Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Rear Thrust Angle

Sounds like you need some anti-tramp bars. I put them on my 2005 S1 Roadster and they have made a lot of difference.

I have anti-tramp on both sides. The diff was bashing into the tool tray every time you hit the gas hard. The anti- tramps stopped that.

Good discussion of thrust angle here: http://www.brakeandfrontend.com/alignment-specs-thrust-angle-and-setback/

Allen
'69 4/4

interesting, thank you for posting

My Physics teacher taught us that the Angle of the Dangle was proportional to the lust of the thrust providing the urge is constant.

Ohms law it turns out!

Why do you ask?

As regards the use of rear axle anti-tramp bars, on a Morgan these are used to prevent the rear leaf springs 'winding up' when accelerating quickly from a standstill and partularly noticeable when sticky tyres are used and race conditions. Under such circumstances, the springs allow the axle to rotate on its axis with the forces changing the spring shape from a 'flat U' to that of a 'flat S'. With axles fitted with a limited slip differential (LSD) this action will also occur side to side as each wheel grips then breaks traction. Definitely not good for differentials!

I am asking so I can compare my reading with what ever is the normal setting at the factory. This has nothing to do with anti tramp

The rear axle shuld be 90 Degrees to the mid line fore/aft of the chassis. Though given all the flexing involved in practice I doubt that this is maintained. Additionally I'm not sure what the tollorance on spring mounting points are or allowable bushing deflection.

I'm guessing if you have to ask - you have a problem of some sort - Classic Morgan set-up is a bit of a blunt tool then you get to this level of fidelity.