Prop Shaft Rubbing / Suspension Upgrade

[cdow]

My prop shaft rubs on the tunnel going over bumps/dips - it's always done it - but funnily enough has got worse over the years as the driver has got heavier!

It's now got to the stage with two of us in the car that it rubs most of the time, even on flat roads under acceleration for example.

Presumably there's a fundamental alignment issue that’s been there from day one, which may not be easy to resolve. I think the best course of action is to beef up the rear suspension to cope with the extra weight the car now has to cope with.

Has anyone got any suggestions as to the best approach to this, shocks/springs etc? (Suggestions that don’t include dieting and exercise please)

At present the car has the standard Marina 1.8 set-up with Spax adjustables that have been on the car since '84 (I’ve tried winding the screw in to make it harder)

[CABRIOBOB]

Re: Prop Shaft Rubbing / Suspension Upgrade

Check your engine and gearbox mounts are ok. Also you can fit anti-tramp bars from the chassis/under body to the rear axle which will stop the rear axle from moving side to side when hard cornering. check the prop is not catching the seat belt support bolts or rubbing through the brake pipes as this can happen.

[patrick.bramman]

Re: Prop Shaft Rubbing / Suspension Upgrade

When I first got my Roadster it did it but no more. The thngs I chaged were new shackle bushes, new engine and gearbox mounts and smaller lowering blocks so the rear ride height was increased (so I could go trialing but that's another story). Not sure which of these did the trick but it's fine now. Good point from Bob about the brake pipes, mine were very close so re-routed

[dogoncrazy]

Re: Prop Shaft Rubbing / Suspension Upgrade

I think you'll find that the propshaft flange on the rear axle is 'offset' of the centre line of the car, and that the tunnel is usually equally spaced either side of centre. Consequently propshaft is liable to foul on one side of tunnel given any sideways movement of axle. I 'adjusted' my tunnel/floorpans to give equal clearance either side of propshaft to prevent problem re-occuring.