Friday, April 10, 2009

ZA50 End Play Float Measuring

Since my ZA50 (pronounced ZAH50, like short for Pizza, as in "hey lets order us som 'roni 'za") refused to roll backwards, that was nice enough to allow me to realize it was shimmed incorrectly. I have not the factory tools to measure, and even though they work very well, it isn't really a measurement so much as it is like a mechanical version of putting your fingers apart from each other on the back of a frame you want to hang up, and then moving them to the wall to make pencil marks. So with the advice of Mr. Mike Mike Naz, I went and purchased myself a machienst square, which was about $12, and a new battery for the shops digital calipers, which was $6. Oddly enough. So using the straigt edge, I was able to accurately measure the distance from the case, including the gasket, to the inner bearing race, as seen here. Credit goes to Dean, who had to take this picture twice as the first time I was incorrectly measuring the other bearing by mistake. Then using the straight edge, it gets a little trickier to measure the gear of the bellhousing, but not too difficult once you get the hang of it. Take several measurements until you can get a consistant reading. Take the two readings, subtract the bellhousing from the case measurement, and you have your end play float. Mine was .6mm with no shims. The factory specs are .05 - .25mm, which is as Chuck suggested, about the thickness of a Dr. Pepper can. Since I want to stay away from aluminum in this engine. The shim that I had in there was .6mm, and to land right in the middle of the float range, I wanted a .3mm shim. Since there were no local places that I could think of that might cough up the shim, I attempted to sand my shim down .3mm. All I really did was end up sanding my finger tips off, at which point I gave up and used power tools, effectively ruining the shim. That's fine, McMastercarr has the exact shim I want in a box of 25 at .1mm thickness for only $5. So I can stack a few here and there to get the height correct and be happily riding doubles in no time. Naz also suggested that I remeasure the float after a few miles since the bushing he machined for me might settle in a bit. No problemo!

8 comments:

Ian T said...

i really like this recent frequent update trend.

cuperzacko said...

very nice!

Bruce Cross said...

really nice, Jon. I needed a visual cue on what to do there, and that helped tremendously. thanks!

<3 brownb0x

gnihton said...

mopedjunkyard has them, though I think they might be used. Just went through the tutorial and still don't feel confident enough with my measurements to go ahead with this. if it's off you might have a rear wheel that won't roll backwards, or not symptoms at all and then wham, you shoot a bearing through the case and maybe have to replace your whole top end. $15 bucks and a little piece of mind, though not really!

Evan said...

This is a great post -- it has been very helpful. I was curious as to what shims you got. I'm trying to do the same thing, but cannot find a suitable shim on McMaster (I'm afraid that an ID that is too large will run the risk of being sloppy, and likewise that an OD that is too large will block the oil path to the bearing). Any help would be much appreciated. Also, did you buy shims for the crank on McMaster? I found some for one side, but nothing good for the other side!

Philip Patrie said...

http://www.mcmaster.com/#din-988-shims/=71rwq6

Metric Steel Shim - Din 988, 0.1mm Thick, 16mm Id, 22mm Od

Forest Crimes Unit said...

does a 16mm ID shim really work just fine for a 15mm od clutch bell?

Josh said...

Great Post. Nice work, Sauce Bauce!