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clutch pressure plate

Posted: Sun Apr 21, 2019 6:50 pm
by minijojo
again i have a problem with my clutch pressure plate. I hear a grinding noice witch comes and goes with every turn of the crankshaft. Sometimes when operating the clutch a hear a sound as if a spring relaxes with a bump. Engine out and i saw the problem. The bearing thrust plate was mot centred and and was not sitting flat because one of the anti rattle spring and the release lever were not operating correct. The release bearing and the bearing thrust plate have not touched on the whole surface, clearly to see due to uneven marks.
this is the second time i got this issue

there are serveral options now

try to get a working clutch pressure plate by dissassenbling the two failed ones and assemble one with no visible faulty parts?

buy a new quality 1098 clutch?

What clutch pressure plate should i buy best?

Would be nice to here any hints or tips

Re: clutch pressure plate

Posted: Sun Apr 21, 2019 7:15 pm
by philthehill
I would remove the release bearing thrust plate and check the height of the release/operating fingers. They should all be the same height when the centre plate is in place.

Make sure that the thrust plate is correctly located in the three slots of the release/operating fingers. Quite often the thrust plate flips out of one of the slots when fitting the gearbox to the engine.

The thrust plate will clean up with a piece of medium grade wet/dry on a piece of glass & rotating the plate in a figure of 8 motion.

A photo of the release bearing would not go amiss.

Re: clutch pressure plate

Posted: Sun Apr 21, 2019 8:40 pm
by minijojo
Hi Phil,
thanks for your comments,
here is the release bearing that was installed
release bearing.jpg
release bearing.jpg (893.23 KiB) Viewed 1251 times
this is the backside of the bearing thrust plate. You can see that the releae levers are not in the same position. If i operate it manually it mostly don´t comes back to a normal position
baering tthrust plate backside.jpg
baering tthrust plate backside.jpg (1.82 MiB) Viewed 1251 times
would tryout your tips tomorrow
thank you again

Re: clutch pressure plate

Posted: Mon Apr 22, 2019 7:09 am
by philthehill
Thank you for posting the photos of the thrust bearing. All seems to be well there.

Looking at the underside of the pressure plate the lower left release finger is not sitting on the release bearing thrust plate the same as the other two and it appears to be picking up on the finger to thrust pad interface.
Check the height of the fingers, clean everything up making sure that every interacting surface is smooth, round off the end of the fingers so that there is no chance that the fingers can dig into the underside of the release bearing plate. and try again.

If you need details in addition to those in Section E10 of the BMC Wksp Man as regards checking the finger height please come back on here.


Re: clutch pressure plate

Posted: Mon Apr 22, 2019 5:19 pm
by minijojo
next day, next try
i inspected the whole clutch, found nothing to worry about. No broken springs. All seams to be in the correct position. i noticed, that the pressure plate was not parallel to the housing (not the same level but not parallel). I corrected this by adjusting the eyeboldnuts. After that the level between the housing and the pressure plate was all around the same. The bearing thrust plate was nearly centered. Operated the clutch manually, all seems to work and look fine. mounted driven plate assembly and cover/pressure plate by using a clutch alignment tool, fastened the screws crossover round per round untill the housing gets contact with the flywheel. Turned on all screws.
Noticed that the bearing thrust plate is not centered after mounting. see picture.
stillNotcentered.jpg (943.83 KiB) Viewed 1170 times
Now i guess the spring constant of one of the springs is not (more) correct and this brings the bearing thrust plate out of the centered position when under light pressure.
i don´t wont to try out mounting the engine end have the same problem as before......

i bought and installed the clutch in August 2018 and drove about 1000 miles since then without any problems

Re: clutch pressure plate

Posted: Mon Apr 22, 2019 6:50 pm
by philthehill
I notice that the finger adjusting nuts have not been staked into the slots of the adjusting bolts. They must be staked after adjustment.
If they are not staked they will come undone and misalign the release bearing thrust pad.

The fingers must be adjusted correctly as per the manual.

That release bearing thrust plate does need to be cleaned up otherwise the carbon thrust is not going to last long.

Re: clutch pressure plate

Posted: Wed Apr 24, 2019 6:59 am
by Declan_Burns
I think Joachim's problem could lie deeper. The section E10 in the workshop manual requires special tooling (18G99A) which nobody has. This is the second clutch he has fitted where this problem has appeared. He still has the old clutch. Perhaps the bush in the lever out of the bell housing is worn and causing this?? His old clutch did have staked nuts. I think just fitting a third clutch is not going to solve the issue-for long.

Re: clutch pressure plate

Posted: Wed Apr 24, 2019 11:44 am
by philthehill
Whilst it is better to have the special tool 18G99A when checking that the fingers are the same height it can be done without the special tool.

All that needs to be done is for the flywheel to be laid flat, the driven plate placed central on the flywheel, the pressure plate to be fitted and the release bearing thrust pad removed.
The heights of the fingers can now be determined by using a depth gauge inserted in the slot and the distance measured from the clutch driven plate to the top of the fingers.

The driven plate replaces the spacers of the special tool and the depth gauge replaces the height finger.

The above if care is taken can be done with the flywheel/clutch assy fitted to the crankshaft.

Whilst not 18G99A - clutch adjusting tools similar to 18G99A are sometimes available on 'e' bay. There have been two of the below offered just recently and usually sell for around the £20 mark.
clutch tool.jpg
clutch tool.jpg (317.1 KiB) Viewed 1058 times

Re: clutch pressure plate

Posted: Wed Apr 24, 2019 11:57 am
by Declan_Burns
Thanks Phil,
I am sure Joachim can tackle that. Any idea why the same problem could have occurred twice within such a short time?

