The Stovebolt Site Forums The Shop Area Engine Shop installing new clutch disc

I'm proceeding with the clutch replacement before the snow flies - The truck shop manual isn't super clear on several things. For example, the clutch disc must face one way or the other. Here's a pic of my old one:

http://edj.net/mc2012/1953clutchdisc2.jpg

The center hub sticks out more in one direction. Which face should face the engine? Also, is there any direction that the little pilot bushing should go in? Got a new one, and the opening is slightly flanged only on one end.

The flywheel and clutch pressure plate surfaces are not damaged, but they are dirty - what can be used to clean them?

Finally, when I center the clutch disc before tightening the nine bolts all around, is there a trick for keeping the clutch disc centered? I don't have the special centering tool. Can you make a wooden dowel or something? Many thanks,

Hy Colorado51three-quarter, most clutch discs will only fit on one way, the cushioning springs on the disc will not allow that side to sit against flywheel, it will interfere with the flywheel bolts, most new discs are marked flywheel side. The pilot bearing has a radiased side, that side faces the transmission, it makes it easier for the input shaft to find its way into it. Cleaning the flywheel and pressure plate can be done with any good brake cleaner. As to centering the disc, you can do a good job just by making sure it is in the same position relative to the pressure plate all the way around. Now a note of caution, I would want to figure out what caused that damage to the disc, before I put it back in and applied power to it, chances are something locked somewhere in the driveline to cause that damage, hope that helps.

Hey 3B - thanks a million, you're the greatest - just the clarification I needed. As to why the disc was mangled, here's my theory. When I reconstructed the pieces, it measured a full 11 inches across. However, the diameter of the pressure plate itself is not a smidge over 10 3/4, with little room to spare before you hit the housing wall. It even looks like there's some scraping against the inner wall of the housing. I'm guessing the wrong size disc was installed by the P.O. and it was instantly mangled. I ordered an unused NOS clutch disc specified as 10 3/4"

I wonder, though - If there is a lock in the drivetrain do you think it would have to be in the back axle, since the flywheel spins? The truck rolled freely.

That said, there is a continuing perplexing problem. The engine runs strong with the clutch and trans removed, but the rattling sound that I thought was the clutch disc pieces is still happening! It seems to come from the area of the flywheel, near the starter, as if there's a bolt or a nut ratttling around in there. I could record it if you want to hear it. However, the flywheel is spinning fine.

Thanks again!

What size engine and is it a three speed? I had a major issue with my disc on my 261. The new disc I bought from a repop seller was actually marked incorrectly as the flywheel side. After pulling the tranny twice, I found the right one at NAPA and it went in without a hiccup. You can usually find a pilot tool to center your disc from one of the local FLAPS guys. I used an input shaft from one of my old trannys. Some information on the incorreect disc issue on my webshots albums.

http://community.webshots.com/user/geezer

I had a rattling sound that turned out to be the starter drive mechanism. When I first tested my motor before I did a rebuild, the collapsed cab was causing the starter gear to be partially engaged. As I found out years later when I put everything back together, it damaged the starter drive.

49Geezer,
It's a 235 4-speed. Thanks for the photos, that confirms the direction.

Truckernix,
Yes, maybe it is the starter gear. When I first installed this old starter, it had some trouble retracting after the engine started. The starter does seem to be spinning a little when the engine is running. Maybe that's it - thanks!

I didn't get the message on what is the actual orientation of the clutch plate.
Does the extended centre tube face towards the engine; or towards the transmission?

I'm trying to fit up my clutch and transmission on my 42-45 3/4 ton and even though I align the comression springs with the centre hole, using a pilot guide cut from a junked transmission, the three speed gearbox doesn't want to go all the way home, I'm about one inch from making it.

I suspect the clutch is facing the wrong way....:)

Zacca,
From Geezer's photos which show the *wrong* side labelled, it seems that the extended center tube should point toward the engine.

http://community.webshots.com/user/geezer

Seems I missed the URL to Geezer's Webshots, which gives a complete instruction on what's happening inside down there.
Excellent guide, highly recommended.

Thanks, I'' look and see what I have in the morning.

Zacca

Personally, I would not recommend just cleaning and re-installing the original pressure plate assembly. Reason being, the surface condition of the plate is only one component of the assembly. The plate springs can also weaken over time and temperature, or even crack or bend depending upon the clutch use and conditions. A week pressure plate assembly can result in premature plate wear, chattering, and slippage under high load conditions. I have always replaced the whole 9 yards, clutch plate assembly, pilot bearing, pressure release bearing, pressure plate assembly and resurfaced the rear of the flywheel. Unless of course you enjoy pulling tranmissions often, I would not short cut on the project.

The extended part goes towards the pressure plate. Having it in backwards would not keep the trans. from going in. After you got it done it won,t release though. The shaft is probably not going into the pilot brg. After you make shure the clutch is in correctly & if it won,t go in all the way hook up the linkage & have someone press in on the pedal.

Hey everybody,
Mission accomplished, my 53 1-ton is moving. I leg pressed the trans back in after replacing the clutch disc. You can read all the details at the 1953 chevy link below. Thanks for all your help.