VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1927 clutch problems continued

Pulled the clutch apart for the third time now. All I wanted to do was replace the clutch plate. It seems as if the new plate has caused the clutch fingers to drop a bit and the new steel throwout baering only had a small amount of travel to the the pressure plate housing. So I took of all the small plates which contact the ends of the fingers near the pivot and welded on a shim of one-eighth steel. Ground it down to about a sixteenth and then replaced the plates. That brought the fingers up so that the bearing sat about three eights of an inch from the pressure plate casing.
Put everything back together, the clutch appeared to have good travel. Started the engine and cannot engage gears with clutch fully depressed. The clutch is not the only thing that is fully depressed. Feel like walking away from it.
Maybe I'll just put the old oily cutch plate back, turn those plates upside down, put a new carbon throwout in and back where I started. A shuddery clutch is better than no clutch.

Aussiechev,

Can you engage gears without the engine running?

About the only other thing that i can suggest isv that you have the you have the clutch plate in back to front.

If you look at the manual, the splines on the input shaft to the gearbox has the hub for the clutch plate sliding back and forth on it. The picture in the manual shows the longer side of the hub pointing towards the flywheel side, and the shorter side of the hub towards the clutch preesure plate.

Modern clutch plates are marked." this side to flywheel".
Dont give up yet, have a break and do something to relax over the long weekend. Not fun having to take the gearbox box out again, but that is why we have old vintage cars, the challenge they bring to us.
Anyone can take the 2010 auto to the service centre ,and pick it up a day later!!

You can't put a 28 clutch plate in back to front, it has a dish in the front to clear the flywheel bolts.
I have a few pressure plates that have been modified so that the fingers can be adjusted. I can take some pics if you wish, it's an easy conversion and I've done it on my 34.
One other problem that I came across is when I had the clutch plate relined it was too thick and from memory I had a similar problem to what you describe.
The thickness on an original nos stock one I have is 8 1/2 mm.
Another problem occurs when the flywheel or pressure plate has been machined. If this is the case the fingers will need adjusting.

Also if you can tell me where in Aus you live and give me your pnone no. I might know someone who knows 28's well who doesn't live far sway that might be able to come over and have a look. Pity you're not in Sydney, we'd have going properly in no time. Send me a PM
Chris

Aussiechev,
Also , since you have replaced the carbon in the throw out collar with the bearing and throw sleeve from the filling station, what instructions was there regarding the removal of the old carbon.
Does the new bearing just run in the throw out collar , once the carbon is removed? or does it need another flat disc to be inserted to give the bearing a new running surface?

Did you try the fit of the bearing into the throw out collar to see where it would run on?

Hello Chris

You say you have pressure plates that have been modified so that the fingers can be adjusted.

This was very interested. Can post some pictures of this modify ? My -28 pick up clutch rattling when it engage.

Regards
Arvid

Thanks for your reply and encouragement Jack. Yes, I have had today off (ANZAC Day as you would know) and will attack the problem yet again tomorrow.
It is true - you can't put the clutch plate in backwards as there is a recess on one side to clear the flywheel bolts.
I did test the new bearing in the collar and it seems to run nicely without the need for any other surface. It's a bit smaller than the collar diameter but the spline keeps it centralised pretty well.
And yes, I read the spots off the instruction sheet that came with the bearing. It's a beautifully machined device and it did say the fitting was simple. The only anomoly I found was that it said remove the carbon bearing from the clamp in the collar. Well mine has the clamp but the original carbon bearing was much smaller and floated freely on the spline.

Chris, thanks for the advice and offer of help. If I lived in Sydney ..... Anyway, the modified pressure plates you speak of sound interesting and it would be good to see a picture of the conversion. I believe there may be other owners who would like to know about that mod too.
Seems to me that just 1mm difference in the thickness of the old and new plates shouldn't be a problem but perhaps that small amount translates to a bigger difference at the fingers. the new integrated bearing/sleeve seems to have exactly the same length as the original carbon + sleeve.
In answer to your question, I live near Herberton in Far North Qld. I'll send a PM as requested.

Aussiechev
if I was down there would stop by to help. Swapped my 27 clutch disc last yr (first clutch I changed in 35 years) and all went smooth. got a new throwout bearing (carbon one) also, new clutch shudders also but works great was told you need disc with springs to eliminate shudder. Throwout bearing should probably not be free floating as fork has collar seat. Maybe you have a pressure plate issue, fingers should not require modification.

I suggest you take a break, review issues and go at it again, get a friend to stop by and help.
Wishing you the best of luck
Ken 45145

Thanks Ken. I don't think there is any problem with the pressure plate.I pulled things to bits again today and checked that the bearing was sitting properly in the collar and that was OK. On reassembly I put that adjustment bracket doodad that bolts to the block in its highest position and that gave a bit more on the clutch lever. Unfortunately it also brought the brake pedal forward so I can't replace the floorboards as they were. I'm going to cut a slot for the brake pedal. The good news is that the clutch does now appear to disengage with a full depression. At least the gears will go in silently. I can't test run it yet because the engine will only run at idle. Don't know why. It's getting fuel to the carburettor. I cleaned the points and rotor but now it doesn't run at all so I must have upset something. More work ahead yet.

Take a look in the service book and see what it says about bending the disc slightly at intervals using wire. Seems I recall it was to make the clutch engage more smootly I would look it up but my glasses are at my girlfriends house and I am blind as a bat up close.

There should be an adjustment on the clutch pedel that would allow the pedel to move the throw out bearing just a little more. This would allow the clutch to release. I had to make a longer clutch pedel adjustment bolt when I put new leather on the cone clutch of the 1919 FB 50. The new leather was just a little thicker than the originel leather and the clutch would not release.

Bluezone, send me a pm as I can't get the photo load working, I used to do it ok but this time didn't work.

Ken, I don't think your clutch shudder is due to pressure plate springs. The most common cause it universal joint, tailshaft bush, worn bell etc. Another problem may be the new clutch plate, if it was and old nos one then the linings will be too hard which will cause shudder. I put a nos one in my coach but had it relined in very soft material and I could hold the Chev on a steep hill by having the clutch half way out with no vibration whatsoever
Chris