Hi everyone, I have a 1929 Chevrolet Imperial Sedan, 194 c.i., 6-cylinder, 3 speed. This car is being re-assembled after frame was powder coated and remainder of parts cleaned, coated, painted as necessary. I’m having problems getting the clutch to function - clutch doesn’t move. When all 3 components are assembled the throw-out bearing sleeve sticks out only 5/16" from the pressure plate. Here are the part numbers and pictures of what I have. Any help getting clutch operational or knowledge regarding part compatibility would be greatly appreciated.
Flywheel: Part Number 835767 Date Code E 27 9 9 3/16" Machined, Recessed Surface
By no means am I an expert on this generation clutch. On the other hand I have been in similar situations with lots of assemblies.
- Did the clutch work properly before you started your work? - How did you confirm that the height is not great enough for the clutch to engage and dis-engage? - Is the face where the throw-out bearing runs worn excessively? - Is the clutch disc the correct thickness? - Did you have the flywheel faced where the clutch disc operates? If so, did they take a similar cut on the mounting face where the pressure plate is attached?
Hello PaulAmoroso, You too have a mystery flywheel part number. See chat thread #161360 01/08/10 05:44pm. It may be in regards to early versus late 1929 production. Your riveted disc seems appropriate, although aftermarket replacement probably would not have the original Chevy part number for comparison. Your pressure plate COVER part number 835821 is listed for 1929. You may want to look at: chevy.oldcarmanualproject.com. and scroll to: 1929-1932 Chevrolet Master Parts Price List for Six Cylinder Models. See the index for flywheel and clutch page numbers. I=1929, U=1930, Ind=1931, C=1932. As far as functionality goes, I can't help, but with an exploded view of the assembly, you should know if you're working with everything required.
1. Yes - Clutch worked properly over 10 years ago. 2. I confirmed the height wasn't great enough since there is an excessive amount of free play in clutch pedal. 3. Not that I can tell throw out bearing (Carbon - Old Style) or throw out collar sleeve. 4. I believe the clutch disc is the correct thickness (Disc still has writing on flywheel side) 5. Flywheel was machined, but not cut where pressure plate mounts. Note - When clutch assembly was removed, there were two fairly thin flat washers between pressure plate and flywheel on mounting bolts. Any idea why?
Hello PaulA, So it looks like you had the friction surface ground. Many shops now do not have an old timer around to teach them about the intricacies of these old engines. So in this type of installation with how the pressure plate works you have to take the same amount of material off of the mounting flange as you took off of the friction surface to maintain the designed geometry. When you look at it - it will make sense. By just grinding the friction surface they effectively moved the disc away from the pressure plate. A more modern pressure plate works on an entirely flat surface so the geometry always remains the same. If they measured it before grinding that is great, you know how much to take off. If not you will have to do some trial and error and find another member with their clutch out so they can give you a ball park as to the distance of movement there should be at that location. As a starting point it is probably only .020" to .030".
How worn are the ends of your pressure plate arms, and where they mate together with the sleeve? In the picture it looks like your pressure plate mounting bolts are not tight either. When those are pulled down it should make a big difference. That is the dimension you will need to actually measure, and compare to another assembly.
One last thing I would recommend is to have the whole assembly minus the disc spin balanced. It will only go together one way.
Let the forum know what you find out. I guarantee some one has, or will have the same problem.
I had a similar experience with a disc I purchased on Ebay that was advertised as for a 1929 Chevrolet. It looked like my old one, " however when the clutch didn't work I compared it to my old one and found the hub was 1/8" further offset than the original.
The washers are possibly to adjust for an improperly machined flywheel . I have washers added under the mounting bolts of the pressure plate on my 32 as without them it was impossible to get the disc released. If your flywheel did not have the plate mounting surface machined AND you have washers I would first remove the washers and check operation and if still not satisfactory then proceed to try and determine the correct amount to machine from the flywheel. Needless to say this is after you verify that the release levers and mating surfaces are within specs.
Hi Paul I went through this with a customer about month ago. What it looks like to me from the pictures you posted, you have a 1930-31 Chevy pressure plate and cover assembly made for the 9 inch car clutch and 10 inch truck clutch. The 1929-31 used the same clutch pressure plate cover but the pressure plate themselves were different for 1929 and 30-31. The original flywheel for a 1929 only used a 9 inch clutch for both the car and truck. This is why the flywheel has a stepped surface in it. What is happening I believe is that since the flywheel has been resurfaced only in the 9 inch area of the flywheel and if the mounting surface was ground off where the pressure plate mounts the same distance as the face of the flywheel, the clutch disc is piloted deeper in the flywheel and now the pressure plate which is 10 inches is bottoming out on the step in the flywheel. This would move the pressure plate farther back into the cover when bolted to the flywheel causing the ends of the fingers to go down farther toward the flywheel and that is why you don't have much for travel left on the throw bearing sleeve and probably why there were shim washers between the pressure plate cover mounting and the flywheel when you took it apart. I think if you grind or machine the step out of the flywheel and make it totally flat faced, that will solve your problem. The other alternative is get a different flywheel to match the pressure plate assembly you have or find the correct pressure plate assembly with 9 inch face instead of the 10 inch face to match your flywheel. Attached is a picture of a 1928 Chevy pressure showing the face which is similar to the 1929 one which is only 9 inches in diameter on the machined area.
Bob, Thank you for phrasing what I was describing to Paul in a different possibly more understandable way. You are correct in the statement about the flywheel for '29. If his clutch disc fits completely into the 9" recessed area of the flywheel then he only has to have the outer mounting lip ground down the same distance as what was machined off of the flywheel friction surface. If that disc is a 9-1/4", which is a common size, it will not work. If they machined so much off of the friction surface that the pressure plate bottoms out on the raised outer surface the clutch disc could contact the flywheel bolts. The clutch disc is 5/16" + -. Make sure you are using low profile bolt heads when mounting the flywheel.
Paul, if you take the flywheel back in to the machine shop to have the rest of the friction surface machined you will have to temporarily drive out the alignment dowels installed in the flywheel. To remove them I think they are driven in toward the interior of the flywheel so that if they get loose somehow the centrifugal force will keep them from causing a problem. Make sure to reinstall them so that it ensures the flywheel and pressure plate can only be installed in one position. If you did not do it already that would be a good time to have both of them assembled and balanced on a lathe.
