Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Lumpy steering

What I didn't realise for a long time was that the cars with damper blades have more castor than later cars. When I fitted mulfab bearings to my Roadster, the steering feel was transformed. Also bear in mind that my Roadster originally had Devol bushes, but the first owner had a major strop with MMC, and he claimed that the bump steer was dangerous. He demanded the later stubs, where the track rod ends were repositioned below. He had that done, so the stubs got bronze bushes as the upgrade but he had to pay. So after I fitted Mulfab bearings, the steering became finger light. No way you would need power steering, but also a lot of feedback on the road. I discussed this with Keith at BHM, and he advised me to fit a damper, which I did. A damper suggests that it would stiffen up the feel, but it doesn't. All it has done is eliminate feedback. There are those who rubbish the damper, and yet my hands on experience is that it was a huge improvement to feel. Make of that what you will.

Before I knew about the reduced castor, I assumed that fitting Mulfab bearings to my 2016 GDI would have the same effect on steering feel. This Morgan already had the MMC steering bearings, but the Mulfab bearings are way more rubust. I also fitted the Wolf lower bearings and I expected a transformation. It hardly made any difference. That can only be down to the reduced castor, and despite narrower wheels and tyres, my Roadster steering is way better than the GDI.

I always thought it was the other way round? As I understood it the early cars with steering boxes had steeper head angles, which although gave very light and precise steering, did leave the cars prone to steering shimmy or the renowned "St Malvern's dance" if the damper blades weren't set up correctly. Certainly my steering box car wobbles like a wobbly thing if my damper blades aren't adjusted correctly

With the change to steering racks the head angle was increased, (I think to 8 degrees) giving a longer trail - more stable steering with a more planted feel. When the wider tyres were also fitted it rendered the damper blades unnecessary.

To my mind a steeper head angle gives a shorter castor distance and a shallower angle a longer castor?

Well it was a combination of changes. Firstly the steering box cars had straight or square cross heads and positive camber to lighten the steering. slowly from their racing experiences the camber was straightened out to run neutral and then eventually negative and a greater caster angle was introduced. Toe was also played around with to try and keep the car from busy steering too. The older cars were always going to be harder to smooth out the steering hence the introduction of the damper blade.

I suspect that the castor angle has changed a few times to be honest. I was informed that it was reduced around 2006 when the damper blades were dispensed with. That was also around the time that the Devol bushes went and the stubs had the track rod ends moved from top to bottom on the steering arms.

All I can say is that castor return us much stronger on my 05 Roadster than my 16 GDI. Its very obvious.

When I was 17, I bought a scrap 105e, for the engine to fit into my scrap 105e. The year was 1970, and £22. On the front lawn, I stripped that to a shell. Cut the shell up using a hacksaw, and the binmen dropped by with a flatbed, and took it away for a tenner.

The shed became my 105e stores. That Anglia had a steering damper. They suffered bad wobble. The result was a small hydraulic damper. In the hand it was stiff. It must have been for another application because I doubt anyone would have tooled that up for such a use. Anyway it fitted to the steering arm with a U bolt, and onto the inner wing panel with a bracket and a couple of bolts. Just like with Morgan, no change to steering feel, but the wobble was gone.

In your three posts above Dave you don't mention the Quaife rack damper issue you found. Please correct me if I'm wrong but I believe you found the nylon yoke/plunger had expanded to the point it had seized in the hollow threaded adjuster such that it's spring loading had no effect on the rack, although not sure on which of your Morgan's. This issue was brought to light on Talk Morgan by Heinz I believe although relatively recently. The usual sanding down and re-adjustment correcting the situation.

Whether it was discovered on your Plus 4 or Roadster is almost irrelevant as I'm tempted to suggest it may have saved your need to fit an external damper to your Roadster which would simply hide the effect of an issue on the rack itself, given it would manifest similarly to that which caused your initial concerns following fitting steering bearings.

In my own case on 3.7 Roadster the very first difference noticed after checking and re-adjusting rack was slightly stiffer steering coupled with calming of the light lively steering previously encountered which had almost imperceptibly over time increased skitishness over bumps.

FWIW I also have the Wolf lower steering bearings which gave immediately lighter steering, albeit with Morgan's own upper bearings, however I also have a nominal 13 inch (actually closer to 12 inch) MotoLita steering wheel. When experimenting by pulling the EPAS fuse I found the steering heavier at all legal speeds but particularly during parking such that the fuse was quickly replaced. This with 205 tyres on 7 inch rims and I believe the heavier 3.7 engine. This probably explains why MMC made the Denso EPAS standard on the 3.7 Roadster around 2018 rather than an option.

It was the Roadster. Looking back, the damper job was 2017. From memory the nylon plunger job was about 3 years ago. So was not really an issue at the time I did the damper add-on. I rarely take advice , but when Keith at BHM gives me the nod, I listen. That's why I did that damper upgrade. I suspect that it would be a different feel with reduced castor and power steering. So I can only report on my own experience.