Transmission gears updated from 2006/07 to 2008

Using various web sites to obtain the correct part numbers, I ordered a bunch of parts for my tranny rebuild.

I picked up the parts today, and I'm diligently checking the parts I received and comparing them to my parts list. In the end, I am missing two parts and I have a box with a part number I didn't order. First thought was, great, there goes NAFO. But then I read the box and it reads, "3rd/4th Pinion Gear Kit". I look at my sheet, and sure enough, I'm missing the 3rd and 4th gear pinion wheels. The bags on the individual parts are close to the same as my part numbers, but not quite. I call the dealer I got them from and he said he assured me they were the correct parts.

The box is labeled with part number 99999-03806-00. However, the bags inside have very similar part numbers, but not the same:

For the 3rd Gear pinion:

5JW-17131-00-00 is what I ordered

3P6-17131-00-0 is what I got

The 4th Gear Pinion:

5JW-17141-00-00 is what I ordered

3P6-17141-00-0 is what I got

I start to disassemble my transmission to put in the new parts when I immediately see that the 3rd and 4th gear pinion wheels are different on my bike than the parts in hand. See the difference below - 3rd Gear Pinion on left, 4th Gear Pinion on right (new parts the clean gears on the left in each picture) click image to enlarge:



So, I examine the parts, and see that the gears themselves are the same size and tooth count, and the shaft groves match up perfectly. I go ahead and install them and then come in the house to do some more checking. I find that Ron Ayers web site still lists all the old part numbers, but many others have the new part numbers (including the "kit"). I check for a 2007 bike, and they have the same part changes. So I finally check the 2008 and see that the gears are slightly different for the 2008 than for the 2006/07 and that the part numbers I received are the same numbers listed for a 2008 model tranny.

If you look at the gears, there is an extra engagement dog on each gear, and the receiving area of the gear where the dogs go into (not sure what that's called) has more area for the engagement. Also of note for whoever it was that suggested it earlier to me, the new gear dogs are "undercut" in that they are shaped more like a mushroom than just a rectangle.

This has me wondering if they identified an engagement issue that perhaps causes a bent shift fork in the 2006/07 models and corrected it for the 08's?

Hmmm....Interesting thought.

BTW, when you finish this endevor, you need to buy yourself one of those sets of brass balls to hand from the back of you bike as you will have earned the right.

Nah!

A five dog gear offers easier shifting. The gear has to rotate a maximum of 1/5 of a revolution to engage its dogs. The old gear can rotate up to 1/4 of a revolution to engage.

The 3rd and 4th pinion gears are odd ducks in this transmission. They could rotate up to a 1/4 revolution before engaging their dogs.

All the other dogged gears offer a maximum of 1/6 rev before engagement. They have 3 dogs but there are 6 receptacle slots on the adjacent gear for the dogs, hence a maximum 1/6 rotation.

If you look at the other side of the 3rd gear in your photo you'll see 6 positions rather than 4 or 5.

Faster dog engagement equates to easier shifting. Somebody must have decided to do a little housekeeping and said lets clean up the transmission, specifically the 3rd and 4th pinion gears.

Yamaha's newer designs tend to have '5 dog' gears.

---------------

From the Yamaha Canadian site:

2008 FJR Info

*** Revised 3rd and 4th pinion gears feature an additional engagement dog for improved shifting feeling.

Constant Mesh said:

Nah!
A five dog gear offers easier shifting. The gear has to rotate a maximum of 1/5 of a revolution to engage its dogs. The old gear can rotate up to 1/4 of a revolution to engage.

The 3rd and 4th pinion gears are odd ducks in this transmission. They could rotate up to a 1/4 revolution before engaging their dogs.

All the other dogged gears offer a maximum of 1/6 rev before engagement. They have 3 dogs but there are 6 receptacle slots on the adjacent gear for the dogs, hence a maximum 1/6 rotation.

If you look at the other side of the 3rd gear in your photo you'll see 6 positions rather than 4 or 5.

Less needed rotation equates to easier shifting. Somebody must have decided to do a little housekeeping and said lets clean up the transmission, specifically the 3rd and 4th pinion gears.

Yamaha's newer designs tend to have 5 dog gears.

---------------

From the Yamaha Canadian site:

2008 FJR Info

*** Revised 3rd and 4th pinion gears feature an additional engagement dog for improved shifting feeling.

Click to expand...

His name *is* Constant Mesh, so automatically he is right on this topic. Even so, the post sounds spot on.

-BD

ponyfool, what's the wear condition of your 1st gear dogs? Many complain about the neutral-to-1st shift bang and lurch when a bike is motionless. Just wondering if one could see evidence of this on the 1st gear?

While you've got your engine broken open you might consider changing a component on the middle drive assembly just below the transmission shafts.

From the Yamaha Canada site for the 2008 FJR:

*** Middle gear damper spring load is increased for improved feeling at clutch engagement and better shifting feeling overall.

On page 5-85 of the service manual this damper spring is shown. Don't know what changed except maybe they upgraded to a stronger spring. Probably not an expensive mod while you're in the beast.

wanted to say thanks to Scott...

Much appreciated your passing along the discovered info about the 08's. That includes everyone contributing actually. It's good to see yamma working to improve things. This (gear dogs) was one that I found disheartening, very happy to see progress here.

thanks again and hope yer gettin it fixed Scott.

Glad to see that rather than fixing a problem, it's just an improvement. I've never heard of 3/4th gear shifting problems, and I certainly haven't had any. I don't race or abuse my tranny in any way, so hope to have a healthy tranny for the life of the bike with me, which shouldn't be more than 20K miles. Good day.

JC