Ironhead Brain Damage Question/transmission

[SHAKY DAVE]

poppin out of 1st gear.i put new shift forks,counter shaft and the mainshaft 1st gear.andrews of coarse.put it cack in and out at least 15 times because ot the ms thrust washer.way too thick.cant get any up here so it was die grind and file time,over and over.put it back together yesterday(down 3 weeks because of rain and snow)still starting to get loosend up but not enuff so its coming out again and thinnin the thrust washer more.cant read a mic so i cant give you how thick it is.workin in the cold is screwin up my hands,haha.BD question is WHICH WAY DOES THE MS FIRST GEAR GO????flat side in or out????in my factory service manual it dont say,factory parts book the picture looks like the concave side gous out?????
thanks from old feeble me hahaha

[Ferrous Head]

Dave, first off I would invest in a set of trust washers. V-Twin have them. The full set is just under $50 but the time they can save you makes it worthwhile.
Filing, grinding or sandpaper is not the way to get thinner washers. You won't get them flat and the time it takes to do this is way out of proportion to the cost of the correct washer.

I put the "grooved" side towards the case half. I actually don't think it matters.

The FSM calls for 4 thou minimum there. I always go wider, I like 8 to 9 on my race engines.

Here's the thing. The housing that holds the trap door bearing has "clearance" with the bearing. That is, the bearing can move in or out in the housing. If you pull the gearbox and remove the clutch gear when you put the bearing/clutch gear back in it might be hard up against the snap ring or bottomed against the door. There is a lot of play there.

The distance between your trap door and the right case half won't change. It will always be what it is. But the distance between the bearing and the right case half can change.

What I'm saying is if you pull the gearbox out and put it back in, the main-shaft thrust washer size won't change. There is, yes, the possibility that the new main-shaft 1st gear is wider. But it's unlikely to be that much wider. If you had 6-8 thou clearance before it's unlikely you have a large interference fit there after changing the gear.

So, before you go too much farther you need to make sure the trap door bearing is fully seated against the snap ring.

Now, there is the possibility of that bearing moving while in service. That is, the bearing could move left or right and close up or increase main-shaft end play. Depending on which clutch style you have it may be more likely to close up or loosen.

But just to start with, go back and check where the tap door bearing is sitting in it's housing.

[Ferrous Head]

These ones.

https://www2.vtwinmfg.com/transmissi...asher-set.html

[needspeed]

Originally Posted by Ferrous Head

..I put the "grooved" side towards the case half. I actually don't think it matters...

It matters if the case has the roll pin that keeps the thrust washer from turning. Its clearance for the pin.

But in Dave's case (pun?) it may not matter because I think the pin was discontinued in 1983. The newer mainshaft washers don't have the tang, though using them should work OK? Or grind the tang off.

Maybe the mainshaft bearing would benefit from some extra oil slung at it from the groove? Maybe? Whatever, the groove side should go toward the case.

[sungod]

[QUOTE=SHAKY DAVE;5979776]
.cant read a mic so i cant give you how thick it is.

You can put the washer on a flat surface and place a feeler gauge next to it or even use small drill bits to get a measurement. Straight edge across the two.

[SHAKY DAVE]

you folks know what happened to me allmost 6 years ago.massive head damage,died 4 times so i ride like a bat out of hell and have allways done my own work.still confused about which way the flat side of the gear goes and yeah my thrust washer has the tang and no there is no pin in the case.tryin to remember but i think the flat part of the gear went twards the 23 goofy bearings.unfortunetly ferrous that part # you posted is for early up to 76 ironheads so i'll have to find the right ones..bad time for me to do this as i lost a good local brother and his old lady the friday before new years day in the lower kern canyon.run coming up to put a wild bill plaque on the bridge at mcnallys up river.thank you folks for helpin the guy that dont usually have to have help

[Ferrous Head]

Sidecar racers are just smart enough to take their brains out and put them in the toolbox for safekeeping before we go out on the track.

I doesn't really natter if the tang is on there or not. (No doubt someone will correct me on that). Only thing I ever worried about was having a tang in the wrong position during the install. If's it's point up and gets mashed between the case and the gear/washer, that's a problem.

The part number for the washers changed in 84, not sure if the early washers fir on 84 and later. I don't play with any of that late model stuff.

I think they added some different thicknesses in 73 (or later ?) just to satisfy the pedantic people who insist on 0.004 with no tolerance.

The quickest way to set the end play is by measuring with no washers in there at all. You can use a dial gauge and magnetic stand on the end of the main shaft (or do it by "feel") Subtract the amount of end play you want (6,8 10 thou) and use the closet washer they make. If you pick 8 thou and think your going to get exactly 8 thou, think again. Never works out just exactly.

The one thing you don't want to do is have no end play. More than the FSM calls for is not a disaster type thing. If you have an engine that's "happy" go and pull/push on the main shaft to get a "feel" for what works. You would be surprised how accurate just doing that can be. You might also be surprised at how "sloppy" 6 thou feels.

[SHAKY DAVE]

what i'm findin i'm needin are the inner and outer bearing washers.got 1 but i musta lost one during the original teardown.guess the lockup was from the spacer with the tang lockin itself to the bearing race.looked on ebay but couldent find any

[SHAKY DAVE]

found 'em.ordered

[Ferrous Head]

Dave, it would be unusual for the MS thrust washer to "lock up" anything. Not saying it can't happen I've seen plenty turned blue and grooved. I think from people setting end float with the bearing in the trap door set wrong.

If things go horribly wrong there the rollers can skid and they can damage the case race. This means honing the race. Only once have I ever had to replace a race.

It really would pay you to check the end float properly at least one time. Dial gauge on the end of the shaft. If it's within limits, push it in and out a number of times and get used to what that feels like. In the future it becomes a quick sanity check.

Now bear with me because I so often get this ass backwards. But early clutches where the push rods run through the MS are pushing the clutch and hence the clutch gear "outwards" towards the snap ring in the trap door. If you install the bearing with it fully seated in the trap door, not against the snap ring, the bearing can move which gives you more clearance.
But in later clutches the clutch gear is pushed inwards. What this means is if the bearing is seated against the snap ring and the bearing moves, it will close up the clearance. That's not good.