Finding Neutral while stopped and in gear

Hi, just a few observations, I've torn down my engine after reading this thread and found zero wear in the points that seem to have caused you problems. Have you checked to see if the shift drum needle bearing is installed at the right height ? It seems that many people re-install this flush with the cases when I believe it should be 1.5 to 2 mm high of the cases in the inside. This is what I've found with my engine with zero wear. If it's installed flush, this would result in excess free play (of about 2mm ), the forces on the shift drum when in use would be along the shaft, causing the wear on the inside of the stopper plate and then the neutral plunger would end up about 2mm to one side, just like the picture you have posted. I'm no expert. Is this a possibility or am I miles off target? Cos I would think that with the right sized drift and a hammer you could tap that bearing back into the right clearances from the outside of the engine and removing the problem.

Just a side comment - Recently I noticed that when stationary and trying to get into neutral, but instead just jump back and forward between 1st and 2nd, pushing the bike forward just a couple of inches with my right leg while changing gave neutral quite easily.

rockhead said:

...Is this a possibility or am I miles off target?

Click to expand...

Hey, rockhead, welcome to the thinktank.
Good observation on the shiftdrum's needle bearing. I assume you're only discussing the smaller pressed-in bearing, on the engine left side. On the right side is another, larger, needle bearing, but that didn't exist on the early XSs.

All the shafts that span the XS case are locked into position on only one side.
The crank at its rightside ball bearing,
The mainshaft at its rightside double-row ball bearing (using a "C" retainer),
The countershaft at its leftside drive bearing (using a "C" retainer),
The shiftfork guide bar at its rightside notch (fitted into the shiftdrum's "C" retainer, stopper),
And the shiftdrum at its rightside "C" stopper.

Due to thermal expansion/contraction, the aluminum case width can vary as much as 0.026" (0.65mm), or more. (From here):

http://www.xs650.com/threads/xs650-clutch-pushrod-experiment-tidbits.32267/

The steel shafts don't change as much, so their lateral positions can only be established on one side. Their opposite ends must be allowed to float in/out.

As such, with the shiftdrum's lateral position established by its "C" stopper, there needs to be a bit of gap between the other end of the shiftdrum and the side of its roller bearing, as seen here:

(Pic excerpt courtesy of member Meddy)

Paul Sutton said:

... I noticed that when stationary and trying to get into neutral, but instead just jump back and forward between 1st and 2nd, pushing the bike forward just a couple of inches with my right leg while changing gave neutral quite easily.

Click to expand...

Hey, Paul! Now, that's significant, and adds to my suspicions about the sliding forces in the shifting components. I've thought about doing the same, noting any differences, just kept forgetting.

Let's revisit the 1st-to-neutral action.

The 4th slider, its dogs engaged into the 1st wheel's slots, needs to be pulled out.


That is accomplished by the rightmost shiftfork.


That shiftfork's 2 finger-pads ride in the 4th slider's groove. If those 2 fingers aren't applying equal pressure, the 4th slider could 'cock' on the countershaft, and bind, resisting further movement.

By rolling a short distance while still in gear, the countershaft will rotate, the 4th slider will also rotate, and its 'cocked' angle would be changed by its new relationship to the shiftfork fingers, possibly unjaming it, allowing it to continue its withdrawal from the 1st slots.

This 1st shiftfork shows a catastrophic condition on the insertion side of one of its fingers, the one closest to the guidebar, and the one that would be deflected less than the other finger, if the shiftfork unit was allowed to tilt on the guidebar.


The 2 fingers need to contact simultaneously, in parallel with the 4th's groove, to properly shove the sliding gear, otherwise there's the chance of the slider 'cocking' on its shaft, leading to jamming. Maybe that's one of the reasons mamayama changed the spline polishing in '77.

But, to take this further, while sitting in 1st gear, the clutch drag is applying some degree of torque to the 1st wheel gear, thru the 4th's dogs, to the 4th's engagement to the countershaft splines, on the drive-sides of the splines, which have no callout for polishing. Add to that the potential for spline drive-side surface distortion from years of doing the 1st gear *clunk* entry, and you now have a roughened surface that adds to the difficulty of withdrawing that 4th slider. And, add to that the potential surface damage on the thrust-side faces of the dogs and slots, caused again by that 1st gear *clunk*, possibly hammering pieces of dirty oil grit into those flat surfaces.

