how to tell if clutch is worn....

[wibble_puppy]

hi guys,

how can i tell if my clutch is worn and needs new parts or if i need a whole new clutch? One of the MM garages which saw the van when it was on the road said they thought the clutch was "very worn".

I'll be very grateful for any advice! please please please explain everything really really clearly using really basic language - as you all must have realised by now i have absolutely no idea yet about all this mechanical stuff, I am doing me best to learn but at present the sum total of my knowledge about the clutch is that it lives in between the engine and the gearbox.

I am going to read up all about it though.

The whole shebang is out of the van because of the restoration and the engine is separated from the gearbox, so I know that some part of what I can see is the clutch...

be gentle with me

wibble

[Alec]

Hello WP,

if you intend the van to be long term and you are not used to or want to be changing the clutch some time down the road, do it now before you put it back in. Clutches are not that expensive and can save you a bit of labour in the future.
I normally reckon that a new clutch bites very close to the floor and a worn one does not until the pedal is nearly all the way up, just as a rule of thumb.

I hope that goes some way to answering your question?

Alec

[gairlochrosie]

If you have it already out...then renew the lot...

[Matt]

My opinion too!!

[rayofleamington]

The whole shebang is out of the van

Ah well in that case it's easy as pie! You just unbolt the clutch cover and look at the disk. If it's worn down to the rivets, then it needs changing. If the rivet head is deep under the disk surface - it's nearly new. Anywhere inbetween is part worn...
When re-assembling you will need to get the clutch disk central. Some people get obsessed by this, but it's only relevant to allow the gearbox shaft to fit back through. Once assembled and you open the clutch with the pedal for the first time, it finds its own alignment anyway. You also need to tighten up the clutch cover fairly evenly - going round the bolts usually in 2 or 3 stages.

To check a clutch with a diriveable car, then get into top gear in mid revs and floor the accellerator. If the clutch starts to slip with light pressure on the clutch pedal then you're on thin ice. If the clutch doesn't slip even though the pedal can be moved a bit, then it's probably in great condition.

[bmcecosse]

Other check in car - car not moving and hand-brake firmly ON - select top gear, rev up engine, lift foot off clutch. If it slips it's worn - if the engine stalls it's ok. If the car moves off forwards the handbrake is useless - but the clutch is fine!

[gairlochrosie]

Think I got the wrong end of the thread here. I thought the engine and gearbox were already out of the car/van.

[simmitc]

And other inspections with the cover off: Check the friction plate for oil contamination - if present (usually from the leak at the rear of the crank) then replace it. Also check the inside of the cover - the big ring that pressees against the friction plate should be smooth, free from rust and with no grooves.

If the cluth is of unknown age / history then renew it - that saves a lot of hassle later.

The bite point of the pedal does not indicate wear of the clutch, merely that adjustment may be necessary. This is achieved using the nuts on the adjuster rod under the car. With the nuts almost all the way on to get proper adjustment, then the clutch is worn.

You really do need a workshop manual or parts catalogue to get a good picture of the parts involved, but in a nutshell, starting the the flywheel, relevant parts are: bronze bearing (in end of crankshaft, supports gearbox shaft), clutch friction plate (NB, fits only one way round, should be stamped (flywheel side) - this is a thinish item with cork rivetted to a metal frame. The comes the cover, the big domed metal bit. When being refitted tigten the seven bolts evenly and gradually in diagonal sequence to avoid distorting the ocver. ie, all finger tight, all to 2 ft/lb, all to 4, all to 5 etc.

Lastly, in the gearbox bell housing is the release bearing on its operating fork. Chekc the bearing, there should be a substantial amount of carbon present - if almost level with the metal mount, then renew. Also check that the fork bearing (where it pivots on a bolt) is not worn. Replacements are available, and just press in.

Outside, also subject to wear is the complete operating linkage: relay shaft, two plates, operating rod, and associated pins etc.

You have to have the whole engine / boc / clutch in the car in order to adjust it properly.

Don't worry, it's all quite simple, and much easier to just look at the thing and compare old parts with new to understand it all.

Good luck.

[bmcecosse]

Yes - I gather the engine is out - but many others read these threads, and may find the info useful.

[gairlochrosie]

bmc....Oh dont take what I said the wrong way....I fully understand that all advice given is invaluable. All I meant was, if it was me that had the engine and gearbox out...I'd renew the lot (old for new) and just hold onto any serviceable old bits...

