5th gear star washer source

[3Phase]

Let me understand, what you're saying is making a thicker washer for the SHIFT PAWL PIN to hit/stop against?

Yes that sounds good, the only problem I see which is easily checked, is if the shift pawl pins (circled in red on my photo) that hit the little shift drum pins have to hit them in a tangent direction, in other words at 90 degrees to the radius. (if that makes sense). If I understand correctly, a thick washer would be hit by the shift pawl pins in a straight line with the radius, which may cause problems.

No. The shift pawl pins and the shift pawl pin bosses should never, ever, hit the starfish washer or the shift drum pins during any shift, up or down.

The Stainless Steel washer I used is just a hardware store SS washer. It has some 'spring' to it like the original washer so it won't just bend like a regular washer and it'll hold the pins in their holes. That particular washer I used happens to be 0.051" thick, 0.012" thicker than the 0.039" OEM special washer but the point is that it's only eighty-five cents, not eleven dollars US or tuppence in UK real money.

I don't see why you couldn't make a better version of the A washer, only with more "feet" on it to do the same job as the two long pins, and grind down the longer pins.

The shift drum pins are all the same length. There is a reason that Yamaha drilled shallow holes for two of the pins but I've forgotten what it is. If you wanted, you could just weld or glue all of the pins in place and never, ever, worry about the special washer ever again but where's the fun in that?

My personal view is - what Yamaha made works well, the stops, how the shift pawl pins engage, the only problem I see is the star washer breaking, and the simple repair I and a few others have done works. Fix the part that's broke, not the bit that works. However, I also like modding so have a go and let us know how you get on.

That's why I replaced the special washer that is No Longer Available with an inexpensive washer that you can probably find along the side of the road while you're pushing your busted XS1100 that won't shift to the hardware store to buy a washer.

[3Phase]

The 'legs' have to be there on the starfish washer or its replacement.

The shift pawl pins do move between the 'legs' during the up/down shift indexing.

Some of the causes of the broken starfish washer:

Upshifting without the clutch or just fast upshifting.

The shift drum tries to slide out of the case to the left as it rotates and positions the shift forks during upshifts. The lateral movement's not bad during a "normal" upshift when the gears aren't under load. When they're loaded, the shift drum has to force the shift forks to move gears on the transmission abacus/Main Axle Assesmbly (Input Shaft)/Drive Axle (Output Shaft). If the whole shift drum assembly is in good shape and it just pushed out to far during one really 'hard' upshift, that's when you can replace the washer and it won't just break the next time you go riding. If the drum assembly's worn, it'll keep moving out of the case and the shift pawl will slice the legs off the starfish like a sushi chef.


What wears?

The left-hand shift drum bearing race wears and can't hold the shift drum.

The shift drum retaining dowel pin can be worn or bent.

Bent or worn shift forks, they make the shift drum work harder to shift gears.

The shift fork shaft/oil pump drive gear shaft can be bent. The oil pump gear retaining clip can be worn or taking a time out in the oil pan because it was installed backwards, bevel side out, on the shift fork shaft.

When the shift pawl wears out, it won't sit up straight on its seat when you shift and it snags the starfish washer, usually during the 4th-to-5th gear upshift. That can leave the bike stuck in 5th gear because if you're traveling, it might be a while before you think about downshifting and the 4th gear shift drum pin will eventually take a swan dive out of the drum and join that oil pump drive gear retaining clip for a swim in the oil pan.

[TomB]

Let me understand, what you're saying is making a thicker washer for the SHIFT PAWL PIN to hit/stop against?

Yes that sounds good, the only problem I see which is easily checked, is if the shift pawl pins (circled in red on my photo) that hit the little shift drum pins have to hit them in a tangent direction, in other words at 90 degrees to the radius. (if that makes sense). If I understand correctly, a thick washer would be hit by the shift pawl pins in a straight line with the radius, which may cause problems.

I don't see why you couldn't make a better version of the A washer, only with more "feet" on it to do the same job as the two long pins, and grind down the longer pins.

My personal view is - what Yamaha made works well, the stops, how the shift pawl pins engage, the only problem I see is the star washer breaking, and the simple repair I and a few others have done works. Fix the part that's broke, not the bit that works. However, I also like modding so have a go and let us know how you get on.

