Clutch adjustment (Slipping test)

[mickeytwonames]

Is there a good test to see if a clutch is slipping (1954 MkII) and what can one do to:
1) Clean it if it's dirty
2) Visually check it
3) Adjust it for maximum grip?

Many thanks

[simmitc]

It's really quite obvious if the clutch is slipping - the revs rise quickly, but the car accelerates slowly. To inspect the clutch you have to remove either the engine or the gearbox (personal choice, but I'd go for the engine. If the friction plate is contaminated by oil, or worn very badly, then replace it. Cleaning is a lot of effort for little reward. Resolve why the plate is dirty before fitting a new one, or the same problem will recur. If the problem is with the pressure plate then there is a theoretical adjustment, but the fault is likely to be weak springs, and again replacement is the best option.

[robedney]

More info please If the engine and trans are in the car, there's no way to visually inspect the clutch disc or clean it. The actual "grip" is a function of the springs in the pressure plate. What you can adjust is the free-play, which means that you ought to have somewhere around 3/4" at the top of the pedal travel that does nothing (assuming that the pedal return spring is attached under the car).

One way to check for a slipping clutch is to run the front wheels up against a curb, set the handbrake, shift into something like 3rd gear, accelerate some and slowly let the clutch off. The engine should stall. If you can keep the engine running once the clutch is released, it's slipping -- and it's time to replace it. This is a quick test -- done quickly -- as you don't want to burn the disc or the flywheel!

Ooops -- concurrent post with simmitc!

[mickeytwonames]

Thanks, I will check the adjustment and run the curb test

[bmcecosse]

Better to do that test in a nice open area with the handbrake pulled up HARD. 4th gear - rev up hard and then just lift your foot straight off the clutch. If it doesn't stall pretty much right away - it's slipping......

[MarkyB]

The slipping test is a bit harsh and isn't going to do the clutch any favours.
If the clutch is on it's way out it will first show as slipping in top when trying to accelerate.
Like driving on ice, you need to match the engine speed and road speed, revving the nuts off it will get nowhere.
The pressure plate can't be adjusted, you just need to make sure there is some free play at the clutch pedal.

[bmcecosse]

If the clutch is good - it won't slip at all in the test - the engine will stall right away.

[robedney]

If the clutch is good - it won't slip at all in the test - the engine will stall right away.

Yup, and then you know for sure. It's been my experience that some people have a lot of trouble realizing that their clutch is slipping until the car won't move, smoke is coming out from the underside and the smell of burning lining and hot steel is singing your nostrils. By then the flywheel is going to have to come off for resurfacing (or replacement) and the springs on the pressure plate may be worthless. This reminds me of an acquaintance who found the red oil light on his VW bug so irritating that he hung his baseball cap over it. He made it halfway across the Golden Gate Bridge before the engine seized. He paid a very dear price to learn what the light meant, but made the mechanic and the tow driver very happy.

[mickeytwonames]

Many thanks for all the replies - My clutch is slipping and I'm going to replace. I've got the original workshop manual but is there anywhere a check list of what you need
i.e How many part need to be replaced.
Also, is it an engine out job? and how long should it take (given that no gremlins get in) I'm reckoning it's a weekend job. Also, is there anything else worthwhile replacing while I'm about it?
Many thanks in advance you Morris men

[bmcecosse]

Are you sure it doesn't just need adjusting? Is there some free play at the pedal?? Yes - easiest to pop the engine - replace the centre plate and the carbon thrust. The pressure assembly is usually fit for further use - but do inspect it.

[mickeytwonames]

Many thanks
I've got 3/4" play on the pedal
How much adjustment is there on the clutch linkage that on can play with?
the slipping is not TOO BAD but it wont stall in 4th (kerb test)

[bmcecosse]

As long as there is free play - that's it. Sounds like oil on the plate - is there oil dripping from the jiggle pin?

[rayofleamington]

If the clutch is good - it won't slip at all in the test - the engine will stall right away.

Having worked for LuK (produces 1 in 4 vehicle clutches in the entire western world) I'd agree with the test, but with one major warning:
If the engine doesn't stall, stop ASAP (within a couple of seconds maximum). The longer you carry on, the greater the damage to the clutch and within 10 seconds you can remove a massive proportion of the clutch life!!

All the energy coming out of the engine will be turned straight into heat and when the clutch is over 300°C it will loose material like scraping a knife over bunt toast.

[mickeytwonames]

What's and where is the jiggle pin - Can't find it in my workshop manual (pdf) IF IT'S OIL CAN IT BE CLEANED OFF?

[bmcecosse]

The jiggle pin hangs down from the hole in the base of the gearbox bellhousing.... It's there to jiggle about and keep the hole clear -while keeping small furry animals out. Oil dripping from there indicates oil leaking through from the engine rear bearing - or to a lesser extent from the gearbox front bearing. I agree completely with Ray's comment re not letting it continue to slip during the test (or indeed at ANY time) , however that couple of seconds may help to 'fry' off any oil - although it's pretty much wishful thinking, and would in any case be a temporary relief only.

[MarkyB]

Thanks rayofleamington, that's just what I was trying to say earlier, if the clutch is a bit marginal this test is likely to knacker it in short order.

[robedney]

Thanks rayofleamington, that's just what I was trying to say earlier, if the clutch is a bit marginal this test is likely to knacker it in short order.

No more than driving it up a hill will. Remember, you're not trying to cook the clutch -- just see if it will stall. And -- no matter the cause -- if it's properly adjusted and still slipping in 4th it's got to come out soon.

[robedney]

It's easier to pull the engine -- saves you miserable time under the car trying to align and wiggle the transmission back in without messing anything up. If want the parts on hand when you do the job, you need a disk, pressure place, throw-out (release)bearing and pilot shaft bushing (sometimes optional). If you've got a parts supplier nearby, you may be able to inspect and re-use the pressure plate. You're also going to need to have a close look at the flywheel for any bluish areas and/or heat cracks. If you have some of that, post back here (preferably with a pic of the flywheel). A weekend should do it. It can be done in a day, but it's easier to do a day out and a day back in. Having a helper at times is also a good idea. You'll need some sort of alignment tool to get the disk centered properly before tightening down the pressure place. If you're going to do the pilot shaft bushing, you'll need some way of pulling out the old one (cheap puller). Don't forget a finger full of grease in that bushing before reassembly!

Many thanks for all the replies - My clutch is slipping and I'm going to replace. I've got the original workshop manual but is there anywhere a check list of what you need
i.e How many part need to be replaced.
Also, is it an engine out job? and how long should it take (given that no gremlins get in) I'm reckoning it's a weekend job. Also, is there anything else worthwhile replacing while I'm about it?
Many thanks in advance you Morris men

[MarkyB]

Remember, you're not trying to cook the clutch

Easy to say but what do most people do when the wheels are spinning on ice? Rev it some more, followed by rev it even more.
Not the way to get best traction but it's what people do.