I have a '93 Fatboy with close to 97,000 miles. I haven't ridden the bike much the last couple of years due to an oil leak. I've been lazy and haven't addressed the problem since I'm lucky enough to have another bike to ride. Unfortunately, I don't recall which oil is leaking, but I'm pretty sure it's transmission fluid. I started to tear into it this past weekend, and before I did, the primary level looked good, transmission level looked a bit low. I forgot to start-up the bike before checking the engine oil. Looking into the oil tank, I believe the oil drained into the engine past the check valve.
I figure I'll clean it up, replace the major seals and see what happens. As of now, based primarily on information gained on this forum, I'm planning to replace:

• 12053A - starter jackshaft oil seal
• 12052A - inner primary oil seal
• 11165 - quad seal
• 12050 - mainshaft oil seal – left side
• 12035B - mainshaft fifth gear oil seal
• 33334-85 - sprocket spacer
• 11147B - inner primary housing o-ring
• 60539-89A - outer primary gasket
• 9135 - inner primary bearing
• 34091-85A - inner bearing race
• 60678-85 - retaining ring(2)
• C9259 - Shifter Shaft Seal, HD '80-06, dual lip, Cometic #C9259

I thought the race may have walked on the mainshaft, but obviously that hasn't happened. As you can see from the attached pictures, there is oil all over the place.
Any tips, pointers, observations and general information as to this repair is greatly appreciated! My next step is to order the parts from one of the online HD stores.

 

If you haven't do so, get yourself a service manual, it will come in handy.

You are going to need a 1 & 7/8 (I think that's the size) deep socket to remove the transmission output shaft nut. These are LEFT hand threads, so don't make the same mistake I did and try to take it off the normal way.

A new countershaft gear and a trans case later, I've learned my lesson.

 

Thank you, appreciate the reply. I do have the service and parts manual. The pages are well worn and dirty from my oily fingers. I also already own many of the HD specialty tools for both the 5 and 6 speed transmissions. I'm a bit of a tool junky

 

Cylinder base gaskets and rocker-box for starters. At least with all that oil around anything else you decide to disturb will be well lubricated and come apart easily enough! At least that's what I found on my Glide, when it got to a similar condition, way back.

 

Looks like you are on top of it. Please take pics of your work to share. Pics are always helpful.

 

Ordered the various parts I needed from the online HD vendor Boardtracker HD. Some of the parts I wanted to purchase online were only available in a quantity of 5 or 10, so I thought I'd just pick up those parts at the local dealer.
For instance:
quad seal (11165) is only available in a pack of 10 from Boardtracker
jackshaft thrust washer (31430-93) is only available in a pack of 5 from Boardtracker

Also, the sprocket spacer (33334-85) wasn't available at all! It's been discontinued.
I stopped by my local dealer and sure enough, they also told me the sprocket spacer (33334-85) has been discontinued.
The parts guy gave me a list of a couple of dealers that had the sprocket spacer according to his inventory computer screen, but none of the dealers were nearby.
He also mentioned the name of a company called "Vintage Parts", that's been purchasing old HD parts/inventory. Looking on the Internet, I think this company's website is:
http://www.vpartsinc.com/

Anyways, this past week I headed out to the East Coast Rally. This motorcycle rally used to be called East Coast Sturgis. On the ride out to the rally, one of the dealers that supposedly had the sprocket spacer in stock was close to the route I was taking. Stopped in at Schaeffer's HD and sure enough they had the sprocket spacer. They only had one of them and the part's person said it's been on the shelf since 2002!

I've been busy (it's rally season) and I've been waiting on my parts order, so not much work has been done on the Fatboy.

Took off the transmission sprocket today. I removed the lockplate and I didn't even need my sprocket tool to loosen the sprocket nut. I was able to remove the sprocket nut with my fingers!

I'll start cleaning up this oily mess in the next few days.

 

Am I making a mistake here? Instead of wasting my time and money tracking down this sprocket spacer (33334-85), and using my original transmission sprocket, should I have purchased the updated transmission sprocket kit (40210-85D)?

