Marina suspension adjustment

[jammmorris]

Hi. Just wondering if anyone knows how I can adjust my ride height.
I have a 66 convertible with marina front and rear suspension. I only purchased in Feb and trying to get it sorted.
Apologies for not knowing the term but the part that would hit against the bump stop is about 15mm from the bump stop on the drivers side and about double that on the passenger side. I'd like to even them up.
Would topping up the oil in the shocks help? If so please can someone explain how to do this as I can't find anything about doing this on marina shocks.
Is there another way the ride height can be adjusted and if so I'd be grateful to know how. The only guides I can find are for full minor suspension.
I've attached photos of my setup.
The ride does feel stiff over uneven surfaces and pot holes. Is that just minors. This is the first I've owned.
I want to replace the trunnion bushes and shock absorber bushes but can't find any marina ones, only minor. Does anyone know if minor ones would fit? Any links to the correct ones would be appreciated.

On a related matter I took my mum and 2 brothers out and noticed that over any dips or speed bumps the exhaust scraped. Is that to be expected in an old leaf spring minor or can something be done to prevent? Exhaust looks secure and not out of the ordinary .

I have replaced the front tie rods with pu ones (just for info).

Thanks as always.
Andy

[philthehill]

You do not have Morris Marina suspension. You have Morris Minor suspension with modifications.
The Morris Minor workshop manual will cover the setting and adjustment of the suspension height.
The top trunnion bushes are Morris Minor. The eye bolt bushes are Morris Minor. Again covered by the BMC wksp manual.
What you do have is a tele-damper modification/conversion on the front which looks to be either a Owen Burton conversion or JLH stage 1 damper kit/conversion.
https://www.jlhmorrisminors.co.uk/suspe ... r-kit.html
When fitting tele dampers the lever arm damper valves should be removed. If that has been done topping up the Morris dampers would be a pointless exercise as regards damping the suspension. With the valves removed the Morris lever arm dampers are reduced to the the function of being the top link only.. I advise that you remove and check the efficiency of the tele-dampers.
I suspect that you also have a tele-damper kit/conversion on the rear.
The only Marina parts featured in the photos above are the Morris Marina disc brake set up for which parts are readily available.

[Steve Phillips]

As Phil says basically you have a Minor suspension setup that’s been modified,

on the front you technically have two shock absorbers/dampers the original units that bolt onto the bulkhead cross member with the arm hanging out through the inner wing, which in turn connects to the suspension upright, and the telescopic units that attach to the lower arm and on to the inner wing by a small bracket, if fitted correctly the damper valve will have been removed from the original "lever arm" unit so only the telescopic unit is doing the damping,
9 out of 10 tines if there not fluid running down the outside of the tele damper then it’s not leaking, and most tele dampers are not re-fillable, just throw away and replace if needed,

Dampers / shock absorbers are what they say they damp the springing and don’t hold the weight of the vehicle so they won’t be affecting the ride height,

to adjust the ride height look under the middle of the car to locate the centre cross member here you will see the end of the torsion bars, these are round steel bars that attach to the lower suspension arms and run back to the cross member where you will find adjustment plates, for small height adjustments use the different holes in the trim plate, if it needs big adjustment (over one inch) you will have to turn the torsion bar one spline,

The top trunnion bushes you require are std minor from what I can see in the photos, so Chris witter or any good minor centre will provide poly bushes to suit.

If the exhaust scrapes first establish is it hitting the road or the underside of the car? Then check its rubber bush mounting, and finally check the overall ride height of the whole car compared with the heights given in the workshop manual,

[jammmorris]

Thanks Phil/Steve. Really useful information. Seems I'm learning things all the time about my car. I was going off what I was told by the previous owner. Hence my confusion. I'll try the adjustments and replacement bushes for a minor.
I was told it's a Marina rear axle/diff. Is there any way you can tell if these photos show its a minor or Marina axle? It definitely has Marina wheels.
Is the rest of my rear suspension minor?
Thanks again.

[philthehill]

The rear axle is a Marina item and it does have the tele-dampers on the rear.
The Marina axle - to make it fit the Minor suspension which is what you have the spring to axle mount is modified to suit the Minor springs.

[jammmorris]

That's good to know thanks Phil.

[jammmorris]

I wonder if anyone can shed any light on this. I measured the distance from floor to top of wheel arch (as viewed from outside the car). It measured 610mm on every wheel except the driver's side which was 620mm. However, this is the one which only has a 15mm gap between the bump stop and reaction pad. The gap the passenger side is double that.
Because the gap is very small between the bump stop and reaction pad I was going to adjust the height of the drivers side using the plate by torsion bar. However, that presumably would make it even higher than the others?
To me it's a worryingly small gap between bump stop and reaction pad at 15mm? Have they lowered it because it's on 13" Marina rims? Is something else wrong?
Can't figure out what is different. The original shock which as Phil says is just acting as a lever arm, is a bit lower than the passenger side. Worn shock? They don't look very old.
Thanks. Hope that doesn't sound too confusing. It's just a very hard ride. I'm aiming to replace all bushes front and rear with PU.
Regards.

[jammmorris]

I wonder if anyone can shed any light on this. I measured the distance from floor to top of wheel arch (as viewed from outside the car). It measured 610mm on every wheel except the driver's side which was 620mm. However, this is the one which only has a 15mm gap between the bump stop and reaction pad. The gap the passenger side is double that.
Because the gap is very small between the bump stop and reaction pad I was going to adjust the height of the drivers side using the plate by torsion bar. However, that presumably would make it even higher than the others?
To me it's a worryingly small gap between bump stop and reaction pad at 15mm? Have they lowered it because it's on 13" Marina rims? Is something else wrong?
The tele-dampers put on by the previous owner were fitted 12 years ago. Done about 4k. Don't look too bad and no sign of fluid leaking .
Thanks. Hope that doesn't sound too confusing. It's just a very hard ride. I'm aiming to replace all bushes front and rear with PU.
Regards.

[svenedin]

Won’t PU bushes make the ride even firmer?

[philthehill]

You should ignore any temptation to measure using the wing as a datum point. The wing is a detachable item and could have been fitted more to suit the looks rather than with any accuracy.
Any measurements should be done using the measurements from the diagram below.
The measurement difference between the inner and out lower fulcrum pins will remain the same irrespective of the size of the wheel.

Suspension height setting.jpg (194.86 KiB) Viewed 1290 times

Replacing the rubber bushes with PU will not make the ride harder. The ride hardness is controlled by the torsion bar and the dampers. What replacing the rubber bushes with PU will do is make the the suspension geometry consistent.

[Steve Phillips]

If your trying to set ride height there's a few basics to start from,

1, are the tyres the same make model size side to side, sounds daft but I've had customers cars with different brand tyres on each side and they are a different diameter,
2, tyre pressures are they identical? Side to side, different pressure different heights,
3, is the car on a flat, smooth level surface? This will affect the way the car sits if its not flat and smooth,

Wheel arches are as Phil says no good for measuring, o:e wings may differ from pattern wings and from glassfibre so you should measure from fixed points as already shown,

Steve

[jammmorris]

Thanks all for replies. I did think that about pu bushes and a firm ride but I've read other forums on mmoc which say modern rubber bushes are dreadful so always fit pu.
I'll measure properly tonight when I'm home from work and use Phil's diagram (still waiting for my workshop manual to arrive). It was the same measurement from floor to centre nut of the arm both sides.
I'll double check tyre info too Steve. Definitely a level concrete floor.
I guess in the short term I'm just a bit concerned how close it is to bump stop and what should the gap be?
Thanks