Im helping a friend fix his 77 FL that he bought. Its got what looks like an early 80s trans with a belt drive primary. He thought the main seal was leaking but when I got into it that seal looks fine. So does the one between the counter shaft and main shaft. I pulled the main seal out and there is a flanged spacer that the seal actually rides on. The counter shaft is splined so there is no way the spacer will seal on the shaft and thats where the oil is leaking. Somebody said there should be an oring behind the spacer but i dont see it in the parts manual. They also said you have to RTV the spacer to the counter shaft and fill in the splines. It doesnt look like there is room for an oring and it will probably just get torn up being pinched between the bearing and spacer. Any thoughts? Heres some pics.

 

This following applied to my chain-driven, but the principle is the same.



Here's what I did to my old '78 FLH many moons ago. As long as I kept the sprocket nut tightened it would not leak.
First, your main drive gear and bearing(s) must be in good shape. Get a new cork gasket, a new keyed main drive gear spacer (some of 'em came without a key slot and key, as mine did originally), a double lip main drive gear oil seal, a new sprocket, and a new sprocket nut with a seal on the inner surface and an O-ring type of seal on the backside. Check the surface where your new double lip seal will mate with the tranny case. If it has any burrs, scratches, etc., you'll never get a seal for any length of time.
Start the assembly process by almost filling the cavity where the cork seal goes with a non-hardening gasket compound (I've also used hi temp grease), leaving just enough room for the spacer and double lip seal to fit in the cavity properly.
As long as I put everything together this way my 78 FLH NEVER leaked. Keeping the sprocket tight is mandatory. Can't count the number of times I tore into a BT tranny and found the sprocket nut loose; it was an almost always thing.

 

I'm seeing a mix match in parts there between a few different years trans . That's a maytag 79 and later trans but the sprocket spacer you had in hand is pre 77 . The 4th or output shaft gear the spacer rides on is the same size all year 4 speeds so no change there . I'd get a parts catalog and find the later model parts like that spacer , they had a much larger shoulder/sealing area on them and the correct seal for it .

 

yeah the bike is a 77 but the trans is like an 80 or 81. They probably used the spacer from the original trans. So after I get the correct spacer what will keep it from leaking? Cause there is nothing behind the spacer but the bearing and the splines on the counter shaft are wide open. Somebody had originally just packed the splines with RTV but the gear oil made quick work of disinigrating that.

 

Grab the splined shaft and see if you get any up & down movement on the mainshaft it rides on , if so the bushing is shot and needs replacing or it will leak again .

 

im looking at the HD parts manual. it shows 4 different spacers: 77-79, 80&81, 82 FXB, 82 and up FXS. It doesnt show an oring behind the spacer (J&P cycles catalog shows it). The cork washer is shown for 71 to 77. The owner claims all they did was throw the trans in..they never had the seal out. So its not the spacer from the 77. When I pulled it apart it looked just like the pictures.......seal, spacer and thats it.

 

I think I got it fixed. I slipped a 1/16" o'ring behind the spacer. Seems to have worked.

 

Make sure you get the sprocket tightened down good , o-ring can hold it out a bit till it eats itself then you have a loose sprocket .

 

I impacted it on. So it should be good. Hes going to have me tear into it this winter and do the bushing cause there was some play in it. Hes rebuilding everything but just wanted it to stop leaking for now. Took it for a spin when i was done..........what a fricken tank! That thing did not like turning. Straight line was nice and smooth but you had to truck drive that baby thru the corners. Oh and im spoiled with my EFI Road King..........kicking this thing wore me OUT. I weight 213 lbs and I had to put every damn pound in it! Fun though....just cant get that sound from an Twinky.

 

this is why i love this forum, the most random issue and there will always be someone who can give you helpful insight. kudos to you boys who know shovels!