MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Solidmount Crossmember

Just a thought - As the front suspension arms have a rubber mountings at one end, why is the crossmember also rubber mounted and has anybody tried mounting it solidly to the chassis ... Cheers .. Andy
A Hastings

NVH. And why would you want to?
Paul Hunt 2

All rubber mountings will move albeit a very small amount. I wondered whether there would be any advantage in terms of 'feel' and disadvantage in terms of increased vibration/roadnoise. I cannot think of many other sports cars with this type of mounting system ...
A Hastings

The reason for the rubber pads at the front crossmenber is to provide the weakening of the chassis legs due to vibrations and also damping road noise from the front that would also lent to cracks in the mountings of the stearing gear.

If it would not have been necessary, Abingdon would not have fitted these isolating blocks.
Do not remove them for road traffic!

Safety Fast!

Ralph
Ralph

Thanks for your comments Ralph - I accept that there was a reason for fitting the pads, but if this was purely for reducing road noise, would their removal show any benefit in roadholding?
I think the steering rack bracket cracking that you mention is probably more to do with the fact that they could just cope with the forces exerted by the standard 165 section tyres but with modern wider and grippier tyres, there is too much bracket flex especially at low speed manouvering.

Cheers .. Andy
A Hastings

Andy, Its normalo in most cars for the unsprung assemblies to be double insulated from the chassis to provide comfortable and quiet running. I think if you remove them you will be subjected to considerably increased road noise and discomfort as well. Quite frankly I wouldn't do iy.
Iain MacKintosh


In the book "MGB, Including MGC & MGB GT V8", David Knowles wrote that "Excessive noise was found to be caused by an experiment to weld in the front cross-member (set out as ADO23/820, dated 6 October 1961), and in the end the cross-member was bolted in conventionally."

Keep in mind that MG was almost certainly testing with bias-ply tires, which had relatively stiff sidewalls.

Removing the pads should improve roadholding, but not by very much. If you want to experiment with stiffened mounting, keep in mind that there are two different stiffnesses of polyurethane pads available. (I installed the black ones Moss offers.)

Some of the modern aftermarket MGB front suspensions, including the excellent "Fast Cars" one, mount metal-to-metal. I've driven several Fast Cars suspension equipped MGBs, and I can testify that they have a very quiet and smooth ride.
Curtis

Andy

You should also be aware that the mounting studs for the crossmember are a fixed length with shoulders which fit into recesses in the front chassis legs, this ensures that the insulation pads cannot be over compressed and in a way to upset the front suspension geometry.

To solid mount the crossmember you would have to make up some new mounting studs or modify the lower end of the existing ones, to allow the crossmember to be located to the chassis at the correct torque setting.

Not worth the trouble in my opinion. If you have the crossmember off I would recommend fitting poly pads for a slightly firmer location and possibly a Brown and Gammons de-castor kit to reduce the weight of the steering at parking speeds and reduce the loading up when cornering at speed.

Kevin
Kevin Jackson

This thread was discussed between 10/09/2007 and 11/09/2007

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now