Transmission/1st&2nd gear problem...what is it?

[uberkafer]

OK, I tried to do a search but it mostly returned people talking about FIXING 1st or 2nd gear without really saying what was wrong.
I plan on going to look at that '79 in the next day or two and I've picked up that there is a possible transmission issue with these old XS's. What, exactly is it? What is the fix? Is it expensive?
Is there a way to tell if the bike I'm going to look at has or had this problem?
Just fact-finding so I make an informed decision....

[madmax-im]

Re: Transmission/1st&2nd gear problem...what is it?

Originally posted by uberkafer
OK, I tried to do a search but it mostly returned people talking about FIXING 1st or 2nd gear without really saying what was wrong.
I plan on going to look at that '79 in the next day or two and I've picked up that there is a possible transmission issue with these old XS's. What, exactly is it? What is the fix? Is it expensive?
Is there a way to tell if the bike I'm going to look at has or had this problem?
Just fact-finding so I make an informed decision....

Hey Scott...to answer your questions as best I can...The 1st/2nd gear problem is when theses gears slip out.The dogs and the slots that engage the gears get worn ..round and thus they are no longer meshing correctly.There are a couple of ways to fix this...1)remove the gears and dremel the slots on the gears so they dont slip out of the dogs(cheapest option) 2)Rather than dremel the gears...do what I did...I bought new factory backcut gears and replace both gearsets(1st/4th and 2nd/5th).These gears ran to abt $400.
There are procedeures on how to do this fix in tech tips.As to what to look for when test riding an XS11.If you are shifting and accelerating thru 1st and 2nd and you are giving it alot of RPMs...if 1st or 2nd slip out under hard accleration then you know it needs this fix HTH... BNE...actually depending upon how bad the tranny is on the bike3 in question...it might slip under "normal"acceleration.

[trbig]

The problem is that the dogs of the gears don't mesh together very far slots they go into to engage the gear. Any rounding on the front edge of these dogs, and under power, it forces the gears apart, then tries to engage the next slot and gets forced apart again. It resembles (To me) like sitting on a machine gun as it does this in rapid succession. Eventually if it keeps doing this, it will do it even at an idle, to where the gear is useless. Many people ride with no first gear for a long time before breaking down to do the fix.

The fix involves a Dremmel tool and some time. It isn't a financial cost really, unless your time is money to you. You simply back-cut the gear dogs and slots to where when you apply pressure, it actually pulls them together instead of pushing them apart. There's also a washer you can move on the back sicde of 2nd gear to nearly double the amount of distance the dog engages the slot there.

Tod

[Ken Talbot]

If the bike has "the problem", the dogs that engage the holes in the gears are worn and rounded at the edges. When you apply power, it tries to push the gears apart. It will slip out of gear under hard acceleration, then back in when you ease up on the throttle. I have not experienced this directly muself, but the effect will be quite noticeable.


Gee, looks like we're all reading this at the same time, and I was the third slowest typer....

[madmax-im]

Hey Tod..
It is my understanding that if you keep the original gears and dremel them..then it would be advantageous to move that washer onto the opp.side of 2nd gear.However if you just go with replacing the old gears with new factory backcut gears...then it isnt necessary to relocate that washer... Just remember to install all the gears so that none of them are backwards DAMHIK!

[ClarkGriswald]

Did ya check the tech tips area? there is some real good writeups and the last one is a description of the trans with pictures of it in different gears.. thats pretty informative..

[uberkafer]

I have now! I promised I searched before posting...guess I just wasn't putting in the right search terms.

[ClarkGriswald]

Have faith! I went from absolutley no knowledge of this particular bike and its particular problems to whippin out the gear fix in a few days.

Knowledge really is power especially if your already a wrencher and just needed the info..

[trbig]

madmax-im,

I disagree with your statement. Buying new gears may fix the problem for now, but the real problem... the fact that the gears don't engage very far.. is really the heart of the matter. New gears AND a washer swap, in my opinion, would be the best option.
Yes, your new gears are back cut somewhat, but they still are only engaging the slots little more than the thickness of that washer they talk of swapping. New gears and the washer move would assure a lifetime fix, since grinding and this move appears to also.


Tod

[uberkafer]

I talked to the seller earlier today. I hope to see the bike tomorrow.
I asked about gear troubles and he said, "No, unless I'm wearing particularly clunky shoes, then I find going from first to second a little notchy sometimes. But NO popping out of gear or grinding".
Is there a certain time or mileage this problem would crop up? I guess it depends on riding/shifting habits, but if it was gonna happen would it be there by 35K?

[ClarkGriswald]

Its totally up to the treatment of the bike over its lifetime. I was told mine skipped 2nd.. but when I tried it at first it wouldnt hold first above much more than idle..

I did the fix. I did not move my washer. Only reason was that although my 2nd gear setup showed that it was skipping.. not only worn but the face of the gear that is the female of the mesh shows mirror shiny areas where they rub, yet my second situation wasnt anywhere near as bad as the wear on the other set of dogs/slots on that shaft.. correct me if I am wrong but I belive that is when the bike is in 3rd gear that those are interacting.. now mine showed no signs of having ever skipped (the shiny face) but the rounding on the dogs/slots was the worst of the 3..

Of course I did them all. My 2nd gear pair was the least worn of the dogs/slots but definatly showed slippage..

Now they all work well I have just over 100 miles on her and it shifts ok, Ive missed fourth a few times.. My clutch cable is old and needs lubed so that kinda messes with ya but its a strong clutch and if ya work it fast and nice it treats you well.

I did not flip my bike over, I just did it there on the center stand. I bet you could get the bike up on the center stand with some kind of blocking (better be solid/safe) under the front tire and center stand and get some more room but I managed to get my meathead under there.. (I had no fear of the dreaded shift forks, NO machine can beat me but I can see why they flip them over.. would be much easier).

[madmax-im]

Originally posted by trbig
madmax-im,

I disagree with your statement. Buying new gears may fix the problem for now, but the real problem... the fact that the gears don't engage very far.. is really the heart of the matter. New gears AND a washer swap, in my opinion, would be the best option.
Yes, your new gears are back cut somewhat, but they still are only engaging the slots little more than the thickness of that washer they talk of swapping. New gears and the washer move would assure a lifetime fix, since grinding and this move appears to also.


Tod

Hmmm...well I dont know this to be a fact but I had heard this from a few ppl...but that was after the fact...I had already replaced my gears and also relocated the washer too... so in any event I should be good for the rest of my life...LOL I'd be curious as to what TC would think abt this....

[bikerphil]

Originally posted by trbig


New gears AND a washer swap, in my opinion, would be the best option.

I totally agree with you on that, Tod. The more contact area on 2nd/5th, the better.

[barberad]

Clark, for some reason your name seems vaguely familiar Anyhow, how long approximatly did it take you to complete, and how much easier and time would you have saved by flipping the bike?
I am trying to build the guts to do this on mine.

[strippedFJ]

Uberkafer, if you don't know already, make sure the gear lever is adjusted correctly for you. A loosely set up gear lever will amplify gearbox wear.