[TopCatGr58]

Further thoughts/discussion

Hey Scott and TomB,

Wanted to discuss this a little further. Okay, the shift boss pins hit the shift drum/washer/pins apparently on the high side or portion that's protruding outward from the center of the shift drum face, hence the propensity for the pins to snag the star washer/plate tangs over the pins and occasionally bend them backwards. I see that there are recesses cut into both the star washer as well as the "A" washer, and was wondering if the pawl boss pins would actually move further down into those slots while the drum is rotating/shifting, and then the protruberances would actually act like bumpers kicking/pushing the shift boss back away from the drum to help in resetting the pawl? However, looking at mine, as well as your photos, I can't see any signs of impact wear in the slots, nor on the sides of the protrusions to indicate that the shift pawl boss pins make contact there??

Thinking that the shift pawl boss pins are there to just prevent the shift pawl from moving too far so that it would only move enough to shift one gears worth of drum rotation, and therefore NOT overshoot/rotate the drum into shifting 2 gears up/down by mistake.

IF that's the case, then the recesses around the starplate washer/A washer are relatively MOOT, and as long as you had a thick enough washer that was just that diameter to cover the pins and simulate the same position/depth of the pins/A washer, then using a thick enough piece of plate steel cut to the proper diameter, and then drilled with the mounting holes would be adequate to replace ALL of those Star/A washer parts, and keep the pins in place(grinding down the 2 extra long ones, so that the washer was just FLAT, no fancy bending/trimming required.

Any more thoughts on this?

I'll eventually be getting back into Godzilla to repair my 1st/2nd gears AGAIN, and while I'm there, I may even look at replacing my OEM star washer plate to prevent any future possible failures of this part, and am just thinking of the EASIEST way to do it.

T.C.

[3Phase]

That was fun!

XS1100 Shift Drum with old and new washers


New Stainless Steel washers with old washers


Checking the new washers for fit


New 1.32mm (0.051") x 1/4" x 1 1/2" Stainless Steel washer


Old 1mm (0.039") thickness star washer aka Plate, Side 1


Scrap aluminum template for the Stainless Steel washer


Scrap aluminum template pinned and cut


Side: Stainless Steel washer is drilled, pinned and formed


Top: Stainless Steel washer is drilled, pinned and formed



The washer still has to be notched for the shift pawl pins and the 2nd gear index alignment mark has to be scribed on it but with a little work a 85 cent Stainless Steel washer replaced the broken, obsolete, $11 part.

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[3Phase]

The 85 cent star washer fix works!

It works.

I haven't cut the notch in the washer for the shift pin index function but I just finished -- mostly -- setting up the shift drum with a 85 cent 1/4" x 1 1/2" x 0.052" SS washer.

The original starfish washer is 0.039" (1mm) so there is only a 0.013" (0.33mm) difference.

I'm pretty sure I can clean up the shift pawl and the shift pin boss to get an extra 0.015" or 0.020" clearance without grinding the pins.

I don't have pictures ready yet, the phone-to-computer cord broke so I have to find the memory card USB adapter and I have to mow the lawn before it gets dark or I sleep out on the curb tonight. I'll give y'all three guesses which one's getting done right now and the first three don't count!

BBIAB

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[TopCatGr58]

It still amazes me the trouble Yamaha went thru just to be able to use all of the dowel pins of the same length!?

1) They had to vary the depth that the dowel holes were machined/drilled in the end of the shift drum.

2) They had to machine the "A" shaped crow's foot with just 2 shift stops.
3) They then had to engineer, cut and press/shape the fancy star washer.
4) Then they also had to cut/press/shape the locking washer.

It's NOW obvious to me that the prongs on the star washer get bent when the shift pawl stops hit the washer too hard and catch on JUST the star washer lip/edge and not the washer/dowel pin combo. Then once the prong is bent back, there's nothing to hold the dowel pin in, and so both vibration and shift pawl contact causes it to eventually fall out. The Star Plate Prong is not stressed by the dowel pins pushing against it at all really!

SO....either getting a fairly thick washer and cutting it to shape with the ears/prongs and such to replace both the "A" crow's foot piece as well as the star plate.....OR also use a piece of thick aluminum plate and machine the prongs for the pawl stops into it, along with the alignment dowel holes center mounting bolt hole, and then just use either a lock washer or even just some LOCKTITE vs. some fancy Z shaped locking washer.

