MG-Cars.net

Welcome to our resource for MG 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 Midget and Sprite Technical - Rear armstrong adjustables

Does anyone have (or had) adjustable Armstrong levers on the rear of their midget/Sprite?
Rob
MG Moneypit

Yes, I did have.
Dave O'Neill 2

Hi Dave, did you need to use a spacer to allow the adjusting knob to clear the inner rear wing or did the very bottom of the inner rear wing next to the rear bulkhead need relieving for the same reason?
Rob
MG Moneypit

No, they fitted straight on with no mods.
Dave O'Neill 2

The image shows the nearside, but the mounting bolts are only loose. As you can see the adjusting knob is touching the inner wing. If I were to tighten the mounting bolts it would jam up to the inner wing and be impossible to adjust.
If the inner wing did not project so far down it might be OK. I'm sure I could trim it if necessary but I just wondered if it would be OK to do this.
I've searched Google to try to find pictures of these fitted but I only seem to find the ones that are modified standard armstrongs with two external pipes with balance valve between
Rob



MG Moneypit

The photo helps.

The adjustment knob seems to be in the wrong place.

If you look at mine, the knob is away from the mounting face, whereas yours is adjacent.


Dave O'Neill 2

I was just looking at the pair on ebay at the moment and came to the same conclusion.
So the ones I have are not for a Midget.
I wonder what the different positions do and is it a case of swapping the valves between the 2 cylinders. Surely, Armstrong would not cast different bodies for such a low production number?
Rob
MG Moneypit

Rob
In Daniel Stapleton’s book he has a pic of an adjustable damper with the comment ‘this one is for a Semi- elliptic spring car’ - it has the offset adjuster.

Did the Frogs have a different type ?

Worth an e mail to Daniel to see if he can cast some light onto the subject.

I think I have his details somewhere if you haven’t and want me to mail him.

R.
richard b

Rob,

It would seem Armstrong did make a special body for the adjustables as they have provision for 2 valve assemblies whereas the normal ones only have provision for a single valve assembly. Looking at the image I was wondering if it's just a simple matter of swapping the fixed and adjustable valving over so they're arranged as in Dave's photo.
David Billington

Rob, I would be cautious about trimming the "inner wing" as you refer to it. It is the triangular support to the rear of the car, holding the rear boot floor and in turn the whole of the rear deck at the right angle to the rear bulkhead. Definitely a structural piece!
You could maybe cut a carefully positioned hole in it, just enough to give the clearance needed for the edge of the adjuster.
GuyW

I’ve e mailed Daniel.

R.
richard b

Thank you Richard.
David B. yes I knew that already but I speculated that Armstrong only made one casting with 2 valve assemblies so maybe it is a case of swapping over.
Guy, yes it's not something I would do unless desperate.
Another difference I have noticed is the arm on the standard Midget shock is angled towards the mounting flange whereas the ones I have are angled away.
So if it is a case that I need to swap valves and arms then I think it would be wiser to sell these and get a pair that will fit a Midget.
When I got them they were attached to adaptor brackets consisting of a 1cm thick metal plate with countersunk screws to attach the shock to the plate and 2 holes to attach the assembly to the inner wing.
He said he thought they were Midget shocks and the adaptor was used to fit them to a Ford Anglia 105E. So maybe the whole assembly is for a 105E?
Rob


MG Moneypit

Give Derek at Stevson Motors a ring - 0121 472 1702

He should be able to tell you if the valves can be swapped over.
Dave O'Neill 2

Rob

The MGA guru site (MGAguru.com) shows adjustable shockabsorbers fitted to an 'A' with the adjustment knob in the same place as yours. They clear the chassis rail. It also shows the shockabsorbers with the adjustment knob away from the mounting face. It seems to confirm Armstrong did manufacture different types despite the limited production runs
Bob Beaumont

I found this on flickr https://www.flickr.com/photos/78408455@N04/18579237590/in/photostream/ for an MGB rear adjustable LA damper rebuild, if you scroll through the images it shows both valves in the same shot and the threads and ends that screw in look the same apart from some differences due to the adjustable bits. It would make sense to me to make the chambers that take the valves the same to give flexibility in placement. I assume that both valve chambers both connect between each cylinder to allow an alternate and possibly easier way for the fluid to travel to alter the rate.
David Billington

I distinctly remember reading in one of the MG books that they made a run of 20,000 pairs, which suggests a bigger difference than just the way they were assembled, i.e. different bodies.
David Smith

This is Daniel’s reply to my query :-

From memory the difference is only in the arm length between Semi and quarter elliptic spring units - the bodies being the same.

