Torsion bar renovation.

[Keith Clements]

I have come across probably the only thing I have never renovated or fixed on my Jup so am after some advice before I attack it.
I am attempting to replace the dampening ring (Item 3112 Part Number 52908 on page 45 of the parts book). I obtained new ones which are from a VW beetle from Jim Miller.

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This is housed within Item 3423/3409 on page 50 .
I have removed the torsion bar using my home made puller. That was surprisingly easy. Mind you the bars had been put in some 30 years ago with copper ease.

However, the ring seems to be held in with a wired huge hex nut about 1 7/8 in (47mm)  across flats. I do not have a drawing of the assembly so cannot figure out how it works. My guess is the nut screws onto boss of the torsion bar adjuster lever boss. The nut/ washer then holds in the rubber damper cylinder.

There seems to be no easy movement on the adjuster so I suspect the rubber is hard inside the dampening ring. The adjuster does adjust under load though.

The question is how do you remove the ring? Will I have to burn it out?  Currently the floor is in the car and I suspect this will have to come out to get sufficient purchase on the nut. On the other side the petrol filter is very close to the adjuster so burning may be risky.

Once the nut and washer are off maybe I can push out the adjuster lever, but I doubt it!

The parts book is vague and possibly incorrect. Where does Item 52911 (the washer ) go? Where does Item 3114 (the 7/16 nut) go?

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[Keith Clements]

Thanks to James, Scott, Neil and Michael responses which motivated me.
I took the seat and floor out . Then I designed a puller. A 36.25mm washer was turned to grip the tube. A gearbox output boss was used to create a bridge.

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Amazingly it worked. The rubber was distorted as James predicted.

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[Keith Clements]

Remove the nut, work the arm out using the lever arm. A few have come out with a hammer and wood block, pounding on the nut so as not to damage anything. A few come out working the lever arm up and down while pulling. Two took a torch and were rather difficult, with one leaving the rubber still inside the adjuster arm.

All of them were done with the floor out.

Nut 3114 is the locknut on the adjuster bolt.

Washer 52911 fits between the rubber bush and the huge nut.

Would have responded on JT, but locked out again. I forget passwords, sure, but this time I know my password. Used the "forgot", but still nothing in my email after an hour. Not the first time I have no response from "Forgot" and the last time it simply reverted to using my password that it would not accept the day before. Tried a couple of variations just in case, including older passwords.

Cheers
Scott

m down at Fielding rebuilding an engine for one of our members here after racing at Manfield on the weekend. Unfortunately I don't have the Jup parts book so can't identify your numbers, but, taking apart shouldn't be too difficult.
The red stuff makes 2 and the original rubber version is in fact only a packer or spacer between the adjuster arm and the tube housing welded to the chassis. The nut and washer are on a fine thread on the rear end of the adjuster arn and the nut wired as a locking device. While the arm can move it is not loose as it revolves inside the outer tube and sleeve. After 60 odd years the rubber is hard but it's not bonded to anything and the adjusting lever arm minus nut should be able to be drawn forward with a suitable puller thro the middle of the octogan for the torsion bar. Perhaps a long rod threaded both ends a few inches and a couple of steel thick washers. The only time the arm moves is when adjusting the car height so I wonder why you want to replace the sleeves, they don't appear to be worn or damaged. Unless a chassis is being stripped I would leave well alone . It's one part of the Jup that apart from excess heat in that area is there for the life of the car!
There is very little info in the parts book or the manual for the above reason, and if required it's what you see is it. The torsion bar is held in place by a small plate and 7/16 BSF bolt in bar and a smaller bolt into the mount on the chassis . That's probably your bolt. Regards Neil I'm home early next week.

Hi Keith,

I know Scott has removed and replaced a few I have only removed the ones on the Farina and they came out suprisingly easy. The replacement fit is excellent. One bush makes two and must be cut to fit. Place the new bush inside the housing and then force the adjuster arm into it. I 'd cut just them a hair long as it will still compress a little when tightening. I don't know that there will be any noticable handling improvement since they are just isolation bushes but should always be replaced during a rebuild since they are always worn out usually just on one side from the pressure of the torsion bar.

Cheers ,

James

Thanks Keith,

On my Jupiter. if my memory is correct, back to 1966, the large hexagon nut was secured with copper wire and I assumed that it was original, purely because it was a professional looking twist job – not an amateur’s mutilated effort. I have not replaced these bushings on my car – yet.

My car is over my pit at present and I will get under for a good, well-lit look. My intuition is that the original is still in there and, if there was a need to replace the ring, I would take the following action:

1. Remove the nut and, I assume, the plain washer, which again I assume, would be inboard of the nut.

2. Use a drill 1/32” smaller diameter than the inner and outer diameter of the bushing’s position. I would assume that the bushing material would be quite crumbly at its age. Also, my understanding would be that the larger diameter of the shown red bushing’s section would face the rear of the car. If this is so, then two drill sizes would be required for a two-stage removal process. Or, is the main shank of the VW bushing (smaller OD) the part that is used?

3. Drill a series of longitudinal holes, close together until the drill bit just contacts the forward end of the housing.

4. With a sharp instrument, prise out the remainder of the old bushing and clean up the interior of the housing in readiness for inserting the new bushing.

Your question is very valid, it is of great sadness to me that service manuals were written for those who had attended service training sessions, and is, in my terminology, delightfully vague – in certain vital areas. Also there is the comment, ‘Replacement is the same procedure as that for the Javelin’. On referring to that section, it is just as vague!

Mu assumption, and it is just that, is that the bushing should protrude beyond the housing by approximately 3 – 5 mm, so that as the nut compresses it, the damper bushing swells inside the housing as the nut is tightened. Just how tight, I do not know, but I am fairly certain that there should be a specification because of the securing wire feature.

I also assume that the large nut has a fine thread, probably unique!

Will get back to you after getting out of my pit, maybe this afternoon or tomorrow some time.

I hope someone better informed than I am can shed some light on the mystery of the flour-less damper!

All the best,

Mike A.

[Keith Clements]

I cut off 3mm from the face of the VW part in the lathe and cut off to length. It fitted well. Cleaned and painted the adjuster housing.

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