Long Two clutch and flyweel

[BarryCambs]

Coming back from a day out at the Shuttleworth Collection last September, the car developed an alarming and intermittent knocking noise, frustratingly only about 1/2 mile from home. It was still running beautifully, but I decided to get it recovered rather than risk anything damaging the bores and pistons given they have probably only done about 7,000 miles since it was rebored. It sounded very much like the knock the engine had before it was rebuilt and this turned out to be excessive camshaft endfloat. A the time it was recovered, Tony reminded me this is a known thing with these engines. As its a bit warmer, I decided to pluck up courage and ivestigate this weekend.

Removing the timing cover revealed everything to look fine and reassuringly, still clean enough to eat your dinner off. I held the flywheel to stop the crank moving while I check the cam sprocket nut was tight and felt something move! Turns out the Flywheel is loose. I've no idea why it chose that moment to work itself loose. Hopefully we stopped in time and nothing's damaged. I was in the depths of quite serious sleep deprevation due to having young kids when I put the engine together, so I really don't remember how I tightened it. I have found a nice new Impact socket labelled 'Jowett Flywheel', so I imagine I put it on with a compressed air Impact Driver, rather than wedgeing the crank and using a bar. That said, I was also finishing off a house extension at the time and have very little memory of how I did that either! Anyway, hopefully a quick fix and far better than having to strip the engine again.

While the gearbox is off, it is a good time to check the clutch. I noticed that at higher RPM, it loses all free play on the pedal. It's adjusted now to give probably about 2 inch freeplay, but at cruising speed, this disappears. As it transpired parts of the engine were missing when we stripped it down (later found in the boot!) I did check everything off against the parts diagram when I reassembled the clutch, so I don't think it's missing return springs or anything. Is this something anyone else has experienced, or normal?

I notice the Service spec says:

"1930-1939 models have the toggle plate and flywheel balanced as a unit. Make sure their
relative position is marked before removal". The clutch will have been off many times before I ever got to it, so I was pondering having the flywheel/clutch balance checked while it's off in case rough running helped it come loose. I'll speak to or local machine shop, though not sure what they will say about it being taper mounted.

Barry

[Jeremy]

Its difficult to see how the clutch adjustment/free play can disappear with engine rpm - was this when the flywheel was loose? Could that have been the issue? The flywheel moving back, bringing the who clutch assembly with it?

The only other thing I can think of is that the thrust bearing should have a C clip on the end of the clutch fiction plate centre shaft - to stop it sliding off - is this in place? If that was missing I could see how it could move back and up against the levers and need a smart shove to get back on before it pushes against the toggles.

Sorry not much help I fear!

[BarryCambs]

Hi Jeremy

The clutch problem was there for a long time before the flywheel issue. I probably only went a few hundred yards before stoping .

I don't remember a C clip and thats the sort of thing that's going to be easily lost or broken. One of the oddities of the car was there seemingly wasn't a washer left on it, almost as though they had been deliberaty taken off. Even thing like the timing case had the nuts just graunched into it.

I checked everything engine and clutch plate wise against the parts list, but not the gearbox/release bearing side of things. Given the state of everything else, I should have done, but probably figured it was working when I took the engine out, so should be fine! This problem could have been there before the engine rebuild, but it was so terrifying to drive with the botched steering, noticing the freeplay on the clutch pedal, was kind of the least of your worries.

The office is packed up due to building work, but I'll try and find the parts list and see if it gives any clues. I do remember adjusting the toggles, as per the instruction book.

Many thanks
Barry

[Tony Fearn]

Hello Barry.
Jeremy has suggested an interesting hypothesis.
Above is a scan of the relevant parts of the clutch assembly.
2042x6 is the spring on the end of the shaft that keeps the clutch thrust race from going too far backwards.
It can't drop off of course when it's all together, but it might just be able to go too far back if the ring isn't present, as Jeremy suggests.
The blurb says that it is a 'clutch centre spring ring', (and by the way it used to cost 2 old pence!).
The information booklet says that there should be 1/2" play on the clutch pedal, so there's something wrong somewhere if you need 2".
If it is missing, and you can't get a replacement from JCS Ltd., give me a ring, I probably have a spare somewhere.
All the best,
Tony.

[Tony Fearn]

I imagine I put it on with a compressed air Impact Driver, rather than wedgeing the crank and using a bar.

