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MG MGB Technical - Works rear suspension

Does anyone know how the rear suspension was uprated from standard rear leaf springs and shocks on the works cars in the late 60's?

I understand the front lever arm dampars used uprated valves but the rear had 'adjustable damping'. Does anyone know what was used and what makes/ whether this is available as reproduction units etc. Thanks for your help
Dave Thirsfield

As far as I can recall, the works rear suspension was almost stock in appearance. No rear sway bar;
no poly bushings; no lowering blocks; no panhard bar; no anti-tramp bars. The suspension was
road tuned (using different springs) for each course and altered accordingly. If you examine archive
racing photos from the mid 60's era, you will also notice that the works cars were running at almost
stock ride height on certain race courses.

Not that the MGB could've benefitted from a fully independent & adjustable, coil-over suspension
setup - or that the good lads at Special Tuning were incapable of building such things - but this was
most probably because of strict FIA rules at the time. These rules specified that production cars must leave unaltered and stock certain suspension mount point locations, the number of mount points, as
well as certain stock dimensions, etc.. There were also FIA rules that deemed certain suspension
add-ons (ie: anti-tramp bars, tube shocks, etc.) - as illegal.

The adjustable damping on the rear shock was achieved via an adjustable valve. You merely replaced
the stock shock valve - then adjusted the damping with a flat screwdriver and hex lock nut (- much like
the adjustment on the engine tappet rockers). I used to see these valves offered in all sorts of
aftermarket parts catalogs (anybody remember: "MG Mitten"?), but now they're a rare item, especially
in the US.

On some works cars - the rear parking brake cables and linkage was modified so that there was a
brake hand lever controlling the left brake drum, and another brake hand lever controlling the right
brake drum. This allowed the driver to apply earlier braking power to the inside wheel while
negotiating a turn. These were on works (off-road) rally cars, mostly.

On some works cars - the rear springs had offset eyes in order to provide added clearance for wider
wheels and tires. When viewed from directly above, the springs resembled a stretched, lazy "W".
Very trick. The only car where I've actually seen these was on Joe Huffaker's Leyland-sponsored
E Production MGB back in the early '70's here in California. I think you can still get these in the UK
if you shop long and hard enough.
Daniel Wong

Dave-
The factory made a lot of neat stuff available for the racer, all of it proven on its own factory team racers. For example, they used a special rear leaf spring which afforded a 1 1/2" drop at the rear. When 6 1/2" wide magnesium wheels were used, it was necessary to use a special spring set and lowering block assembly. Daniel is right, this spring had offset eyes which allowed the spring to give more clearance at the tire while retaining its standard mounting points. A Panhard Rod was also offered (Sorry, Daniel, but the car was originally designed with one and the factory team liked them even if it didn't make it onto the mass-production cars). The reworked competition front damper was the and, as Daniel pointed out, competition valve assemblies were available. In addition, a nifty Teflon bearing kit was available. The most commonly used competition front springs were the. These little beauties would lower the front end 1 7/8" to 2". The most common front stabilizer bars were 3/4" and the 13/16". A rear stabilizer bar was offered to balance these. There was even a special reworked rear hub and axle assembly. Finally, a limited-slip ZF differential allowed equal power to both rear wheels while powering out of a turn. Of course, the list of these parts merely scratches the surface of what the factory would gladly sell to you if only you asked. Ah, those were the days!
Steve S.

Daniel and Steve,
While you're at it, does anyone know how the works rally cars would have been set up, say for the Monte Carlo Rallies? Or a good source of info and specs? The reason I ask is that the next 'B, after the Bugeye for my wife, will be a replica of the factory rally cars. Most likely an amalgamation of several since I don't want to go for an exact copy of one, and be wrong on some counts. I'd rather pick features from several, if need be, that meet my requirements for present day roadability, etc. and still appear and drive like a "typical" works car. I've looked at several books, including Knowles' and McComb's, and they really don't help.
Thanks, Wade
Wade Keene

My understanding has always been, and I'd be happy to see it verified or discounted, is that the works used to run the rear suspension soft. I think this was to aid traction, etc. I may be wrong, and I'd love to hear from someone who knew. I must do more research myself.

It's interesting, 'cos you talk to anyone who has played around with their rear end (ahem) and everyone has stiffened things up. RB springs on CB cars etc, or GT springs on roadsters.

I think the original thinking was that leaf springs are stiff enough, it was just the damping that needed fine tuning.

Am I right?
Michael Watkins

Michael,
Your thoughts on a soft rear end (on the cars) sound like that's what they'd do, judging from the appearance of the rears on some contemporary pictures as cars a re taking corners, etc. Not that that would be a real accurate way of telling how they set things up :) I have stock springs on my car and I wouldn't want anything stiffer on there. I believe they used higher springs, presumably front and rear, on the rally cars for clearance purposes. After seeing some pix of what conditions they used to run in and myself running the Missouri Endurance Rally a couple of weeks ago, I can see why.

Cambridge motorsport used to list adjustable rear lever shocks. They may still have them.
Wade Keene

Wade-
I don't have any comprehensive information on how specific cars were set up for particular races (though I'd drool at the opportunity to get such valuable intelligence), but if you're not out to do a faithful reproduction of a specific car, any well-functioning combination of period-correct stuff would seem to be acceptable for your purposes.

Michael-
The only reasonable justification that the factory works team would have had for going to stiffer springs would be to retain the car's handling at higher speeds than would be possible with the standard springs. However, the information below shows that sometimes they chose stiffer, sometime they chose softer-

The working loads of the standard rear leaf springs were as follows:

Early Roadster: 400 lbs
Late Roadster: 450lbs
GT: 510lbs

The working loads of the rear leaf springs offered by the Special Tuning Department were as follows:

Part# C-AHH 8343: 375lbs
Part# AHH 7346: 542lbs
Part# C-AHT 20: 542lbs

The working loads of the front coil springs offered by the Special Tuning Department were as follows:

Part# AHH 6451: 1030lbs
Part# C-AHT 21: 1193lbs
Steve S.

This thread was discussed between 07/04/2003 and 10/04/2003

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