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MG MGB Technical - Knocking rear shocks

I'm on my third set of rear shock absorbers now - the last two have been Spax, and whatever I do they all seem to fail very quickly and I only get a couple of weeks of driving before the knocking starts.

I've read about this being a common problem, but what have people done to overcome it? Is there a better brand, or is the only option really to convert back to lever arm dampers? For the record, the shocks are being fitted properly, and being pumped through their travel to expel air before being put onto the car.

Thanks in advance
Martin
Martin Port

I've had the same problem with Spaxes, completely useless really and are too hard damped as well even in the softest setting. I converted back to uprated lever arms and had no more problems plus the car is now well damped and sits well on the road.
Iain MacKintosh

Martin,

Firstly you don’t mention whether you are using multi-leaf springs or single parabolic springs?

The problem with the tube damper conversion is that the damper is inclined at about 30deg and up to 45deg during serious 'bump' conditions.

This means that there is a lot of side load placed on the shaft/seal for which it was not designed, leading to early failure.

The damper 'should' be mounted vertically (in the direction of movement for the rear axle) this will almost eliminate the load on the damper shaft making them last a 'proper' service life and provide better damping characteristics.

Mounted correctly, the damper wont be as 'hard' as when they operate at very severe angles, as the side load tends to bind the shaft on the seal and the internal piston.

I can send you a CAD drawing and photos of a new top bracket that will cure this problem, if you like? A local metal fabricators or engineering firm, should be able to make a pair for about £30.

The alternative is to go back to the lever arm dampers, these are fine when used with standard multi-leaf springs as the interleaf friction provides inherent damping.
MG Mike

ive been down that road and had three sets of spax on my roadster.have you tried the up rated lever arm with about 25% more stiffness,im very happy with them and very cheap thanks daren http://www.mgbhive.co.uk/
Welcome to MGB Hive .
daren

25% ? Is that with a rubber bumper car or chrome?
kids1

you can get the uprated shockers for both,gives you the mg origanal feel but slightly stiffer http://www.mgbhive.co.uk/
Welcome to MGB Hive
daren

MG Mike,I would love a set of drawings and pictures www.riclloyd@juno.com THANKS RIC
Ric Lloyd

Ric, Tried sending to www.riclloyd@juno.com no luck, my service provider says that is not a valid email address, do you have an alternative?

Mike.
MG Mike

Damn,Damn,Damn-Mike if I could have your E-mail I'll e-mail you and you can reply thanx Ric
Ric Lloyd

Try taking the "www." out of the address.
Steve Simmons

Seems to me that badly implemented tube shocks are not as good as the original levers, so why waste any more time on them - just put back the Armstrongs, uprated if appropriate for your planned usage.
Bill Spohn

Yrs ago, if you sent in shocks as cores and they were not rebuildable, you didn't get the core and they were not returned to you. The only reason I could see that they are not rebuildable is if they are cracked. Can't the hole for the shaft be sleeved? I'd love a set of lever shocks for the rear but not for full $.
kids1

Mike!

I would be very happy if you could send the top bracket drawing to me!
Per Sjöberg

Hi Per, as the .pdf drawings and photos are quite large I've up-loaded them to the following web site;-

.pdf drawings are at;-

http://digitalvault.bt.com/invite/login?c=313036363038&i=4b50-11130e9c3be-gemini01&t=6bfec9dab63a3712&r=mg&lang=en

and photos at;-

http://digitalvault.bt.com/invite/login?c=313036363038&i=4b52-11130e9c3be-gemini01&t=f88a73e93dc43d27&r=mg&lang=en

I hope that works? if not let me know and I'll send them one at a time!

Regards,

Mike.
MG Mike

Mike who's better then you? Very nice indeed! I got the pictures to print but the drawings are giving me a problem, not to worry I will make it work.Once again thanks.
Ric
Ric Lloyd

Perfect!!!

Per
Per Sjöberg

This thread was discussed between 27/02/2007 and 10/03/2007

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