 

Yes, definitely update the pulley, the nut being loose will make it leak though the splines, quad seal not able to do it's job.
The bad part is with sprocket being loose, it probably damaged the main drive gear splines a little, but the good news is that the updated sprocket has a more narrow spacer, and a wider spline area/fit on the pulley, so it will probably be OK.
The big main seal is different too, I think it comes in the update kit.

Tip on tightening the pulley nut, you don't need any holder tool.
with the pulley assembled, and with the belt on, sit on the bike, hold the rear brake, and tighten the nut to 50 ftlbs, now mark the nut and the pulley, use an impact to tighten the nut an additional 45 degrees, check if the lockplate will line up with the holes, may have to bump it to get there, done.

Your shift arm is too far forward, needs to turn up one or two splines

 

I ordered the transmission sprocket kit (#40210-85D). The splines look good, but I'm not sure what a defective/worn out spline looks like. I don't see any obvious signs of wear. I'm not even sure how the sprocket nut loosened up since the lockplate was on the nut.
I did try to shake the pulley before I removed the lockplate and saw no signs of any wobble, but at that time, I hadn't loosen the rear tire so there was tension on the belt.

I did a bit of research on this transmission sprocket kit to understand what's in it and why one would need it.


40210-85D Transmission Sprocket Kit (1340 Big Twin models), Includes seal, spacer, sprocket nut, lockplate, screws
Instruction Sheet: -J00092.pdf, Transmission Sprocket Kit, REV 10-1-94

Each kit contains the following components:
Transmission sprocket (32T) 40250-94C
Transmission sprocket nut 35211-91B
Lockplate 40251-92A
Screw, 1/4-20 x 5/8 knurled socket head, grade 8 (qty: 2) 3594
Spacer sleeve (sprocket spacer) 33344-94
Main drive gear large (outer) oil seal 12067B
Quad seal 11165


With this kit installed, these part numbers will change from the OEM 1993 version
Transmission sprocket (32T) 40250-94C
Spacer sleeve (sprocket spacer) 33334-85 --> 33344-94
Main drive gear large (outer) oil seal 12050 --> 12067B


*** Below information is from the book, 101 Harley-Davidson Performance Projects For Evolution Big Twins And Sportsters ***

Tip: Always update to the latest design pulley (40210-85D)
The updated pulley has more spline area. That, combined with the lockplate and spacer largely solves the leaky, loose pulley syndrome that's plagued too many Big Twin riders.


Front Pulleys
The pulley is dependent on the strength of the splines and the clamp load. Without enough clamping pressure, the splines alone can't take it and wear prematurely. Any noticeable wear on the splines means replacement is adviseable and failure is probably not far off.

Loss of clamp load can also cue the tranny seal to leak for much of the same reason. Insufficient clamp load pressure on the seal (in other words, the pulley's loose) allows oil to sneak right on through it.

To address these issues, H-D extensively redesigned their pulley in late 1993 and introduced it to the production models in 1994. The new pulley (#40210-85D) is available as a kit, including a pulley with 50 percent more spline area and a much heavier duty spacer, along with the different oil seal required and all the related fasteners and hardware.

This design is such an improvement that it's worth doing to older, high-mileage models when the belt is replaced. In fact, immediately is none too soon for any belt-drive Big Twin with the older design pulley - especially heavy bikes, like dressers and Heritages, which have been known to chew up the pulley well before the belt wears out, some in as few as 25,000 to 30,000 miles.

The trick to perfect installation is a light smear of oil on the back (motor) side of the new retaining nut and Locktite 262 (red) to the threads. Then crank the nut on (to your left) to 50 foot-pounds of initial torque. Then, tighten an additional 30 to 40 degrees. Do not, no matter how much you'd like to, exceed 45 degrees. You can figure on 11.25 degrees of rotation per tooth on the new 32-tooth pulley, so mark the nut's initial position against the closest tooth, then "three teeth tighter" for your final position.



Good eye! That shifter arm is shot/worn out. Already have a Baker (3375-85SA-A) Truss Style Shift Lever to install as a replacement.

 

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