So I noticed quite a bit of crankshaft end play in the Briggs, and after disassembling the engine, I found that someone installed a red plastic like washer on the crankshaft to take up the excessive end play. The washer had worn a bit and rounded off the thrust surface on the gear reduction cover. At this point I knew that I had to have the thrust surface milled flat on the cover. My buddy milled .006 off of the thrust surface to true it up. I ordered a new crankshaft and ordered a plain bearing for the magneto side of the engine. I installed the plain bearing, the new crank, and the gear reduction cover without gaskets to check the end play. The end play was just under 1/16" and should be only .002-.008. This was telling me that I would need a shim about 1/16" to take up the end play. I searched high and low on info pertaining to shimming the crankshafts on these engines. Finally I came across a method used by Briggs to recondition bearing covers from way back. I even found the part number for the shim and the two brass pins to retain the shim on the gear reduction housing. I searched and searched, but couldn't find a shim or the pins. I remembered that I had an old Briggs model BR6 from a Bolens Husky Gardner I think. The BR6 has a different gear reduction assembly, but it is all cast iron like on the 23 R6D. I removed the gear reduction assembly from the BR6 and low and behold, there was the thrust washer I needed! I measured the thrust washer thickness and it was .0005 shy of 1/16".
Now I installed the crank and covers with no gaskets and have no end play, and with thin gaskets, I'll be setting the end play at about .004. Restoring this tractor has me jumping hurdles every time I work on it, but I do like the challenge. Here are some pics of the two gear reduction units. The smaller of the two is the one from the BR6 engine. I can't seem to find any info on either of these units regarding part numbers and diagrams. If anyone has a spare gear reduction unit like the larger one, I would be interested in buying it for a spare.
Gard'n Mast'r Jr. 1956 Briggs Model 23 R6D crankshaft end play dilemma.
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