc. - has anyone used them - are they OK.? Would you use polyurethane on both sides of the tiebar or fit normal rubber on the rear side as I think I've read somewhere on this forum? As well as changing the bushes I'm going to correct the near side ride height which is low by about 1,1/4 inches (a result of previous suspension work by others) - one spline down I think. I presume this will change the camber - if so,will raising the ride height move towards negative camber or vice versa.

[philthehill]

http://www.morrisminorspares.com/front- ... es-p830572

What ever poly bushes are used they will be much better than the Genuine BMC items.
The general consensus as regards the tie rod bushes is to use a rubber bush on the inner/rear side of the tie rod bracket and a poly bush on the outer/front end of the tie rod.
That will give firmness under braking and flexibility of suspension movement.
Raising the suspension will increase the negative camber of the front wheels.
The geometry of the Minor front suspension results when lowering the car to increases the positive camber i.e. the top of the wheel points outwards.
You may have to adjust the rear torsion bar adjustment plate (Pt No: AAA1852) to get the suspension spot on.
Use the measurements in the diagram below to set the initial suspension height.

[Chazbee]

Thanks for the quick and comprehensive reply! Have you any idea as to how many or part of a degree the camber will move to negative for a 1,1/4 inch raise in height?

[philthehill]

All I can state is that vehicles fitted with rubber top links and with the suspension set to the right height (as per the BMC wksp manual) the camber of the front wheels should be 1 degree negative.

[Mark Wilson]

I've just rebuilt mine, but not road ready yet so can't comment on how it has worked. I used the ESM polybushes and they look good quality and fit well, also used the rubber inner tie bar bush as suggested. Getting the tie bar back in place is always a struggle and I suspect using the harder poly here would make it even more of a challenge.

I was really pleased when I found the workshop manual diagram Phil has reproduced above. The unloaded "assembly position" dimension C (5 5/8") seemed ideal for my total rebuild with no reference markings. Pity there seemed to be no way to achieve this dimension without the damper arm hitting the bump stop. With hindsight I suppose I could have assembled the lower arm and torsion bar before fitting the top link? Anyway, I set it up with the damper as low as it would go and will adjust it once the car is loaded up with the engine, gearbox, wood frames and a few other weighty things! At least I know the T bar splines are well lathered in copperslip, so should be a fairly easy adjust.

Mark

[philthehill]

The 5 5/8" (14.3cm) dimension is meant to used to initially set the lower arm with the lower arm disconnected from the steering swivel and the lower arm has no other loading placed upon it.
As regards fitting the tie rod rubbers - I have never had any problem in fitting either the BMC rubber bushes or the rubber/poly bush combination.
My own solution was to get rid of the tie rod rubbers and fit a spherical joint sourced and adapted from a Mini adjustable tie rod kit.
Should only be fitted if the car is used on billiard table surfaces.
The picture below of the eye bolt has ESM red poly bushes fitted and a grease nipple to keep the bushes lubricated.

[Chazbee]

Thanks to all for excellent responses.