Im sorry, I jumped the gun! Im all on with the shaft coupling; DUH! You might have to struggle to get at the trans coupling nut. After you replace the seal, make sure you put some sealant of your choice on the trans spline as well. Theyll leak through that too. I had Kalamazoo Gear do mine and it was completely apart within 30 minutes. If youre up to making your own, buy a correct sized socket off ebay, cut it down and grind or machine 4 slots for some key stock and weld them in. 0407190 is the socket number from Allison. You might get lucky.
Thanks, I've been talking to Brian at Acadian and he has been really helpful. Waiting on a drawing for the spanner socket and spanner nut for the "M20" (I believe it is different than the "MH20" one that you have.) I'll probably have to machine one of these out of a socket - I just don't have any dimensions to work off of yet, and I'd really like to have that tool when I head to the boat in a week and a half.
I have the seal already and will have a pile of 518 flange sealant for the splines, as per Brian's recommendation.
It's all about acquiring or fabricating a spanner socket at this point, and I haven't been "lucky" with that so far. There is no part number in the manual, it actually says "fabricate locally" and offers a drawing with no dimensions that has "FABRICATE" as the model number.
For what it is worth, the MH and M series do use different Output Flange Nuts. The MH nut is model number 6771999, and the M is model 6700015. I can't assume they use the same tool because I know nothing about the nuts, but maybe they do.
The M series nut uses a cotter pin through a hole in it to secure it, and the MH has a staking flange with no cotter pin. (I had to look up what "staking" was...)
I do have the service and parts manuals for these, they aren't helping me figure out how to build quite an important tool that is required.
