Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Re-adjusting SSL front suspension

I have recently been noticing what I can only describe as a slightly vague feeling to the handling and since I upgraded my engine I thought it would be a good idea to get that department sorted as well.

It seems to have crept up on me gradually and playing with tyre pressures didn't make much difference within the range I would normally work at. (between 21 & 25 psi)

I checked the tracking and that was fine at about 3mm toe in.

I did make some changes to the damper settings but in the end reverted back to my old standard settings. I tried 4 clicks up and down.

The vagueness seems to manifest itself on turn in and it was as though I could not turn in with any great precision and the car seemed to want to tighten the radius as though the back end was a bit loose. As a caveat to this I am still on the old Contis until Friday when I'm going to see Paul Harris to change to T Trac 2. But it was not quite the same feeling as having the backend lose grip.

To me it felt as though the car was rolling more into the bend so my thoughts turned to roll steer. The geometry of my track rods does mean that my car is slightly susceptible to roll steer but it had not really been noticeable until recently.

The roll at the front end of the Morgan is largely controlled by the relationship between the main spring and the smaller rebound spring and when you set up the SSL front end you adjust the spring platforms so you get the rebound spring just kissing the bottom of the stub axle after bouncing it a few times.

This is critical because if there is a gap above the rebound spring then you lose some of the roll control and I was very careful with that when I installed it about 5000 miles ago.

So I decided to recheck my adjustments and I now had a gap of about 5mm above the spring which I guess is to be expected after the initial bedding in.

I then got a mate to sit in the car and bounce up and down a bit as though on a bumpy road which is in effect matching the laden ride height as opposed to the unladen static ride height that I originally set the suspension up to.

After he stopped bouncing in the car, I checked the rebound spring gap and it was more like a 10mm gap which is way too much and does indeed allow the car to roll too much on initial turn in.

I readjusted the spring platforms to get a 0 - 1mm gap at laden ride height and I think it has made a big difference to the feel of the car on initial turn in without making it any harsher over the bumps.

So I think it is well worth checking the rebound spring gaps after a significant mileage and readjusting them, if necessary, as in my case I think it was affecting the handling.

BTW, If Peter Ballard is reading this and thinks I'm wrong, I would defer to his advice as I'm not a suspension specialist or indeed a qualified test driver but I'm convinced it has made a big difference.

Interesting.

I have a slight gap on the drives side rebound spring but not the passenger. I don't know much about Morgan sliding pillar suspension, mine is standard suspension not SSL. Could this gap be caused by a weak main spring on the drivers side?

How big is the gap? 1 or 2 mm probably won't make much difference but 10mm will.

Remember to bounce the car a bit first otherwise the front suspension stiction will probably make the driver side lower (i.e more gap) as that is the side you got out of last before you checked it if you the get what I mean.

Maybe 5mm gap but I will give the car a bounce and see if its any different! Thanks for the advice Bob

With the Morgan sliding hub suspension as you bounce up and down at the front the wheels try to move sideways. When stationary this make the front end seem totally rigid. Ideally you would have the front wheels sitting on a plate that is free to move side to side but if you rock the car backwards and forwards at the same time you would allow the wheels to move laterally and the suspension to settle in to the position you want.

Peter, I agree in principle but the kingpin inclination is only about 2 degrees so only about 1mm side movement for 30mm suspension movement.

With my skinny high profile tyres the sidewalls can easily flex that much at 21 psi and I haven't noticed the suspension locking up.

I can quite easily induce some bounce but it might be more difficult with wider low profile tyres where the sidewall has less movement.

Had a bounce up and down and got out of the passenger side and lo and behold a 5 mm gap on the passenger side rebound spring. The drivers side had closed up to maybe 2 mm.

So maybe more bouncing and waggling would settle both sides, but there was me thinking there was something wrong with the springs. You learn something new every day so still a very useful exercise for me Bob!
I'd like to upgrade to Rutherford springs but at 13,000 miles I was waiting until the kingpins needed looking at.

I did find my SSL bedded in & needed adjusting, just make sure you check the surface you use (garage floor usually) is level, don't do it on your driveway as a small incline will alter things like the rebound spring gap by a surprising amount

Bob, I expect Peter is busy, but your explanation sounds right to me

If you disconnect the front shock absorbers before bouncing you'll get quite a bit more movement.
I'd suggest what Suplex recommend and raise the front of the car on a trolley jack by 3 - 4 inches then quickly release the lowering valve of the jack. The car will then drop to the ground and bounce a few times on its springs. Do it a time or two and things should settle down nicely.