hello, heres some strange stuff i found. i have a 1980 sportster and a tooth broke on third gear, i replaced it by removing the shifting mechanism, then slipping the gear off, then the new one on. then i noticed the mainshaft ball bearing wiggles and seems to be held in with only 1 out of four (stay?) pins (the little rolled pieces of metal that hold the bearing in the mounting plate) and found some pieces of them along with the broken tooth in the case. also the tooth punched a small hole about the diameter of a 22 rimfire bullet through the rear wall of the casing when it broke, i don't see any fracturing, so i am planning to have somebody spot weld it and file it smooth.

1. has anyone encountered this before,
2. whats going on with the pins,
3. could the wiggling mainshaft bearing cause third gear to break?,
4. im thinking of just finding some new stay pins and pressing them in, is that ok?
5. when i took the primary case off, i found out someone had converted it to a belt primary instead of a chain primary, it seems they have rerouted the oil flow to not go through the transmission or primary, and put a nipple fitting and tube to vent, and a bolt to fill the gearcase. being a left foot shifter, theres a large opening where the shifter pedal shaft comes through the transmission mounting plate, can't oil just flow through? what kind and how much gear oil should i fill it with?
5b. is this a common modification?
5c. the last two digits on the transmission mounting plate are 76, is it possible that theres a 1976 transmission in my 1980 sportster, and would that be why theres a belt primary instead of a chain primary?
please give me some direction here i am very confuzzled
what have i gotten myself into ughhhhhh

thank you


the number


the pins


the broken tooth

 

1) Yes, trannys can fail.
2) Need fixing. Shouldn't come out.
3) Wiggling is not good. Any miss-alignment will cause failure.
4) It's you bike. If you're ok with this. Has to be solid.
5) Belt conversions have been done...not so much anymore - no-one makes them anymore. Later IronHeads have wet clutches - yours is dry? The clutch shell has bearings that need lube - how is this achieved? You will need to research what kit you have and how it should be set-up. Most are kits are for wet primaries. Formula plus from HD is the common primary fluid used, there are AM fluids avail also.
5b) not any more - no longer available (you may get lucky on Ebay from time to time)
5c) that is a casing number not manufacturing date. No belt is an AM kit.

 

Some tech links to help you go through it and get it together:

http://xlforum.net/vbportal/forums/s...d.php?t=657134

http://xlforum.net/vbportal/forums/s....php?t=1734747

http://xlforum.net/vbportal/forums/s....php?t=1297584
(full rebuild thread - tranny has a good detailed section that you should read within this thread)


http://xlforum.net/vbportal/forums/s...d.php?t=688853

Just some light reading.

s

 

perfect! i have decided to take the whole transmission apart and completely re-build her, the race for the main shaft bearing is all messed up, probably from lack of lubrication, you rock scottfisher!

 

to me it looks as if the main bearing has pins pressing on it - my guess when you get it apart the bearing is loose in the -76 cover and you will need a new one the bearing and the cover

this if that is the case, it made the main shaft walk around and that is the 3rd gear issue

 

so here i am, years later. i finally got around to accumulating parts to put her back, or as close to stock as possible. i got a rebuilt tranny, and the correct primary equipment to put a chain back in. my new problems:

1, the clutch doesnt want to go on the mainshaft all the way, only about half of the nut is threaded.

2, how can i assure i put the tranny in right? is it easy to screw up or should i be fine with re using the spacing washers from the old one?

sorry, im not to well versed cause im at work and dont have my manuals around.

thank you guys!