Originally Posted by calvin

Sam's right on the relationship between the thrust bearing and the gear's outer rim. I’m lucky in that for whatever reason on my 720 the top of the thrust bearing is slightly above the gear’s outer rim and I'm able to measure the gap with a set of feeler gauges which you can find almost anywhere for a few bucks (only wish that they had a nice slot cut in them so I could slide them all the way in). Mine was one of the original 720s, did Serpent make a design change in their gears or thrust bearings along the way that changed this relationship?

It’s funny that Hudy makes a nice expensive tool that among other things is able to measure the gap using the above “feeler gauge” method. It would work on my 720 but it won’t work on my NT1 because the top of the thrust bearing sits below the gear rim on this car. Unfortunately there is not enough total clearance for me to put a shim under the thrust bearing to raise it up slightly or possibly use another slightly thicker thrust bearing and still achieve my desired clutch gap. I guess I could look into the possibility of modifying the collet to allow the entire clutch assembly to move back slightly thereby creating a slightly wider gap.

The gauge that Sam recommends is nice but is a little steep for my wallet. I wish someone would make a set of reasonably priced attachments that can be used on any dial indicator gauge. There could be an attachment for this use as well as attachments that could be screwed into the glow plug hole to measure piston position and probably a number of other useful attachments that I can’t think of off the top of my head. I have a nice digital dial indicator that I picked up from Harbor Freight for a very good price that is more than adequate for the job. I’ve thought about having some attachments made for myself, but never gotten around to doing it.

I'll have to try DS's method, but at least on the 720 I thought the thrust bearing actually was supported by a rim inside the first gear pinion. I could be wrong or maybe the WC clutch is different than the stock clutch.