Rear suspension lop- sided

[peters3103]

Hello all
My 61 Series 1 FHC is approx 1/2" lower on the left rear. This is when measured from the centre of the spinner to wheel arch on level ground. It is noticable looking at the car from the rear. The front suspension is set as per the factory manual and is level. I have tried swapping the rear shocks from one side to the other but no difference. The shocks are all fitted with the spacer at the bottom. The manual also list packing shims between the rear suspension and the body but I can't determine where they would be. It has been suggested to fit height adjustable shocks but that isn't really addressing the problem. Any advise would be appreciated.

Cheers
Peter

[mgcjag]

Hi Peter.....The ride height is affected by the springs a week one could be the problem....Also the amount of fuel in the tank....The shims fit between the IRS cage mounts & the body & will alter the centering of the cage & not its height....I assume your rear tyres are the same make/wear & the pressures are the same. Also if you are measuring to the wheel arch has the car ever had arch repairs making them a slightly different shape?...keep us posted ...Steve

[peters3103]

Hi Steve,
Thanks for the response.
It's obvious looking at the car from behind that it is lower on the left side. As mentioned I have swapped the shocks from side to side but no difference so that should rule out springs? The tyres are all the same size and same pressures, even with low fuel it is apparent and would only worsen with a full tank. Possibly when I put my 90kg bum in the drivers seat it would even up a bit! It's a frustrating thing that I can't seem to figure out. Any other ideas anyone?

Cheers
Peter

[wol916]

Hi Peter,
Just a thought but re fitted my IRS after restoration last week, I would think the V blocks could have an effect on ride height if the rubber has become perished.

Warren

[peters3103]

Thanks Warren,
I have looked at the V mounts and both sides look to be in good order and identical, however I will measure exactly. Interestingly from the front the car appears level and the measurements at the front both ground to wheel arch and from ground to wishbone pivot are equal.

Cheers
Peter

[mgcjag]

Hi Peter...check the camber angle of each rear wheel....this is altered with shims between the disc and the drive shaft...Steve

[peters3103]

Hi Steve,
I believe that the left rear wheel is running slightly negative camber and was told to remove 1 shim to correct it. Would negative camber in fact have the opposite effect and make that side higher? I will make this adjustment when I return from holidays. It will be interesting to see what difference it makes.

Peter.

[mgcjag]

Hi peter....note that the top bush on the shock should have a metal sleeve interted.....if one was missing it could have an affect ?.....because you swapped the shocks/springs over are you saying that the car is now higher on the opposite side....Steve

[PeterCrespin]

If a rear wheel had too much negative camber, removing a shim would make it worse not better.

The car needs to be weighed on all four corners or jacked up at a central point under he picture frame and then under the diff, in such a way as to reveal any lopsided stance on one axle at a time by having a longitudinal bar or narrow beam at some point between the jack pad and the car structure to allow side to side tilting.

The measurements need to be from fixed points as per the manual, although bodywork is a very rough guide and of course if it looks lopsided it is lopsided. Only by isolating one axle at a time can the true source of the issue be determined, since rear uneveness is affected by front uneveness and vice versa. If the rear left is too low and the car started off level, the front right should be suspiciously high.

As for correcting it, if you don't want to buy new parts then just pack the low side until it is the right height, assuming the front isn't the issue.

Pete

[kingzetts]

Removing a shim (they sit between the driveshaft and the diff output flange) will pull the top of the wheel further in towards the centreline so if the wheel is currently further out at the top than the bottom (ie currently running positive camber) this would slightly raise the ride height. But if you already have negative camber (and a correctly-set-up S1 E should normally have around 0.75 degrees of negative camber) then removing a shim will increase negative camber and slightly drop ride height.

BUT ...... the effect of one shim would come nowhere near correcting a half-inch difference in ride height, this is not your problem.

[peters3103]

Hi and thank you all for your responses. Apologies, the left rear wheel is slightly positive not negative as I incorrectly stated, so removal of a shim should correct this? I'm not to sure whether the left is low or the right is high, I must check my manual for the correct measurement. So many E Types seem to have different ride heights. Obviously on the front this is determined by the setting of the torsion bars but the rear must be dependent on spring length or the fitting of adjustable shocks. My shocks appear to have an alloy spacer at the base of the spring, perhaps if I remove these on the right side shocks it may drop the required amount to level the car. I will though firstly try to determine the cause. Aesthetically, I actually prefer the height of the left rear (low) side.

Regards
Peter

[PeterCrespin]

Your situation is not unusual. Many more LHD cars seem to take a set and ride low on the left side than RHD cars sit low on the right.