FXR primary drive seal ???

[Hawkeye]

Yep me again


I have a 92 FXR though it's a made up bike as it has a 5 speed box that has a tapered drive shaft from the gearbox that the clutch is mounted on. I know it should be a splined shaft for this year.

What i want to know is, is there a seal at the back of the primary drive rear casing behind the clutch. My spare catalouge does not show one.

I have developed a leak but cannot see where it is coming from, the leak is very small but annoying. I cant see where else it would come from.The started motor has been removed recently but the what no seal there.
I can see fresh oil running down the back ot the primary case after a run but it is such a small leak.

[Phil]

There should be a seal behind the primary for both the mainshaft & starter shaft.

You may just have an early mainshaft in a later trans.

Can you post pics of both sides of the bike framing the primary/gearbox area in both.

If I can see the problem, I can give you some part numbers.

[Hawkeye]

i will take some tomorrow Phil

[Hawkeye]

David Bailey i anit, hope these are ok.


http://i618.photobucket.com/albums/t...8/IMG_0048.jpg

http://i618.photobucket.com/albums/t...8/IMG_0049.jpg

[ACE]

I believe it used to be known a the 5th gear oil seal failure, The way to get rid of the leak was to put your bike stand on the other side of the bike.

Seriously it is only a silly little O ring type of seal but a major stripdown to get to it. Don't try and live with it, as gearbox oil and drivebelts are not a good mix. I squeezed two seals back in when I replaced mine and had no more trouble.

A tight drive belt will cause failure as will giving the bike some stick over bumpy ground.

[Hawkeye]

Have had the rear wheel out and there is oil at the back of the primary case but not on the belt or pulley. The oil does not smell like gearbox oil either.

[Phil]

Little bit of a hybrid there, with an early style starter & solenoid.

There is a seal that the starter shaft passes through in the inner primary. Part number: 12051. The solenoid should be sealed by an `o` ring, 27060-55.

The seal where the main shaft passes through the primary is a 12052A.

If the oil is coming from the gearbox there are a couple of culprits, let me know.

[Hawkeye]

Thanks for the info Phil. Just had a new started clutch fitted and the leak appeared right after.

This seal is it fitted from the inside of the primary or can you get to it from the back


Ok so i didnt read it all, just seen the inner primary bit

[Ex3t3r]

Originally Posted by Phil

Little bit of a hybrid there, with an early style starter & solenoid.

There is a seal that the starter shaft passes through in the inner primary. Part number: 12051. The solenoid should be sealed by an `o` ring, 27060-55.

The seal where the main shaft passes through the primary is a 12052A.

If the oil is coming from the gearbox there are a couple of culprits, let me know.

Sorry to hijack Hawkeye's post, but Phil you mention that their are a 'couple of culprits'.

Reason why I ask is, I have a 91 FLHS with a leaking tranny and i'm sure the cause is the quad seal
behind the front pulley wheel spacer even though the tranny has been stripped vapour blasted and
re-assembled with a new main shaft bearing and all new seals and given a clean bill of health
by a well respected indie mechanic, yet after 800 - 1,000 miles the tranny leak has reappeared.


So any tips Phil or pointers would be very appreciated.

[kiwidave]

I found this information in my massive Word document of tech tips. NOT MY KNOWLEDGE...but good info from someone in the know several years back.......


all Big Twins including the FXR received a much needed redesign improvement in 1991 regarding the transmission pulley hold down for the pulley nut. The rear belt front pulley slides over a splined appendage, which is part of and an extension of the fifth transmission gear. The gear is inside the transmission with the other gears. The extension goes through the casing, supported by a strong ball bearing. The pulley rotates with the fifth gear. The pulley was initially held onto the splined appendage by a thin transmission nut. In fact the nut was the same one used forever on 4 and 5 speed transmission chain sprockets. On the 4 speed chain sprockets the nut was locked in place by a very effective lock tab that had indents on it to match all of the six 4 speed 4th gear appendage indents.With the 5 speed chain sprockets and pulleys, the shaft is finely splined, (33 splines compared to 6 indents on the 4 speed and some very early 5 speeds), which makes it impossible to match indents on a lock tab with those on the appendage. Harley used a screw to lock the 5 speed sprockets and pulleys. A threaded hole was provided in the sprocket/pulley. A too small allen head, (8-24 3/8" long), screw is inserted to lock the nut in place. The six sided nut requires red loctite to be applied before tightening and installing the similarly locktited screw. Now for the problem. This system works fine on the 5-speed chain sprocket but not on the pulley.First of all, the pulley is too heavy for this little screw and thin, (3/16" thick), hold down nut. Secondly, the screw does NOT lock the nut in place. If the nut comes loose because of the heavy pulley, it is allowed to vacillate back and forth within the parameters allowed by the hold down screw. It can't move very far but it can move. Two corners of the nut stops against the screw either way it wishes to turn since they effectively stick out further. The little movement wears against the nut until it shears. The screw may also come loose on its own, fall out and eventually let the nut come undone and fall away. Thirdly, the skinny nut may lose its threads via stripping and simply fall off.
The Pulley Destroyer
Whichever way the nut comes off, the end result is the same for the pulley. The pulley can now travel back and forth on the 5th gear splines. It can't fall off since it runs into the backside of the inner primary but the splines will wear rapidly necessitating a more expensive repair. How can you tell if the nut has backed off? Well, there will be a puddle of transmission fluid under the bike. Look beneath the pulley at the rear inside of the primary casings. Why? The pulley moves out along the splines, which allows the pulley spacer to move out also. The spacer also acts as the inner race for the transmission oil seal allowing fluid to flow out and onto the ground. This can also happen while riding and therefore not be noticed as easily. However the symptoms leading to this conclusion are easy to discern. Low or no transmission fluid levels combined with a splattering of oil from the primary back on the bike's left side are the two clues to this common malaise. There is no discernible noise associated with this problem. In 1991, HD introduced a lockplate that fits right over the transmission nut to prevent any movement. A new nut was also brought in at almost twice the thickness of the old one. And the allen screw was increased in size and quantity. Two screws, (1/4-20 5/8" long), are used to hold the plate down on opposite sides.
A Better Quality Pulley
If you own a 1986 to 1993 Big Twin and need to replace a worn transmission pulley a nifty design change was instituted in 1994. These 33 splines have a bad habit of prematurely wearing out on the earlier models because there is not enough interactive mating surface area. In 1994 Harley doubled this area on the their pulleys. You can retrofit a 1994 and later stock 32 tooth H.D. pulley onto your 1986 to 1993 Big Twin. Not only that but the later style locking ring mechanism to prevent the pulley nut from coming loose is also supplied along with a new oil seal.