I have a 1975 Commando MK III. I seem to have a leak at the front of the transmission. I think it is coming from a large acorn nut reachable from the bottom up. It appears to have a very thin aluminum washer which I think is the source of the leak. I think I have identified the acron nut as holding the detent plunger and spring. If I get a new washer (assuming it is a sealing washer), can I remove the acorn nut, replace the washer and put the acorn nut back on without something coming loose in the trans? It almost seems too easy if that is all it takes to seal the leak, but I have this vision of hearing a clunk inside the tranny when I pull the acorn nut off.

Yes you can pull the detent holder and change the washer. there is of course the spring that will push the "acorn nut" out, but the detent plunger can not go inside the box, and may well fall out also with the spring.

Before you remove the acorn nut/plunger holder I would insure that the assembly is properly torqued, this may fix your leak. On my '75 there was an O ring under the thin washer, an O ring shows on the parts views of some suppliers. RS

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