Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Front steering geometry

I have an ARP4, coils on the back but standard sliding pillar setup on the front which has very little self centring, which I would like to increase just slightly.

Does anyone know how I would go about changing the castor angle to achieve this please?

Paul

Not much possibility, as far as I know. The self centering/castor angle is dependent of the kingpin inclination angle, as I suppose you know. I cannot see how you could change this without indulging in some major surgery. So I think it is inherent in the Morgan design. But strange as it sounds, my car is much more self-centering after I fitted PAS. I cannot explain why, there should be no power centering the wheels. But that is how it is. Of course, fitting PAS IS major surgery....

I found that increasing the TOE in a “tad” helped the self centring a bit. However in mitigation the factory had made a “ pigs ear” of the set up anyway. But worth a try. Easy to do & easy to return.

I understand you need to alter the angle the cross frame bolts to the chassis to alter castor. Not for the faint hearted!

I suspect that Simon (SiFab) of these pages will be able to advise. Also, I vaguely remember Cain of Wolf Performance posting something on his Instagram feed regarding adjusting the geometry of the front end.

Thanks for your comments all, it looks as if I might have to take some professional advice on this or just continue to persevere with marginal self centering. BTW Robbie, my car was fitted with power steering from new, so maybe it would be even worse without it?

Contact Cain at wolf performance he does it all the time.

I am wondering how many miles have been covered so far, and if the steering has been set up properly for your particular Morgan.
If it's set up well, and properly greased (sliding pillars not too tightly fixed within their bushes), there is self centering - albeit not overly so. The point being that a Morgan is a beautifully set up design which takes a while to be fully appreciated.
Personally speaking the first impressions I remember having of my 4/4 were not A1 at first. Because of misalignment (excess toe in), worn sliding pillars due to poor care, wheels not balanced etc.
Not every garage mechanic is up to speed on these machines and mine came with a complete "service history", (supposedly) undertaken by a major morgan agent and having only covered 7k miles.

I suggest a carefull overhaul and appraisal of the existing steering geometry before tampering with the steering geometry. Only then, try to get at least ten thousand miles on the clock before passing judgement. It takes that long to become self attuned to the characteristics of the traditional Morgan.

Because so many under-use their Morgan, only the few who do put them to regular use become truly familiarized

Thanks for the Cain suggestion, I have also been recommended to him in a PM as well, only trouble is he is on t'other side of the country from me in Zummerzet. Tim at New Elms is far closer, is he as good?

Graham, some good points and in the past 5 years I have done about 11,000 miles now, which are all summer use, so not quite as little use as the number might suggest.

My two problems on set up are that a little, with the emphasis on little, more self centering would be useful, but just as important is making the thing safe on a bumpy road at speed. We have some great, relatively empty B roads here, but they are bumpy, at anything approaching the National Speed Limit the car is all over the place. Not as bad as the 2012 Three Wheeler admittedly, but still requiring much concentration. Now, I'm not absolutely certain if it is bump steer, as it was on the MTW or just hard suspension not coping with the roughness. So, a little more self entering might help keep it straighter as well as helping get the steering straight, exiting sharp corners at low speed etc.

Paul, Cain is the master at steering and suspension he manufactures improved parts and sets up race cars.