Clutch slip when warm

Post by **Benjy** » Sat Nov 13, 2004 5:32 pm

Hello, my brother is complaining of clutch slip, to the extent that he struggled to get up our road (it's pretty steep) after a drive back from Cardiff.

I took the car out this morning and it seemed fine, it pulled up the drive with no problems. I tried letting the clutch up in gear with the handbrake on and there were no signs of slip at all. He says it tends to only get bad when the car's warmed up.

He does loose quite a lot of oil - we haven't gotten around to finding where from yet, but mostly only if the engine's running - could this be finding it's way onto the clutch if the rear crank seal (?) is gone? Would this not contaminate the plates permanently so that slip was always present?

Thought I'd ask before stripping it all apart.

Ben

Just been out to look and the underside of the g/box is covered in oil all over, even uphill from the drainplug. The bottom of the engine is clean, so I guess that must be the problem.

I seem to remember hearing that the Moggy doesn't have a rear crank oil seal, so what do I need to replace and is it likely that the clutch plates will need replacing too, or should I check them when the engine's out?

Post by **Alec** » Sat Nov 13, 2004 7:45 pm

Hello Benjy,
firstly check that there is free play in the clutch linkage, if you get hold of the clutch release operating yolk, (the arm that actuates the release bearing) there should be about 1\8" free play. If there is non that could be the problem. If the rear seal is leaking and has contaminated the lining then there is no remedy with the existing clutch. Make sure though that the engine is not overfull with oil and that the breathers are clear.

Alec

Post by **Willie** » Sat Nov 13, 2004 7:53 pm

You are correct, there is no oil seal at the rear of the crank, just
a thread cut into the crankshaft which 'winds' the oil back into the sump.
There is a hole in the bottom of the bell housing with the ends of a
large split pin dangling down. If this is dripping oil then yes, the clutch
area contains oil. This could be coming from the engine or the
gearbox. It is easy enough to see if the gearbox level keeps dropping
and if it does it must indicate a leak as that is the only way the oil in
there will disappear. The rear engine 'seal' is an ongoing problem,and
I have read of owners who have had as many as four factory re-built
engines before they got one which didn't leak at the rear. Owen
Burton has marketed a modified rear seal which,in theory, should be
perfect, but I understand it involves some serious metal working.
Reference the 'oil all over the gearbox' since the oil gets spread all
over by the draught as you are driving along the only way to isolate
the origin of the leak is to thoroughly clean off the box and then
watch it from then on.

Post by **Benjy** » Mon Nov 15, 2004 8:20 am

Alec, Mark (my brother) is constantly adjusting his clutch pedal free play because the lock nut doesn't lock, so I don't think that is the problem.

Willie, thanks for the explanation. I'd read the Haynes manuals and they really didn't explain much, at least not without having a dismantled engine in front of you to make things clear!
I have tried and tried to persuade Mark to clean the botton of the engine & box and then use paper to find the leak, I know it's not hard, but he's not very good at getting round to small jobs. Anyhow, there was definately oil on the split pin so that gives us somewhere to start.

Post by **Alec** » Mon Nov 15, 2004 11:04 am

Hello Benjy,
OK that's fine, I am a great believer in checking basics first, it can save a lot of time and money. I would suggest to Mark that it is easier to replace the damaged lock nut than constantly readjusting the clutch, for what it's worth.

Alec

Post by **Kevin** » Mon Nov 15, 2004 2:04 pm

I would suggest to Mark that it is easier to replace the damaged lock nut than constantly readjusting the clutch, for what it's worth.

With you on that point Alec, cant understand the reluctance to spend a few pence to save grovelling under the car more than you need to.

Post by **Cam** » Mon Nov 15, 2004 2:57 pm

I think the locknut is the same as the rocker (tappet) adjuster nut, so if you have on of those lying around............

Post by **salty_monk** » Tue Nov 16, 2004 9:41 am

Benjy, you say you live on a steep hill? Tell your brother to park nose down, I've heard rumours of cars that have leaked oil out of the back seal whilst parked "nose up"...
Might not work but as it's not much hassle it would be an interesting experiment to see what happens to his oil consumption!!

Post by **Benjy** » Wed Nov 17, 2004 3:43 pm

Cam, are you sure it's the same as the tappet adjuster nut? I hunted for one for ages, everyone told me they were 1/4" BSF including several MM parts suppliers, but they're not. The closest I found was a 7mm, but that wouldn't thread poperly (I wonder why). One of the tappet adjusters on the pickup is still using some odd nut I dug up and a thick washer. If you're right, I'll see if I can get hold of a couple of clutch adjuster lock nuts instead!

Ben

Post by **Cam** » Wed Nov 17, 2004 4:08 pm

Well............. I tried to order a locknut from the Morris Minor centre in Birmingham and they said they did not stock them, but they would send me a tappet adjuster nut as they thought they were the same. I tried it and it fits OK. In fact it's been on my car for a good while now.......