I am re assembling my transmission. I am at the point of pressing on the clutch drum onto the transmission shaft. I have two clutch drums to pick from, but I am thinking that maybe I need another one.
The drum on the left, darker one, will have to be pressed onto the shaft, whereas the one on the right can be pushed onto the transmission shaft by hand.
Yet, the darker drum seems to be mis shapened, probably from being pulled off. The drum is about 4 9/16" in diameter, but at the pulling holes, the diameter is only 4 1/2". Using a square It seems that one side wall is bent in toward the shaft hole. The lighter drum is nice and round.
Both have good keyways and set screw threads.
My questions are, how important is the press fit? And is the 1/16" out of round important. Or should I just pitch them both and find a better drum?
Get a better one. They can be had for a buck or two at most swap meets. The fit is important, and is so tight that quite often, during assembly, a burr was thrown up that makes them near impossible to remove without wrecking them. It's good that you're being cautious and checking them carefully.
Thanks for the advice. I have been looking around and you can get some used ones from the vendors for 10 to 20 dollars. I have an old transmission shaft and I'll use that to check the press fit and an outside caliper works good for checking the round. Set it for the diameter opposite the pulling holes and try the pulling hole diameter.
-The disc drum needs to be a tight press fit on the shaft. Do not install one that is not a good press fit. The key and set screw are ONLY there as an extra precaution.
-There are just as many under-size shafts as there are oversize disc drums around, so don't trust the "extra shaft" to be the same size as the shaft you want to press the disc drum on.
The original work shop service book says to tap the drum on with a driver.
If you have one too tight, when knocking it on you can drive the shaft out of the fly wheel.
I use an extra driven gear as a backer under the flywheel to prevent that upon re-assembly. The dowel pins go just right in between the gear teeth.
Steve, did you steal my trick or did I steal yours? Either way it works great.