This all really needs a chalkboard, with plenty of room for arm waving.

I've also seen pics of guidebars, showing strange wear/gouge marks where a shiftfork attempts to 'cock' during its lateral travel. Need to start collecting those pics.

Edit: Here's one:


If you do a side-end-on view of the transmission, noting the locations of the shafts, guidebar, and the shiftforks' pins (where they engage the shiftdrum's slots), you'll notice that the center shiftfork forces are in-line, but the outside 2 shiftforks' forces are cockeyed.


Operating under a history of a reasonably sane, mild-mannered rider, this wierd tranny layout seems to work fine, not demonstrating the "find neutral" syndrome.

Put an aggressive/neglective rider in that operational history chain, and I can see the beginning of, and worsening of, shift mechanism wear. And, those wear indicators would be easily overlooked at teardown.

There. That's my ramble-think on this issue. Still collecting data and pics in preparation for my teardown. And, contemplating subtle mods to counteract this syndrome, like making an improved/stiffer guidebar, extending and fit-lapping the shiftforks' guidebar holes, shiftfork alignment jig, bla, bla, bla...

Thanks for the explanation. Much appreciated

Hay 2M.... how about confine the oil in the tranny... you know.... plug the holes so it's a stand alone oil sump...and then put in some real slick oil like STP and full synthetic oil ???? you'ed need to make a way to check the level in the trans and of course drain hole too.... but I think that would go a very long way at solving most of the transmition problems in this o'l girl...... the oil just ain't slick enough and if you put in slick oil the wet clutch can't handle it , soo.... block off the transmission and do it anyway !...... what do you think of that idea ?????
....Bob............

Far too much work, Bob.
You'd need to seal-off the kickstart, elect start, double-row bearing.
Then, block-off engine oiling to the trans area, provide independant oilpump.
And, add another oil fill hole somewhere.
You've also isolated a significant amount of case volume, and the crankcase venting system may not like that...

Ahhh yah I forgot about the shafts going through.... that's what I get for thinking at 5 am and no sleep ! LOL
Thanks 2M way too much work I agree.....
Bob......

Paul Sutton said:

Just a side comment - Recently I noticed that when stationary and trying to get into neutral, but instead just jump back and forward between 1st and 2nd, pushing the bike forward just a couple of inches with my right leg while changing gave neutral quite easily.

Click to expand...

Now that rings a bell.
Some bike of mine in the past had exactly that foible when it was really hot in traffic. I'd forgotten about that, and how I'd noticed it.
I never did anything to 'cure' it, as it wasn't really that big a deal most of the time.
Now that you've jogged my memory, I must try it on the XJ9, as it does this when hot and maneouvering back and forward in the garage.

Grimly, on my XS the problem is worse when the bike is very hot also. I can be riding on a cool day with no problems at all. Then I go into the town and hit the traffic lights and traffic jams and then the problem starts. It is probably in part due to high temperature giving maximum expansion in the clutch push rod department so that I am not really disengaging the clutch quite enough. Next time this happens I will stop and take up a bit of the slack in the clutch cable and see if the problem is cured.

If neutral is hard to find at a stop, shift to 2nd, then position your foot above and lightly kick, tap the shifter down. I'll often use my heel to do this. Pressing slowly won't do it, it's the tap that gets r done. Harder to explain than do but this will get you neutral on just about any bike. (Except Kaws with the second gear at a stop lockout) and that's why they have it, so you can just whack the shifter up to get neutral cause it can't go to second.

It's all in the toe.

I agree with Gary in that you have allot better luck trying a short jab than pressing it with your toe...
on any bike if I was having trouble finding neutral that is what I'ed do....usually it works...
or the rolling forward while tapping the shift lever..... I found early on that trying to Press the shift lever simply makes you over shoot neutral and go right into 2nd.... all my Honda's were like that....
....
Bob......

Update.

Over the last 4-6 weeks of riding, my shifting has been getting clunkier, and "finding neutral" has gotten progressively worse. Last week, setting still in traffic, idling, clutch pulled, in 1st, the shifter wouldn't budge at all. In fact, the bike was trying to creep forward. Had to hold it with the brake. Severe clutch drag.

