Board index Flathead Power-Technical Questions, Answers, and Suggestions Servi-Cars Starter Ring Gear

Starter Ring Gear

Post Fri Sep 18, 2015 12:47 pm

Posts: 2
Has anyone had any experience installing a electric start ring gear onto a earlier 41-up solo clutch basket. What's the best way to remove and install rivets as well as the offset created by the thickness of the ring gear which is around 5/32" Do you machine the amount equal to the thickness of the ring gear off the clutch sprocket. Thanks

Post Fri Sep 18, 2015 2:28 pm
Pa Site Admin

Posts: 5837
Location: Ohio USA

sidevalvebob wrote:
Has anyone had any experience installing a electric start ring gear onto a earlier 41-up solo clutch basket. What's the best way to remove and install rivets as well as the offset created by the thickness of the ring gear which is around 5/32" Do you machine the amount equal to the thickness of the ring gear off the clutch sprocket. Thanks


First you have to drill the 10 rivets holding the clutch basket to the sprocket gear/bearing race assembly out. A good drill press is necessary. You will need several 3/16" diameter drill bits on hand to accomplish that task. The rivets need to be drilled out from the backside of the clutch basket. I center punch all 10 rivets as close to their centers as possible before I attempt drilling them out. This is where the additional 3/16" diameter drill bits come into play. If you don't nail dead center on the rivets when you center punch them, the drill bit will scrape the wall of the hole the rivet is peened in. The sprocket material is hardened clear through. In other words, the whole sprocket/bearing race assembly is super hardened. All surfaces are as hard as the bearing race itself. It can be cut with a tool though. That is our next procedure. After you have successfully removed all 10 rivets, you have to separate the tin clutch basket from the sprocket gear/race assembly. Make certain there is no rivet material left in the 10 holes. Now you need a very powerful lathe. The lathe is needed to do the stock removal necessary to accompany a ring gear, as you noted. I recommend having a ring gear on hand before doing any machining of the sprocket assembly. Not all ring gear thicknesses are identical. The procedure is to chuck the sprocket/bearing race assembly up in the lathe using soft jaws and a four jaw chuck. Indicate the complete assembly in to zero using and indicator on the bearing race and the clutch basket register. Now here comes the hard part...any more rpm than 60, and any feed rate more than .0015" per revolution, and any cut deeper than .015" per pass, will destroy your tooling. Tooling is Carbide. You are going to spend a lot of time taking many small passes on the bosses of the lugs of the sprocket/ bearing race assembly. Face off the sprocket/bearing race bosses to the thickness of the starter ring gear. I've done it many times but it takes a lot of time and tooling. Once you have accomplished those tasks, you have to reassemble everything. Ring gear goes on with dish side of ring gear facing up. Line up all three clutch components. 1 the sprocket/bearing assembly, 2 the ring gear, three the clutch basket. Install all 10 rivets from the backside. Support all 10 rivet heads. Peen all 10 rivets from the clutch basket side. Chuck the completed assembly back up in the 4 jaw lathe. Indicate as mentioned before, and skin cut of the excess peened rivet material on the face of the clutch basket. You can cut into the actual clutch basket up to .030" to obtain total cleanup.

Post Fri Sep 18, 2015 3:00 pm

Posts: 2
Pa:
Thank you so much for sharing your knowledge I can now avoid the many pitfalls you mentioned. I had no idea that the sprocket race assembly was hardened to such a degree. I think I will now do a couple up and keep one for a spare. Once again Thank You.

Post Fri Sep 18, 2015 3:36 pm
Pa Site Admin

Posts: 5837
Location: Ohio USA

You are quite welcome. The task can be accomplished but it takes a lot of time and effort.


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