ESM uprated lever arm dampers

[Mr Spigot]

I see ESM sell new Armstrong lever arm shock absorbers that have been uprated by 25%. Has anyone any experience of these?

I have telescopic shock absorbers and while the car handles well, the shock absorbing qualities leave much to be desired as there is a huge jolt every time we hit a pothole or deep manhole and I wondered if these uprated Armstrong units might soften the ride a bit.

[svenedin]

This has been discussed before and cynically we have wondered whether they are ordinary dampers filled with heavier oil! I’d be interested to know if they are different internally. They may well be.

Stephen

[Steve Phillips]

Tele dampers are fitted to millions of vehicles and don't give a jolt over every pot hole or bump.
Perhaps it would be better to look at curing the issue rather than going round it.

I've had minors through the workshop that have had "professional" mods done including dampers that are not fit for purpose. And not correctly fitted.

Why not check what you have and make sure the dampers themselves are not dead. Then check the mounts to make sure they are secure and allowing the dampers to function correctly.

Post a few pics, it will give people a chance to see what you have and possibly look for answers as to what's going on.

Steve

[Mr Spigot]

Thanks for the advice; I always try and ask here as there is usually a wealth of experience which saves wasting time and money on mistakes. They are SPAX gas dampers which were fitted about 6 months ago. I have set them on the softest setting and the brackets all look sound and tight. The springs were replaced about a year ago and poly bushes fitted. There is a slight squeaking from the rear which is probably the bushes and I will be taking them off to grease, but it feels like the dampers are rigid when going over a pothole.
Having read other comments on the rear suspension, I wonder if the bump rubbers are too close to the top and need shortening. There looks to be about 1" of clearance each side and marks where they have been hitting. Maybe taking an inch off the top of each rubber may improve matters.

[philthehill]

The bump stops shown in your photos are very close to the body plate therefore my recommendation as a first step is to take 1" off the top of the bump stop rubber and see if that helps.
There is a post (with photos) on the Modified Minors Facebook page outlining the same problem with the ESM conversion. Their solution was to move the rear lower mounting downwards by 1" as they felt the damper itself was bottoming out.
It is most important that the damper is not given/allowed full travel before the bump stops hit the bump stop plate mounted on the body/chassis rail.
With my lowered Minor I have shortened the rear bump stops to give slightly less than the max travel of the damper piston/internals. Having that restriction ensures that the piston/internals of the damper cannot bottom out and/or be damaged.

[Mr Spigot]

Thanks Phil. I shall look at the Facebook page (there seem to be so many Morris Minor groups now) and try cutting down the bump stops when I have time in a couple of weeks and see how it goes. Lowering the bracket would also seem a sensible move if option 1 does not work, but I note your point about the damper not being allowed full travel.

[philthehill]

Mr Spigot
Here is the link:-
https://www.facebook.com/groups/370998220036705/
It was posted on the 5th May by Steve Budden.

[Mr Spigot]

My final question would be what is the best tool to use to cut the rubber? If I can cut them without taking that off, that would be quicker, but I suppose it depends on how easy they are to cut.

[TravellerROG]

I recently cut an inch off of mine, a junior hacksaw with a nice fresh blade and, with the rear wheel off, it was quite quick and easy.

[Bill_qaz]

Is your car lowered as well as shock conversion?
Just fitted new bumpstop and on picture its much bigger gap than yours, also you have 5 spring leaves mine only has 4.
I'll bet Phil knows

20250415_132832.jpg (978.99 KiB) Viewed 1473 times

[Mr Spigot]

No it has not been lowered and the springs are only 6 months old. The rear hanger does seem to keep the spring close to the chassis though. Perhaps a longer one is needed but they are standard ones as far as as I know. I do wonder why there is such a difference in height for the bump stops when everything apart from the dampers is standard

[philthehill]

I can only answer to what I have fitted which is :-
7 leaf springs with the bottom leaf removed making them 6 leaf springs.
The springs have been reset to lower the car 2"
The springs have retained their 7 leaf traveller loading.
The bump stop height has been reduced by 2"
The clearance now between the top of the bump stop and the bump plate which is attached to the chassis leg is 2" which should be considered as the absolute minimum
The dampers are non adjustable using the original top mount and a new mounting attached to the anti-tramp bar mounting bracket.
The dampers are angled rearwards at the top from the bottom mounting point.
The general arrangement/set up has worked well for over 40 year without any problems.
Getting the mounting points placed correctly for the tele damper is most important and may have to be varied according to the suspension modifications used/fitted.

[Bill_qaz]

Is the curve in the chassis normal or has it been modified for lowering? The spring seems very close for unladen.

Screenshot_20250523-100740_Samsung Internet.jpg (87.98 KiB) Viewed 1286 times

This picture from one of Stephen's posts of new spring fit may help

Screenshot_20250523-101706_Samsung Internet.jpg (129.42 KiB) Viewed 1280 times

[Mervin]

Personally I wouldn't be happy with that "Nyloc" nut Bill. Is the "locking" insert far enough onto the threads to be effective?
I prefer using the original method of a castle nut and split pin.

[Bill_qaz]

Personally I wouldn't be happy with that "Nyloc" nut Bill. I am Is the "locking" insert far enough onto the threads to be effective? yes
I prefer using the original method of a castle nut and split pin.

50 years in vehicle workshops, i know how nyloc nuts work, thanks for your concern

[MikeNash]

Mr Spigot,

Some thoughts: just measured the gap between the rubber bump stop and the chassis on my 1963 Trav and its 1 & 3/4 inches clearance, and I can see the mark where the rubber occasionally hits the chassis, so now and again all the clearance is used. The angle of my rear spring hangers are about the same as yours. My 7 leaf rear springs are at least 30 years old and could be original (the car's been in the family since 1965/6), and so good uns have a long life despite heavy-ish loads and the occasional loaded trailer in tow. (It has had recent new rubbers fitted to the ends of the axle springs.)

A further thought; I've a rubber bump stop to fit (bought from ESM some years ago) and its hardness is 77-80 Shore A. I might as well fit a block of wood! It'll have to be drilled to give some resilience. I think they should be 55-60 Shore A (Our Phil will be along shortly to comment) and I wonder with your small clearance you're using up what clearance you have and coming up a jolt with over hard rubber stops.
Regards from MikeN.

[philthehill]

The shore hardness of the genuine BMC rear axle bump stops fitted to my Minor is 70 shore A.

To reiterate - there should be no less than 2" clearance between the bump stop and the underside of the bump stop plate which is attached to the underside of the rear chassis leg above the bump stop.
If there is less than 2" then there is the possibility of the suspension/dampers not working as efficiently as they should leading to a harsh ride and possible handling issues.