4 speed tranny

picwick · #1 03-27-2005, 10:23 AM

hi ! i own a 84 fxwg shovel 4 speed. i have a bad tranny oil leak at the output shaft. do i need to pull tranny apart in order to replace seal? this model has a high lobe that rides in the inner primmary. this happended at the end of last years riding season so i tried to slow it down by slipping 3 o-rings against the seal to slow it down, but ....you guessed. i still have to fix!!

pococj · #2 03-27-2005, 12:02 PM

Have I got a deal for you! I've done this repair quite a few times, or at least enough I wrote this up and saved it to my Tech Tip file. With a little luck you won't need to tear into the tranny.

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. If they're too worn all the rest of this repair won't matter. 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.

If you're really wanting to try something different, machine an o-ring groove on the inner surface of the keyed main drive gear spacer. Install an o-ring, slide the spacer on, and finish the repair as above.

hawk · #3 03-27-2005, 12:15 PM

Skip that is nothing short of genius

Quote:

ORIGINAL: pococj

Have I got a deal for you! I've done this repair quite a few times, or at least enough I wrote this up and saved it to my Tech Tip file. With a little luck you won't need to tear into the tranny.

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. If they're too worn all the rest of this repair won't matter. 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.

If you're really wanting to try something different, machine an o-ring groove on the inner surface of the keyed main drive gear spacer. Install an o-ring, slide the spacer on, and finish the repair as above.

nada1 · #4 03-27-2005, 10:42 PM

Mine was leaking and I put the super nut on the shaft, the one that has the built in seal....stoped leaking for over 12k miles

picwick · #5 04-11-2005, 08:06 PM

thanks for the tips! it seems that i should have my oil leak solved!! not only did i install a double lip seal, i also managed to slip 2 o rings between collar & oil seal.