Revving the engine didn't help. Let the clutch out a bit, to see if my engagement point moved. I have it set to engage when the clutch lever is about 2/3 released, about 1/3 from fully released. Engagement point was the same, and there was no change in the amount of drag between fully pulled and the engagement point.

There's 5qts oil in the thing, overfill for the front-wheel-hitch project. So, the clutch is getting plenty of oil.

I'm still running the experimental clutch, so I know the plates are actually separating.

http://www.xs650.com/threads/yamaha-xs650-experimental-clutch.47498/
http://www.xs650.com/threads/yamaha-xs650-experimental-clutch-version-2-0.50189/

Could it have broke?

Well, it's due for the 1,000 mile oil change. Couple of days ago, dumped 5qts of old oil, refilled with 3qts of fresh oil. Replaced my BOF (side filter paper sleeve).

Whut the........

Instantly, and after about 100 miles of riding today, I have my easy shifting, neutral finding back!

Son-of-a-gun.

It was the oil!

Old or too much?

Old oil. I'm kinda guessing here, but it seems that the first 700 miles on the oil was ok. During the last approx 300 miles is when the system degraded. About the same time frame that temps out here got into the 90's, and my sump temps got to 230+°F.

What's in that stuff. Was using Valvoline conventional, motorcycle 20w50, JASO certified. Now running Valvoline VR. We'll see how this goes. Maybe next oil change will try Mobile 1 20w50...

I discovered that good oil like Valvoline 20w40 it only good oil for about 2000 miles in a bike..... it simply looses it's stickyness
and does so in a very short time.... I guess the higher temperatures of the motorcycle engine as compared to a car just burn up
the goodies in the oil.... so multi-grade becomes one grade at that point.... which invariably thins out to be something like 10w oil
I ran the same oil in my Honda 700 shadow for a long time and decided one day to check it.... it never used any oil at all... but it was fairly black
to my shame..... but upon draining it I noticed it was extremely thin oil..... and that alerted me to how multi-grade oils work
they have a chemical in them to thicken up the oil as the temperature rises..... after a while that chemical wears out or dies and your left with the base oil, which is supposedly 20w on 20w40 multi-grade.....
I went to my truck and got 4 quarts of straight 40w valvoline and filled the bike with that..... it ran much quieter and better than it had before
and I ran that oil for at least 2 years .. with no ill effects running back and forth between shingle town and the Ranch near Redding Ca.
a good 80 miles 1 way.... never had a bit of problem with the engine..... the ignition switch almost killed me but that's beside the point !
No...I do not like Multi-grade oils ! I have it in my XS650 now because I could not find straight 40w Valvoline they had 30w but I wanted it thicker sense the big twin runs fairly warm....
this may sound like a stupid thing to do to some.... but what ever... it's what I do and I've had no engine ware problems in my car,truck or bike
I go with single grade oil if I can get it !
....
Bob......

Well - glad to hear that it is sorted out 2M and a great new piece of knowledge to add to the storehouse from which we all benefit!

I must say - 5 quarts in a 2500 cc crankcase.....has always surprised me that it worked OK and didn't puke oil all over the southern end of Texas.

P

I have switched to 15w40 Rotella dinosaur with my last oil change. It is Walmart cheap and works just as well as the full synthetics.

This oil story is quite interesting. Like Bob Kelly III said it is better to run a straight-grade than a multi-grade if temperatures permit. The straight grades use two naming systems: example SAE 20W is a winter designation and SAE 20 is a summer designation.

My question is for warmer climates, should the straight-grade choice then be a SAE 50 if available? I believe that a SAE 50W if it exists will be too low in viscosity as its characteristic relate to low temperature operation. Also bear in mind that beyond 100 Celsius the SAE 50 will be lower in viscosity than a multi-grade 20W-50. This is because the added polymer not only reduces viscosity at low temperature but also suppresses thinning at high temperature.

Bit of a complex situation - Perhaps the best practice is to just stick with the recommended multi-grade and change the oil at 1000 miles??? But changing at 1000 miles becomes expensive if riding a lot. I just checked and I only changed the oil a couple of rides back and I have already reached 600 miles.

Maybe a straight-grade and a proper paper oil filter is the way to go for minimizing oil cost???