The Aftermath Of Scotland

[AlanBartlett]

What a fun weekend I had. The next day, engine is out and clutch is apart. Now for those of you that werent at scotland, I had developed a clutch slippage at higher gears say in 3rd or 4th gear. The engine revs high and higher and is going no where. Suggested at the rally was maybe oil, so poured down the holes fullers earth and talc baby powder to soak it up but having taken it apart, it reaveals no oil inside and the clutch aspestos bit is still intact.

[george garside]

[quote="AlanBartlett"]What a fun weekend I had. The next day, engine is out and clutch is apart. Now for those of you that werent at scotland, I had developed a clutch slippage at higher gears say in 3rd or 4th gear. The engine revs high and higher and is going no where. Suggested at the rally was maybe oil, so poured down the holes fullers earth and talc baby powder to soak it up but having taken it apart, it reaveals no oil inside and the clutch aspestos bit is still intact.[/quote]

Alan
just a couple of thoughts on the matter.
1. is the clutch lining (the asbestos bit) worn thin (but intact) I dont know what the minimum thickness is but somebody somewhere will know - if you have another clutch campare thie thickness of the linings. my reasoning is that if the lining is worn very thin it will effectively reduce the pressure of the clutch springs which will reduce the clamping action of the clutch.

2. on a similar train of thought are the clutch springs knackered i.e. not as strong as they used to be. if you have springs from two clutches a simple way of picking out the strongest ones is to put them in vice 2 at a time end to end. close the vise & the weekest spring will close first - put it in the knackered pile and carry on the process with all other springs untill you find a set that when sqeezed in the vice contract by more or less the same amount.

every mechanical problem has a logical cause - the problem is finding it!

[Tony Fearn]

Hello Alan.

If you find that George's idea about weak clutch springs is perhaps the cause, let me know, I have a tin full of them - all used of course, but I no doubt will be able to supply reasonable ones - (gratis, but only to you).

I also have (in the loft) a new pair of clutch discs, so if you want me to measure their thickness let me know. If your discs are worn, then you'll be able to see a step in them where the steel plates connect.

Hope you and mum and Chris got home without any bother.

Tony.

[Keith Andrews]

Hope you and mum and Chris got home without any bother.

The more bother the better....
Just how one looks at it...
At the time the heavens are caving in,
in retrospect....another great story to tell your grandchildren when sitting on your knee...
Better still when the heavens are caving in, think...great story, cool Im not going to be a boring old grandfather...

[Tony Fearn]

Hi Keith,

I met your mates Alan Stanley and Barbara at Crieff, and perhaps on their perigrinations within the U.K. they may come to stay with us for a day or two.

This was truly an international Rally, but I reckon you should be saving the dollars to come over here in 2010, the 100th anniversary of the first Jowett to be sold to the general public, but I can't promise you the use of a Camero!

Best wishes,

Tony.

[AlanBartlett]

Hello,

The springs both start to compress at the same amount, so would this mean that they are all ok? What would you recommend as the next move?

[Tony Fearn]

I've spoken to Alan, and suggested that he should telephone a couple of well-respected Jowetteers who are used to the pre-wars.

However, he still seems to be having the same problem with the clutch slipping.

Now as far as I am aware:-

1. There's no oil within the flywheel or on the clutch plate, the Fuller's earth and the talc introduced at Crieff are still powdery on dismantling the flywheel/clutch.

2. The two parts of the friction plate are not worn, and the spring "star" plate in between them is present.

3. The clutch springs are all ok with an equal pressure for each of them.

So. I've suggested:

1. That he checks for any burring on the gearbox splined shaft or inside the clutch plate splines, and remedies any such problem with a fine file.

2. That he makes sure that the actual clutch plate slides forwards and backwards on the gearbox shaft easily.

3. That the bearing on the rear end of the crankshaft that fits inside the front of the clutch plate assembly is positioned correctly and allows the plate to move forwards and backwards without friction.

4. Check the side play in the clutch pedal cross tube, on to which the thrust race arms bear.

5. That he slackens all the bolts on the various bits that disengage the clutch when the pedal is depressed.

6. That he slackens the lock nuts on the three toggle arm levers on the rear face of the flywheel and screws out the adjusting screws so that the springs are able to exert maximum pressure on the clutch plate sandwich, subsequently screwing them in until they feel to be just touching the backplate.