**edit: I just checked, didn't remember/realize that the Crow's Foot "A" piece is also STEEL....I thought it was Aluminum?? My Bad!**

That's my perception of what's needed to replace the weak star washer.

T.C.

[jetmechmarty]

2H7-18561-00-00 and 2H7-18566-00-00 are available at Speed and Sport in extremely limited quantities.

[TopCatGr58]

Okay Tom,

That makes more sense to me now...I'm just surprised that the shift lever has that much movement while shifting!

SO...now the question(s) are...I know Yamaha made that machined piece that looks like an "A" for 2 of the spots,....then had the shift drum NOT drilled as deep so that the PINS would stick out to act as the stops for the other locations....and so needed the FLIMSY THIN star washer to HOLD the pins in place and allow them to act as the pawl lever stops. The "A" piece and it's prongs do NOT hold down any pins, the star washer does that for the other stop positions of the drum!

SO....my idea now would be to get a washer THICK enough to equal the thickness of the "A" piece as well as the depth of the pins AND Star plate on top of them. Then use a dremel or grinding/cutting wheel and cut the lobe/stop shapes out of the THICK washer. THEN just grind the dowels down so that they are FLUSH with the surface of the shift drum, and then just secure the now THICKER STRONGER Star plate/washer onto the end of the shift drum.

IT just seems like once again Yamaha complicated the design of a part but ended up making it inherently weaker than it needed to be....ie. the cam chain tensioner assembly.

T.C.

[3Phase]

How does this look?

I've been looking at the assorted Loctite pin, sleeve, and bearing retaining compounds.
I don't trust Loctite alone to hold the dowel pins and I don't want to go fishing again:
Magnetic Fisher:



The Shift Pawl Assembly:


The Shift Drum:


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[TomB]

Hey Scott/fellows,
...but later Tom and Tod say that the protrusions actually don't engage or hit anything??
T.C.

Whoa!! NO! They are hit by the shift quadrant stops.

The red circled riveted in stops hit the pins in the selector drum

[TopCatGr58]

Hey Scott/fellows,

I haven't played with the spare engine and shift parts I have because the engine is stuffed way into a corner with a bunch of other stuff in front/around it!

Earlier in the discussion Scott, you said that the protruding longer pins engaged against the shift pawl "Frame" or such to prevent overturning/rotating...but later Tom and Tod say that the protrusions actually don't engage or hit anything?? Perhaps Yamaha had first designed it with the protrusions to do just that, engage another aspect of the shift pawl aside from the actual teeth of the pawl on the pins to help/assist in stopping over rotation, designed is for such...but then later realized it wasn't necessary, but already had everything else designed/manufacturing processes in place and so didn't bother RE-designing it FLAT, and so we got stuck with the flimsy fautly star washer that does fail!?

SO...unless those other 2 protrusions separate from the star plate engages into something, then it seems to me that they could be ground flat along with the extra long pins...so that a thicker stronger flat washer could be used, and still FIT beneath the range of the shift pawl arms to that it wouldn't get hung up...the drum has 2 pins on either side to keep the star plate from rotating, so having those in the large washer should do the same so that you could use a simple LOCK washer!? JAT!

T.C.

[3Phase]

NW Vintage Cycle Parts doesn't even have any and they usually manage to find and stock some really obscure parts that have been discontinued, sometimes for decades. They charge a steep price but if they have the part(s) it beats doing the Forrest Gump stump around the country in person to check back rooms and warehouses.

Here's how Yamaha made the shift drum in a modern engine with insane horsepower and torque. Notice how it's all one piece and the only stupid little dumafetchits it's drilled for are the Neutral contact and spring. Even if they break, the worst thing that can happen is a little light bulb can't turn on, it won't leave you stuck somewhere unable to shift in or out of gear:-


2013 VMAX - VMX17D Yamaha Motorcycle SHIFT CAM FORK


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[BA80]

I had that link saved from a while back, didn't notice it was unavailable now.

[3Phase]

Mmm, yeah, Plate, Side 1 is obsolete, and they wanted over $11 for one of their fancy stamped springy steel starfish washers when they were still available.

I'm not overthinking it, the washer has to be thin enough to allow the shift pawl pin boss to clear it in both directions or it'll snag just like it did on the original washer, plus I'm replacing an unavailable $11 part with a 50 cent SS washer and I get to play with a sledgehammer and an angle grinder!

What could possibly go wrong?

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