Re: clutch pressure plate

Posted: Wed Apr 24, 2019 12:06 pm
by philthehill
Unless I stripped the clutch pressure plate and examined it for faults it is hard to say but the remedies that I mentioned in my post above should be actioned.

Here is a dummy flywheel tool currently for sale on 'e' bay ... SwRcZcaXxQ

A bit more than £20 but looks to be complete and in its original box.

I regularly used one of the above clutch setting tools back in the day when you re-built clutches and not just replaced them.

Re: clutch pressure plate

Posted: Wed Apr 24, 2019 6:18 pm
by minijojo
Many thanks to Phil and Declan for your help, hints and tips
just a few facts to my car. I changed my gearbox from smooth case to ribbed case in March 2017. Changed engine backplate (used), flywheel (used), clutch (new) all bolts, nuts and flywheel bolt lock washer (new), clutchfork (used) to the 1098 version on my 948 engine.
Because of a noisy clutch i change the clutch again in August 2018. One and a half year is not a long time for a clutch

I checked the bush of the clutchfork now, it had a little play but not enough to cause problems (my assessment). I changed the bush for peace of mind. Now there is no play in the clutchfork.

I ordered a used clutchfork just to see if it looks the same as mine and if the lever is possibly bent. I am almost sure i got the right one build in.

I phoned a few dealers and asked for the manufacturer of the clutch sets they are selling. and if they have any problems.
Most of them sell the B&B clutch and can not report any problems

i am a little bit unsure to adjust the clutch, but i will try to do it the way Phil descibed it. It is always good to follow advice and give the repair a try before changing parts.

i never thought a clutch could cause me so much trouble. The question i asked myself is, what causes the clutch to fail?

is it the person who carried out the job?

Hope to find a solution until next weekend, so that i can restore the engine again. Have still a full time job and work on the Minor after work or at weekend
will keep you informed

Re: clutch pressure plate

Posted: Wed Apr 24, 2019 6:39 pm
by philthehill
Your clutch has not failed - it just needs a bit of tender care which it may not have got when manufactured.

Get those release fingers all the same height, remove any burs or rough interface contact surfaces and set the clutch linkage on the plus play/clearance side.

Hopefully then all will be ok.

Re: clutch pressure plate

Posted: Sun Apr 28, 2019 7:52 pm
by minijojo
Weekend gone, all work done for today, noise still there

i dismantled the bearing thrust plates from the two used Clutch Cover/Pressure Plates a have and cleaned them. Clearly to see that there is some material removal caused by the fingers. no 1 is blue from heat so i would not use it. No 2 has very much material removed. I thought about cleaning and straightening that with a a file. But i was not sure if only the surface is hardened and i would damage the surface
Plate1.jpg (1.27 MiB) Viewed 947 times
Plate1.1.jpg (1.5 MiB) Viewed 947 times
Plate2.jpg (1.38 MiB) Viewed 947 times
Plate2.2.jpg (1.36 MiB) Viewed 947 times
I will give it a try next time
The clutch operating fork was bent, so i mounted the new used one
Clutch operating forks.jpg
Clutch operating forks.jpg (740.89 KiB) Viewed 947 times
I decided to take a new clutch set. Got i good price from a local dealer. Engine in again, test drive

engine runs well clutch is operating fine as should, but i still have this damed noise. Not when accelerating but when running normal without accelerating there is a scrapping. grinding noise. I can not hear from where the noise comes exactly

I do not think it is the gearbox, I will check diff next days, my be run out of oil? But there is no oil leak to see at the rear axel….

will keep you up to date

Re: clutch pressure plate

Posted: Sun Jun 02, 2019 11:15 am
by minijojo
a few pictures to continue....

when checking the diff oil i noticed a broken rear spring......
rearspring.jpg (441.68 KiB) Viewed 840 times

after troubles with removing the front spring hanger bolt I noticed the broken rear axle mounting brackets on both sites

rear axle mounting bracket.jpg
rear axle mounting bracket.jpg (996.03 KiB) Viewed 840 times

the new springs are installed now
by a lucky circumstance I could get a used axle. I am currently rebuilding the used axle
Exchange Axle.jpg
Exchange Axle.jpg (1.29 MiB) Viewed 840 times
I am glad that I found the damages, that could have caused some serious problems.
Hope my Moggy will run again without any indefinable noise when finished all that work
Once again, thanks to all of you for your helpfull tips

Re: clutch pressure plate

Posted: Sat Jul 06, 2019 9:11 pm
by minijojo
just to to dissolve the mystery of the last noise, here it is
Crankshaft Pulley.jpg
Crankshaft Pulley.jpg (1020.84 KiB) Viewed 702 times
happened 40 kilometers after testdrive with the new rear axle.......

Re: clutch pressure plate

Posted: Sun Jul 07, 2019 11:16 am
by philthehill
A common fault with the multipiece riveted pulley.

I would recommend that you replace with either a solid pulley or my preference is for the damper pulley.

Re: clutch pressure plate

Posted: Sun Jul 07, 2019 7:38 pm
by minijojo
Thanks Phil for your tip.
I was lucky and could buy a used Austin pulley at a good price...., i was told to remove the dumper, and then it should fit.
hope that once this problem is solved, I can drive again