Now then. If the sandwich of rear face, clutch plate and front plate are free to exert all possible pressure between them, then if everything else is set-up properly there shouldn't be any clutch slip at all.

Here's the rub.

In what order should Alan sort the rest of the mechanical items out so that when he lets the clutch out after changing gear there is no suggestion of clutch-slip.

As a post-script, years ago I was very depressed when I couldn't start 'Mary Ellen'.

I rang a good friend who offered to help. His immortal words (in my mind) were:- "Don't worry Tony, It's a machine. It can be mended".

Can anyone help with suggestions please.

Thanks Tony.

[PAUL BEAUMONT]

I reckon what you are saying makes a lot of sense Tony! I suspect , Alan, that you may have been too careful in tightening everything up a bit too much.. You need to ensure that everything can move and has some free movement. this includes the toggle levers and the pegs that force the clamp plate to move, as well as the pedal cross shaft. The issue is really simple, if the springs are ok and working (which it sounds like they are) something is stopping them doing their job. So off you go Sherlock find it!

Alan, it may sound a bit odd, but you need to get to a situation where changing or engaging gear is difficult or noisy and then re-adjust everything.
Didn't you have problems with the clutch in the early days? what did you change then? was something wrong?

[AlanBartlett]

Paradox evaded, get a mop.
After hoisting the engine out a second time in 2 weeks, and proceeding on with the gearbox also coming out.

The problem was infact the star spring in the middle of the asbestos lining, on my clutch the gap had closed compared to a new one which I had ordered as a last resort, so swapped them over and everything was good to go.

Carefully tightening the cheese head screws around the the fly wheel, then snap crackle and clunk. What is that? The front clutch toggle lever plate, CRACKED, After getting a little angered and raged with getting the gearbox out, I am now past the anger stage and feel nothing but pity for the old girl, maybe she just doesnt want to be fixed at this point in time, if she does shes making it more and more difficult by the job. Its like plumbing you plug one hole and another one forms.

I have a feeling this is going to be long summer, Never the less I intend to do what ever it takes to get this car back on its road wheels.

[Forumadmin]

We have all been there. Patience and resolution are required in plane loads.

Not sure of your mechanical skills; but even experienced engineers learn that Jowetts are a bit different. And old ones even more so. You need to learn the breaking point of aged metal which might be less that when it was new. You need to learn to tighten and loosen things evenly and progressively and with that touch and feel that only years of practice or a good teacher instill.

Often it is not you that caused the stress fracture; but something in its past life (or just age). You just were the last straw.

A good understanding of metallurgy , heat treatment and torque settings may help reduce such occurences.

[PAUL BEAUMONT]

Alan do you have a spare? I am sure people closer to you than me do have, butr if you are stuck I almost certainly do.

[AlanBartlett]

Thanks for the offer Paul, luckily found a spare. And I can now say its back together, but not set up yet.... watch this space

[AlanBartlett]

Right then, Ive fitted it all back in place and the engine is still running silently or virtually silent. But, now heres the thing, the clutch is now failing to disengage to change into any gears. Now Ive been thinking is it

A, to adjust the rods either longer or shorter, I'm thinking shorter, as it is a new clutch so wouldnt it be shortening back to factory length kind of thoughts, I'm confused as to which.

Or

B Ive incorrectly adjusted the push pull lever on the side of the gear box.

I know Ive adjusted all the toggle levers with my 2p method so they should be ok, but if the above is in correct then this would also be incorrect, could someone point me in the direction of which way the rods go to adjust either way as I'm still at little confused.

[Keith Andrews]

I'm confused as to which.

yes we all get ourselves 'confused by science' every now and then
The best sol'n when this happens is make a cup of coffee, get a pen and paper, forget what is in your head, then draw a simplified picture of what levers what way

[PAUL BEAUMONT]

Alan, this is now good news because it means that the clutch is engaging properly. What you now need to do is adjust it so that the free play in the system is just about eliminated. I cannot recall exactly the set up on your car, but if you get a mate to push the pedal while you watch what happens, and then adjust it so that it happens earlier. On the Bradford this sometimes means rotating the clamp on the cross shaft through the gear box rather than adjusting the rods, but if you stick to first principles it will show you what you need to do.