I have a 99 Dyna Lowrider that never leaked a drop until I switch to synthetic oil in the transmission and primary (maybe just a coincidence). After several attempts to stop a primary leak, I realized it was coming from the mainshaft. I do not have the special tools, Mainshaft locknut wrench and hd-41184 transmission sprocket tool (I guess it locks down the sprocket….?) to remove the sprocket. My question is, once the sprocket is removed can the seal be replaced from the outside or does the tranny have to come apart. I am unclear about the diagram in the book, it shows an oil seal, fifth gear in front of the sprocket and an oil seal and quad ring behind. The bearing inner race also needs to be replaced. I can probably get the tools for a short time, but as you can tell, I have not had the sprocket off and do not really want to pull the transmission apart. There is also a seal behind the shifter lever, I guess it can be replaced easy enough? Since I have never done this I would welcome any tips or tricks, any thoughts or comments would be greatly appreciated


Thanks Redliner

 

Those seals are replaced from the outside. No need to tear down the tranny. I hope you don't have the same luck I did. My new seal started leaking a week later. I'm trying to remember how I held the sprocket in place. I didn't have the tool. Seems like I just put the bike in 5th gear and had my wife stand on the brake. Just remember that the lock-nut has left hand threads.

I had borrowed the lock-nut socket from a shop but I like what another guy did. He bought the right sized steel socket, cut it in half and welded some pipe between the two pieces. Cost him about $20 for a $100 tool.

 

Thanks zerotread, I'll sleep better tonight and get some seals and tools tomorrow.