R.
richard b

Thanks all, especially Richard B for emailing Daniel for me. I have his book somewhere, infact I've got Iss1,3 and 4 so will look to see what else he says.
Also Dave O for the number for Derek at Stevson Motors. I shall ring him in the morning.
In my meanderings around t'internet I came across this about refurbing the seals to cure leaks
https://www.morrisminorowners.co.uk/viewtopic.php?f=32&t=8339
It is a fairly low-tech method of replacing both seals although I think he went overboard on the milling out for the rear seal. Why not just replace the circular seal and fit an ally welch plug? Read it, you will see what I mean.
Rob
MG Moneypit

Here's a good image from the flickr page showing the damper parts. Looks like the BB resizes the image somewhat as once viewed that is a smaller file size and lower resolution than what was uploaded.


David Billington

David B, thanks for the link to flickr. The BB seems to resize to 640x480 but I have downloaded the full size images. The valves do look the same thread so I think they can be swapped over. I'll ring Stevson Motors and make an enquiry before doing anything.
If I'm able to swap the valves I might as well do a full rebuild and replace all the perishable bits and the oil at the same time.
I'm lurking eBay at the moment for a set of standard rear shocks just for the arms so I can make it 100% Midget.
I'm surprised that the only reference I can find that addresses the question "What stops the arm from working it's way out?" is the tightness of the splines in the cam!!!!
Attached is a closeup of the valves.
Rob



MG Moneypit

Rob,

Likewise I saved the high res images from flickr for future reference if needed. From looking at the parts I reckon that the fixed valving gives a high damping rate and the adjustable acts as a bypass to lower the effective rate as the components seem to form a simple needle valve.

I also noted that the person in the album has or had access to the fabled Churchill 18G 191A and B step tools for setting CWP etc, any idea how to contact the person.
David Billington

OK, so phoned Stevson and no answer. I phoned twice but despite 2 mins wait there was no answer. Found Stevsons website and links to anything lever arm related don't work, they just end in error.
I found Stevson Motors on eBay and he does advertise lever arms so maybe not having links on his website is a requirement of having an eBay shop?
All the current lever arm offering for Stevson are high value items. Your lucky you don't own a Rolls Royce! £1200 each reconditioned.
The link I gave to the morrisminorowners website won't work if you click on it, but if you cut and paste the text it will work.
I'll keep trying Stevson.
Rob
MG Moneypit

Rob,

MM site link works fine for me when I click on it.
David Billington

David, yes I just tried it again and it works. When it didn't work it redirected to Google search page. I tried it several times with the same result but now it works OK.
Must have been a Googleism or Googleitis or something?
Rob
MG Moneypit

I finally got through to Derek at Stevson Motors and now I'm completely confused. According to Derek "Armstrong never EVER made an adjustable with the adjuster on that side" and "he's been doing it for 60 years".
I had a look at mine and there is a 4 digit number on the side (7398) which Derek identified as Ford Anglia 105E. He reckons someone has been fiddling with it, which I doubt very much as it looks to me like it's never been touched at all. He suggested, however, that if I send it to him he will have a look at it.
He was also adamant that the adjusters could not be swapped over.
So most confused.
Rob
MG Moneypit

Rob
You would probably be better off speaking to Peter Calver at Worldwide in Minnesota about shocks. He recons Armstrong adjustable as well as upgrades them. Poor review from a Club member about Stevsons.
The spindle is held in place by a crimped bit of metal. They seem quite fragile when consideration is given to the jarring and juddering they probably receive on our modern potholed roads.
Alan
Alan Anstead

I hope I've got it right as it took me three attempts to find the name, I think Alan means Peter Caldwell of World Wide Auto Parts, Madison, Minnesota -
http://www.nosimport.com/index.php?route=information/contact
Nigel Atkins

that's the one Nigel.
Alan
Alan Anstead

I knew the name wasn't quite right but being close didn't help me, of course as soon as I saw it - I instantly forgot again! (I couldn't even remember the correct name of the company so just did a quick Archives search here).

Nigel Atkins

Calver is the mini engine specialst.
GuyW

I emailed Peter Caldwell and almost instantly got the following reply.

"Robert, they ARE interchangeable. We have done it often. You may have other issues such as arm clocking and bend and length. Be sure your bump stops will prevent the arm (pistons) from bottoming out.

Peter"

Excellent service, freely given. It's a pity shipping is so expensive.

So now we know definitively.

"arm clocking" must refer to the sweep of the arm.

I'm just waiting for eBay to produce a pair of standard shocks and I'll have a go at getting the arms out before committing to modifying the adjustable ones.

Also, Alan A mentioned that they are fixed with a crimped bit of metal but I am wondering if this only applies to single arm front dampers where the security of the arm is very important and subject to lots of stresses.

Rob





MG Moneypit

Hi
Keith Calvers is the mini man. I have read many of his excellent articles in Mini magazines.

Rob. It was the front that had the crimped metal. I found it when I disassembled a poor one from Peter Caldwell. He did change it, and another, for me after I sent him a video of the faults.
Alan Anstead

This thread was discussed between 08/04/2020 and 10/04/2020

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.