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MG Midget and Sprite Technical - Front lever arm dampers

Does anyone know what results in a front damper being unsuitable for reconditioning. Is there a bush or bearing that is replaceable to remove any play in the arm.
S Macfarlane

If you have had a unit rejected, for one, a sheared off pinch set screw in the end of the lever arm?

But there's probably more.
GuyW

There is probably not a lot. Times move on and matters have improved. Valves can be replaced, bodies bushed but of course a good recon will not come cheap.
If your shock has no leaks then Malcolm Le Chevalier supplies a refresh kit: oil, gasket, & new machine screws. Fresh clean oil can make a difference.
Ahead-4-Healey claim to properly recondition shock absorbers: might be worth a chat for them t o explain what exactly they do.
Peter Caldwell in USA supplies recon’ shocks but then you have to add postage, duties, and forego exchange as the postage makes return of the worn shocks uneconomical. It can be problematical if a problem arises because of the distance involved. Unfortunately sometimes even his leak.
Alan Anstead

V and C engineering in Bala, N. Wales will recondition them. They'll give you an online quote.
Bill B

I have examined a number of dampers where the oil level has been allowed to drop too low which results in the upper (bump) cylinder suffering wear to the bore from the cast iron/steel piston ring.
The only resolution is to bore and sleeve however I do not believe that V&C undertake such repairs unlike Peter Caldwell in the USA who has advised me that around 10% of the dampers sent to him require such rework however he waits until he has a suitable quantity to undertake a batch approach for their rework probably due to machine set up time/cost.
Prevention being better than cure so check oil levels every 3 months.
The shaft seals were intended to leak for lubrication purposes so fluid loss is to be expected.
S G KEIL

Did you get yours done at V&C Bill?
anamnesis

anamnesis
VCSA at Sanderstead, South Croydon restore shocks. I have heard of them but not used them. Nearer to you.
Alan Anstead

Anamm
No, just got a quote. Still thinking about it!
Bill B

Thanks Alan. I'll email them and ask them what exactly they do when restoring/renovating shocks.

I take it yours are still not too bad then Bill. My fronts are beginning to show signs they need attention. May just need a change of oil; no leaks. But there's a bit of a flat spot.

As I'm not doing great mileages, I can probably keep them going. But if renovation is good and cheap enough, it's probably worth fixing them.

Or I fix my FL's, -- finally, by rebushing them.


anamnesis

Anam,

If by flat spot you mean a bit of undamped movement that is likely due to wear in the body and/or shaft and would require a decent rebuild, a bit more than new oil and paint.
David Billington

Yep I'm sure you're right Bill, and mine are on the way out too, -- unsurprisingly given how long I've had them.
anamnesis

So is it correct to think that the only fully remanufactured shocks are from Peter Caldwell? However they come at a significant cost.
Has anyone tried new shockers from the usual suspects, are they the usual cheap tat from the far east or are they reasonable?
Jeremy MkIII

I noticed that VCSA don't mention machining if required so that seems to leave the people in North Wales mentioned earlier who do https://www.vandcengineering.co.uk/ .
David Billington

Thanks David,

so the V&C people do the necessary machining if needed? I think Bernie was having his done there, wonder how he got on?
May be worth giving them a ring to see exactly what they do.
Jeremy MkIII

As I said in above comment you would need to check if V&C undertake an refurbishment of cylinder bores as I thought not.
S G KEIL

I have MGB front shocks on sliding plates from Mamba Motorsport. I had bought them from eBay and took them to V&C (one had been leaking).
They refurbished them and altered the droop so that the shocks would touch the lower bump stops (you have to fit an extra stop to accommodate the second arm). This was necessary because on the B the shocks are mounted flat, but on the Spridget they are tilted upwards so they would not normally contact the stops. They also reduced the resistance to match the lighter car so that the ride would not be too hard.
The shocks are very good and the car feels more “planted” on the road.
I’ve also had another set done by V&C for my project midget.

Bernie.
b higginson

Thanks for the feedback on V&C Bernie, it's heartening there is still somewhere doing a good job in refurbishing our old dampers.
just need to get mine off now.
Jeremy MkIII

I’ve sent a spare pair to Peter May. I’ll see what response comes back.
S Macfarlane

Another issue that I have also encountered is where there is play between the shaft splines and the rocker arms.
Whilst this can be be felt when just cycling the arm movement it can be better checked by removing the cover plate and observing lag between the arm movement and that of the rocker arms.
I have achieved some resolution by placing a close fitting steel plate between the pair of arms once removed from the damper and peening around the splined holes to achieve some improvement but as parts are not heat treated by hardening and tempering such wear is only to be expected following significant usage.
I have a couple of donated dampers where previous 'refurbishment' of this feature was addressed by heavy use of a cold chisel to achieve zero effect !
The only other option may be to apply some weld where tig would be preferred approach however this would be a final action with no further option.
I have also considered welding a spacer between the arms to replace the original crimped sleeve with a cross drilled hole and shear pin however to confirm effectiveness would require some load testing to optimise size of pin vs weakening of shaft.
I have not seen any comments on the subject of such wear of the splined features but have not checked with Peter Caldwell if he addresses this detail.
S G KEIL

Thought I would add to this thread rather than start another. I have got a pair of front shocks out from under the bench and thought I would service them and put them on the car but I have noticed one has a bigger gap between the body and the arm , you can see some splines whereas the other is close up against the body, is that how it should be ? . The castellated nut still has its split pin in . Is it just a case of tightening that nut or pulling the arm off ( how feasible is that ? ) cleaning the splines and putting it further on . Otherwise they seem pretty good in terms of movement with no leaks but fancy changing the oil at least .
Mike Fairclough

You would normally expect to see a gap of around 1/8” or so.
It’s not so much how far the arm has been pushed onto the shaft, more how far the shaft has been pushed into body.
When dampers are rebuilt, the shaft has to be removed in order to extract the rocker and pistons.
It’s not normally a problem as long as the arm aligns with the top trunnion link, without having to force the kingpin either towards or away from vertical. Although it’s not quite vertical.
Dave O'Neill 2

Thanks Dave certainly looks more than 1/8 inch see attached photo


Mike Fairclough

How much difference does it make to the castor angle?

What is the correct angle anyway? Must be in the book, but I don't have one to hand. Seem to remember a figure of 3 degrees positive castor.

Suppose it's a degree or so off, how much effect would there be to handling?

But definitely forcing the kingpin over to engage the top trunion with the damper arm, causes a lot more (eneven) wear on the lower threaded fulcrum pin and wishbone bush. I know that from experience, as many of us have probably found over the years.

anamnesis

Castor is controlled by the 3 degree bend in the frame rails. Any variation in the lever arm at the top would increase or decrease that, but also stress the bushes and the fulcrum pin.
GuyW

Yep I agree Guy.

I was wondering how much a misaligned lever arm would affect castor angle.

And if it caused a degree of error, would be noticeable?

Must be easy to calculate I guess.

If say 1/8th inch error. What angle degree shift is there, at the top of the circle from the centre of the hub to the centre of the top trunnion?

anamnesis

This thread was discussed between 14/01/2025 and 25/02/2025

MG Midget and Sprite Technical index

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