[bmcecosse]

No - it's well worth looking at the friction plate - and the carbon thrust. If they are ok no need to waste money changing them !

[gairlochrosie]

I've always fitted the full clutch kit. Anything that involves engine out to short engine and gearbox split...always found it pays dividends to renew..never seen the point in just renewing one part to find that a couple of months down the road...its back to stripdown!

[Kevin]

Juliet an often overlooked part is the input shaft bearing in the flywheel they are only a couple of pounds and help to keep the alignment between the gearbox and engine just so and are all to often overlooked when they are quite worn and as you have it all it bits there is no better time to re-new it

[Packedup]

With a fair amount of help I recently replaced the friction plate on my car. The pressure plate had a slight "mishap" while the engine was being removed, which involved reshaping springs and hoping for the best when putting it back together.

Needless to say I went from a slightly slipping clutch to a grippy but vibrating one.

Last weekend help was on hand again, and with a new (actually s/h as it cleaned up a bit better than the new new one I got at the same time) pressure plate the car finally had a left pedal that felt as it should! The old pressure plate looked a lot better coming off than when it was put back on first time around (one of the fingers was very low, and had settled to nearly level over time), but must have been faulty as the car had always needed the full length of travel to work the clutch properly. This is with a hydraulic clutch btw.

The spigot/ flywheel bush is about £1.50 at ESM (After all that work, I still forgot to fit the new one I bought!), but a new pressure plate is £pricey, as is a complete kit. I initially bought a friction plate (OE B&B one) off Ebay for about 12 quid inc p&p and was lucky to get my hands on a cheap unused pressure plate locally when I needed one. So basically, if you need a friction plate, pressure plate and carbon release bearing you might be better off buying a kit (unless you want to bargain hunt on here and Feebay for a few months), but if the pressure plate and release bearing are OK then pick up an unused friction plate from the usual sources as it'll save you 50 quid or more

I now have a spare pressure plate and was going to take up the offer of a good s/h one from here too, but might be worth you going for that one (I don't need it, just hoarding spares!) if you're going the tight/ cheap route

Oh, and my friction plate was scuppered. Had plenty of material left (they don't come with all that much), but was black and shiny. That might be because the bellhousing and pretty much everything in it were covered in oil, from a suspected excess leak from the crank due to the previous owner running without any engine breathing! So if yours is black and shiny then it's bin fodder, and you need to sort your engine breathers before killing a new one!

[wibble_puppy]

huge thanks to all of you for your advice and careful explanations, really appreciated

i've not been so well lately so reading up about it has gone at a snail's pace, but I will get there

and thank you specially to simmitc who suggested that i unbolt the thing and bring it to this weekend's working party meeting so i can get the benefit of the assembled wisdom - I will be doing that very thing (if I'm ok to go to the meeting, d.v.)

[wibble_puppy]

have now done my reading and am off out to take the thing off the engine and have a preliminary look at it.

I'm appropriately impressed by the lengthy cautions in the workshop manual about the care with which the thing has to be taken apart: "failure to follow these instructions may result in excessive vibration at high revolutions. When a new pressure plate is fitted it is essential that the complete cover and pressure plate assembly be accurately balanced, for which reason it is not a practical proposition to fit new pressure plates unless balancing facilities are available... this unit can be dismantled, reassembled, and adjusted with the aid of an arbor press or drill press..." Last time i looked my arbor press was dying of overwatering

For later cars (which i guess includes my van) the following instructions are given: "The clutch tool 18G 99 A provides an efficient and speedy means of dismantling, reassembling, and adjusting the clutch with a high degree of accuracy." Good. Now where did I leave my clutch tool 18G 99 A?

I'm being tripped up as usual by the discrepancy in terms used by different books and authorities to describe a part, eg:

an often overlooked part is the input shaft bearing in the flywheel

I can't find anything in the workshop manual which could be "an input shaft bearing in the flywheel". Should I take it that this is the same as the "release bearing"?

thanks guys,

wibble xx

[bigginger]

Like a little piece of copper pipe - poss stuck on the g'box input shaft

[Packedup]

Not copper!

Should be phosphour bronze IIRC, to be soaked in oil for a couple of days then shoved in the hole in the flywheel (after removing the old one!).

Says the person who ordered one for the recent clutch job, and left it in his pocket...

[wibble_puppy]

ah! righto, cheers guys

[bigginger]

Not copper!

I know - but looks just like a bit of water pipe