That's one method if the cylinder and con-rods are removed. I used a stout piece of oak or similar hardwood.
I've a feeling that the flywheel nut uses the same size of spanner as the nut fixing the crankshaft sprocket in the timing case.
It's a long time since I put an engine together, but seem to remember having a large box spanner on the crank sprocket nut, and a spanner on the flywheel nut (and a big hammer to boot). There's a plain washer under the flywheel nut.
Righty-tighty on the crank nut = righty-tighty on the flywheel nut.
Tony.

[BarryCambs]

Thanks Tony, that's very helpful. Thankfully it looks like the engine is not coming apart, but I'm sure I can get it all tightened up and maybe go with a bit of locktight this time around. Alongside the socket are a pair of 1/2W studs I used with a heavy duty puller to get it off and I seem to remember it being pretty tight!

All I can do with the clutch is go through everything with the parts book. I didn't do anything to the gearbox other than change the oil and I'm wondering if rather than something in the clutch moving backwards towards the release bearing as speed picks up, it could be something in the gearbox moving forwards and pushing the release bearing towards the clutch! Two inches on the pedal is probably only a few mm on the release bearing.

As you'll remember, pretty much every component on the car had been comprehensively botched, so it would seem probable the gearbox hasn't escaped and if it's missing part that controls the end float on the input shaft . . . . . . .

It's a 4 speed gearbox and I do have a spare. I had planned to rebuild the one in the car making one good one out of the two

Thanks again for the scan

Barry

[Jeremy]

The scan shows the part I meant, thanks Tony - Barry you can see if its there without taking anything apart. Picking up on your point of it being a gearbox issue I can't see how that could be the cause. The gearbox input shaft would just slide inside the clutch further. If the front bearing retainer was loose then the gear would disengage and everything would stop.

A proper conundrum indeed - lets hope its the C clip thats missing!

Cheers
Jeremy

[BarryCambs]

Given my experiences with the rest of it, I'm going to say I'd be surprised if that clip is there. I'll have a look this weekend. I'm still not sure why the problem should be speed related though. The engine and gearbox are from 1934, the car is 1929, so the clutch linkage is I assume grafted from the donor car. I think the earlier engine with cone clutch has the clutch pedal mounted directly on the shaft through the bell housing. I did see in the service spec it says 'it's important the the two adjusting rods are equal lengths' and I doubt that very much. The clutch does work fine.

Thanks
Barry

[Tony Fearn]

Here's another scan which may be relevant to this post.
Tony.

[BarryCambs]

Thanks Tony - thats a very useful picture. Where is it from? It's a while since I looked at it, but I don't recognise it from the owners manual.

Barry

[Tony Fearn]

that's a very useful picture. Where is it from? It's a while since I looked at it, but I don't recognise it from the owner's manual.

It's from this site, in the Technical Library / PreWar / 1935-1939 Maintenance Manual, that Bryan Walker kindly scanned for us, K.C. doing the honours of putting it in there.
It's worth having a look at everything in there.
Tony.

[BarryCambs]

I finally got around to taking the engine and gearbox out today. In truth, I've been a bit distracted by starting to get out with friends on motorbikes for the first time in 15 years!

The C clip is missing and I guess has been for a very long time. One of the toggles was way out of adjustment compared with the other two and I'm guessing that's not helping. I'm sure I remember adjusting them in the car, rather than on the floor, so it could be the thrust race moved while I was doing it given the C Clip was missing.

Reassured I'd probably found the clutch problems, things took a considerable turn for the worse. Checking the flywheel nut I assumed was loose revealed it wasn't. I could however move the flywheel several degrees on the crankshaft. I took the nut off, which is tight all the way due to damaged threads and it's clear the taper is damaged, this being historical, rather than being caused when it came loose. I was going to check with Engineers Blue, but there didn't seem to be much point. The nut, flywheel and crank all show chisel damage (also evident on pretty much every component on the car) and the rear of the flywheel also has damage from where someone has tried to hammer if off in the past.

I tried the flywheel by hand on the old ex boat engine I rescued and it fitted nicely. I have the crank from that and another spare from somewhere else, but they both need the big ends doing. Feeling more than a bit disheartened, I pushed everything back in the garage and serviced the motorbike instead.

[BarryCambs]

The search continues to find a single part of the car which hasn't been butchered in some way The rough patch on the crank shown in the photo is only on one side, its not like this all the way.

The flywheel from the boat engine had the starter teeth virtually worn away on one side, so something must have been very out of true.