Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing 2016 Roadster steering clonk..

I’ve been in the garage and “think” I know what’s going on with the “clonk” or “click”..
2018 4/4 with 3,500 miles. Sat on its wheels. Wife rocks the steering wheel while I lie under the front with hand on the rack’s central L shaped bracket … the one the attached to the front of the rack’s central tube and which holds the inner tie rod bearings.
Very slight but tiny vertical movement just discernible at the L shaped bracket. Not really visible but just “feelable”.

I think this is a feature of the Morgan’s rack design where the tie rods come off the L shaped bracket that is bolted to the front side of the rack’s toothed rod. There has to be a very slight running clearance (not wear) between the rack teeth and it’s pinion otherwise it would be stiff. Also it will be a feature of the pinion teeth (normally) being helical and the way they mesh with the rack’s straight teeth. So, the toothed rack rod may have a tiny bit of rotation possible wrt the pinion. The tie rods are unlikely to be absolutely horizontal all the time. Mine, sat in the garage today, both had a very slight but discernible upwards inclination. On turning the steering wheel with the tyres on the ground the longitudinal force along the slightly inclined tie rods will result in a resolved vector component in the vertical. So, turning the steering wheel will result in small resolved vertical forces on the L shaped bracket. This could perhaps move the rack bar within the very small range permitted by the running clearance between the pinion teeth and those of the rack’s toothed bar.
If the car is off the ground and the wheels free to turn, the forces would be diminishing small even though the tie rod angle may be greater. With the car on the ground my bet is that if you load up the front suspension to increase the tie rod angle (heavier engined Morgans) the “click” would be more noticeable.

I think this effect would not be seen with a normal rack where the tierods come straight off the rack ends as the vertically resolved force would not be applied in a way that would rotate the rack’s toothed bar.

Bit of schoolboy vector analysis there but does that sound logical or otherwise?

Basically no lost steering movement, unless rack and ball joints truly worn, and no reason to worry I think. I expect they will all do it a a consequence of the rack’s design.