Parkera

Hi Max, Thank you for your post regarding the alignment marks. It really helps to know WHY things are the way they are. I looked thoroughly at the end of my crankshaft and I could not find any alignment marks as you describe (although I did see a pair on the top right rear of the block which have to have some other meaning). I also looked carefully on the clutch housing, but couldn’t find any there either. But as you can see from the photo in my first post, I believe it has been machined to remove wear, the kind similar to what to what has happened on the end of my block. Since I couldn’t find any marks, but your explanation told me why they were there, I measured the trueness of the clutch in the bearing with it installed on the crankshaft in either orientation. While the runout was 0.020” (who is to say the housing is perfectly concentric), it was the same with either orientation, meaning there was no “adding” or “subtracting” caused by the trueness of the bearing. As to the 0.045” wear on the block, I believe it was caused by the fiber washer being in direct contact instead of bronze. Since the engine has been restored not too many miles ago and runs absolutely perfect, tearing the engine down and mounting the block onto a lathe and turning it down is not an attractive option. I have to think of some alternate. If anyone has any good ideas, I’m open to them. When I pulled the clutch apart, I think I found the reason for the slippage. I believe the clutch plate tabs were getting “hung up” on the steps on the rear clutch housing, not allowing them to fully engage each other when the clutch pedal is released. I can mill a new set of ½” slots in the housing which will eliminate the steps. It is interesting that each tab on the clutch plate stack has worn to a different width. All three tabs and their respective slots in the housing have a similar amount and type of wear. Otherwise, the plates are in good condition and do not show any signs of bluing. I’m debating if I need to have new clutch plates made. The tabs are certainly strong enough as they are, but there would be some radial movement each time the clutch is engaged. Does anyone have any thoughts or opinions?

Hi David, Ken, Thanks for your replies. I recall seeing this photo on one of the threads and was surprised to find only two washers when I removed the clutch. Judging by the wear on the engine block and that the wear matched the fiber washer perfectly, I suspect the last restorer only put in the two. Perhaps the 3rd one was worn completely away when he restored the engine and didn’t know any better? Do you (or Ken) have any idea of what thickness each of these washers should be? They look like about 1/8" or a bit under in the photo. Is it highly critical? I checked the transmission bushing for wear against the main shaft. The clearance (difference) measures about 0.007” and appears to be round. I also checked the clearance between the main shaft and the rear of the clutch and it too was 0.007". Some wear, but not to the point where I think I have to replace them at this time. I didn’t have to take the transmission apart since I could reach the bushings with a telescoping gage. The service history of the car indicated some work was done on the transmission in the mid-eighties, I assume this bushing was replaced at that time. Ken – Both the clutch slots and crank keys appear to be symmetrical, so I’m not sure why the rotation of the clutch when reassembling would make a difference, unless of course I don’t know where to look for a difference (or the design was altered slightly from 1910 to 1911). The main shaft does have a “front” and “back” orientation, and is so marked “F” and “R”. When I was removing the main shaft from the clutch I noted about 1/16” of each key end was worn down to the diameter of the shaft along with some wear on the shaft itself. When playing with it, sometimes it would not seat all the way in. If it was hanging up, I suppose that could be a cause for the clutch slipping. Each key was also worn on the “drive” side, which you would expect. Are those pins that hold the keys in the main shaft? Looks like it is time to take the clutch apart and examine it for wear and/or damage.

Hello All, I’m almost embarrassed to say that, after 2 years of ownership, I have finally found the time to delve into my 1911 Model 20. After a test drive, the clutch seems to be slipping when I shift from 1st to 2nd. It shows up most on a small grade where, after completing the shift with the clutch fully engaged, the engine speeds up (from acceleration), but the car is slowing down (from gravity). Eventually, by letting off the gas some, the engine and speed of the car seem to get in sync and acceleration seems normal enough for 2nd gear on a small hill. I noted that sometimes, in neutral, there seems to be a slight rattling from the clutch/transmission area. It almost sounds like large washers rattling. This is an intermittent sound that only happens once in a while. I’m not sure if this is related to the clutch slipping or if it indicates a second problem. Also noted, when I press hard on the clutch pedal (in neutral) the engine will slow down some. From other threads on the forum, it seems this is due to worn thrust washers between the engine and the clutch. When I pulled the clutch off the engine, there was only 1 bronze washer (0.052” thick) against the clutch pack and 1 fiber washer (0.030” thick) against the engine block. There is about 0.045” of wear into the block. Because the car has had an older cosmetic restoration and at a separate time, the engine was restored with some work done on the transmission, I suppose anything and everything is suspect. Any help in guiding me to fixing these problems would be appreciated.