Torsion Bar Removal Challenge

[Stewart291TMM]

Stewart's 1958 Tourer Restoration

Hi Everyone,
The project continues....
I'm trying to remove the torsion bars on my 1958 M.M. Tourer but it appears the moving parts of the front suspension are not moving, at least barely!
The photo shows the lower suspension arm jacked up to the full height of my little trolley jack, but there is very little movement in the hydraulic damper arm.
The workshop manual says "Raise it until the hydraulic damper arm at the top of the swivel pin is just clear of the rubber rebound pad". I'm some considerable distance away from it and need some advice as to what I can safely do next to get things moving sufficiently to take the tension off the torsion bar for safe removal.

Any helpful suggestions would be much appreciated.

Thanks
Stewart

[svenedin]

Maybe it's the angle of your photo but it looks to me that your damper arm IS just clear of the rebound pad which seems to have lost its rubber?


Stephen


This is the rebound pad, the other rubber thing is the bump stop

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[Stewart291TMM]

Aaaah, that makes a whole lot of sense!

Yes, there is no rubber pad on that metal plate, which I now think is called the "Rebound Check Bracket"? So, actually, the arm does move a few centimetres when jacked up. Is that sufficient to allow the lower arm assembly to be unbolted safely?
Sorry to sound so stupid, this is my first M.M. and first restoration of any kind, in at the deep end!

Thanks
Stewart

[svenedin]

Yes it is sufficient. You don't want to start lifting the car up off the axle stand just sufficient to take the tension off and the weight of the suspension. Your Tourer is considerably earlier than mine so that bracket may be slightly different but the principle is the same.

Stephen

[Stewart291TMM]

Hi Stephen,

Thanks for the advice, I'm going to tackle the torsion bars this evening now I have a little more understanding of what's needed.
Good luck with your master cylinder job, is there a specific reason the bolts for the master cylinder were positioned in that "awkward to get at" way or is there some kind of safety reason?
Seems to make sense to reverse them for future jobs so the torsion bar doesn't block removal of the bolts or am I missing something?

Thanks again.
Stewart

[ManyMinors]

I think the idea of fitting the bolts the way the factory did was that they couldn't fall out if they became loose? I've never known that happen though.
The downside of fitting them the other way round is that the end of the thread can contact the torsion bar under some conditions because the torsion bars do move in use. This can cause an annoying rattle. With the right tool, it isn't that difficult to move the torsion bar in order to remove the bolts.

[svenedin]

The master cylinder bolts have special thin heads and must be the correct (awkward) way round. This is so the torsion bar is not damaged with movement of the suspension. If the bar was damaged it could suddenly fail.

[philthehill]

As regards the master cylinder bolts - I have fitted studs threaded at both ends to suit and have used half nuts at the torsion bar end. The studs are inserted from the opposite side to the torsion bar, the half nuts are then fitted on the outer ends with shallow shake-proof washers under the nuts, a plain washer and S/L nut fitted on the inner end.
The studs clear the torsion bar sufficiently so as not to make contact when the torsion bar is twisted and the studs are easy to remove.

[svenedin]

Phil I like that idea but what stops the stud just trying to thread through the half-nut when you are tightening the nylock at the other end? Maybe I am misunderstanding.

Stephen

[philthehill]

Just a bit of care is all that is required and a bit of suck it and see outlook.
You can fit the nylock nut first and push the stud through the chassis rail from the inside and then tighten the half nut. You could even use two half nuts locked together instead of the nylock nut.

[Bill_qaz]

Maybe it's the angle of your photo but it looks to me that your damper arm IS just clear of the rebound pad which seems to have lost its rubber?


Stephen


This is the rebound pad, the other rubber thing is the bump stop



IMG_1531.jpeg

Hi Stephen can I ask why the lower bolt of the three has so many washers in your picture. I will shortly be replacing these rebound stops on my car so wondered why?

[svenedin]

Good question! I will have to go and look….

The answer is it's just a plain washer and a spring washer. The photo was a small part of a much larger photo zoomed right in and I agree it looks odd.


Stephen

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[Bill_qaz]

Thanks Stephen, new pic is as expected with flat and spring washer on each. Just didn't want any surprises

[philthehill]

There should be a plain washer under the head of bolt and minimum of a spring washer under the nut. The bolts to be inserted from under the wing. As there is the equivalent of a plain washer (the metal plate of the bump stop) there is no requirement to use a additional plain washer under the spring washer.
I am in the process of upgrading the front lower bump stops to reduce the downward movement of the damper arm so as to allow clearance between the tele damper and the top trunnion and have used what appears to be the original factory arrangement that is the bolt, plain washer under the bolt head, spring washer and nut to attach the Minor lower bump stop metal to the inner wing/flitch plate.
The lower bolt can have a plain washer under the spring washer, there is no requirement to have a plain washer under the head of the bolt as the bump stop metal can be used as the plain washer as per the two top inner mounts..
The bolts used are 1/4" x 3/4" UNF with plain nuts.

[svenedin]

Not shown very well in the parts book

AKD3541 Rebound.jpg (70.43 KiB) Viewed 4214 times

[Bill_qaz]

Thanks Phil, sounds like standard assembly,flat washer where no bracket. The new bolt size is useful info, in case the originals put up a fight.

[svenedin]

This is a very zoomed in part of a photo but Phil is spot on as usual. Here is my original rebound stop. You can see there is no plain washer under the nut on the metal bracket.

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[jaekl]

As you see in the photo of an original mount, the plain washers are large to spread the load out.

[Bill_qaz]

Fitted two replacement rebound stops today so now have rubber rather than bare metal. The new ones from ESM did not match the bolt pattern. The bracket had to reshaped by squeezing with large slip joint pliers to bring the lower single bolt hole in line with the hole in the body. New bolts and appropriate washer but put the bolts through from inside to outside as easier to start nuts when working alone Need arms like a gibbon to reach under bonnet and under wing

[svenedin]

Well done. There are so many jobs that are rather difficult when working alone. If it was a professional garage there'd always be somebody to ask to hold something for a minute. Sometimes I do jobs while a non-mechanical friend sits around drinking tea and talking nonsense. I like the company and they can always be the person to just hold that something for a minute! Or they can be like a theatre assistant and pass the required tools. Makes things much easier and more pleasant. The only trouble with this is they eventually get bored and want to go to the pub and of course I do tend to say yes what a good idea!

Stephen