Parts interchange info


17 replies to this topic
  • pscook

Posted February 16, 2010 - 06:17 PM

#1

Here's a bit of a stumper-

I am looking at replacing third gear in a WR426 transmission, both sides (pinion and gear). I have the part numbers from both bikes. Can someone tell me, just by looking, if they are the same parts, or maybe what the difference is? I had heard that the trans for the 2004 was an upgrade from the 2003, and am hoping that I can upgrade the 2000 WR426 to 2004 WR450 specs because I don't like splitting cases to repair gears. Again and again. Headgaskets get expensive after a while.

3rd Pinion
WR426- 5BF-17131-20-00
WR450- 5TJ-17131-00-00

3rd Gear
WR426- 5BF-17231-00-00
WR450- 5TJ-17231-00-00

Thanks for your help, it is appreciated.

  • pscook

Posted February 17, 2010 - 01:18 PM

#2

How about this-

Does anyone have a WR450 transmission sitting out that I could borrow/rent? If it's not local to Seattle I would obviously cover shipping both ways, so let me know if you have one that I can borrow to compare to my 426 transmission.

  • BajaFool

Posted February 18, 2010 - 01:45 PM

#3

The third gears for both bikes are the same. The third gear pinions are different. I can't say what the difference is. The first three positions of the part number are the model type and year. Yamaha has a code for this and you can do a Google search to find it. The rest of the part number is what to look for regarding compatibility. If all of the numbers are the same, then they are the same part in every respect. If the numbers are different, then there has been a change in one of the parts you are comparing. It could be as minor as paint color or as major as a new shape, new material or a new production process. This change may still allow the parts to be used interchangeably, however, the parts are different.

  • pscook

Posted February 18, 2010 - 03:21 PM

#4

I figured that the first were year/model indicators, the next set was configuration (shape, size, etc), but the following sets were what threw me. Sounds like I am on the right path. Unless the "20" on the 426 pinion is a deviation from the earlier configuration and the 450 incorporated the new configuration with a part number roll. Complete speculation and conjecture on my part, of course.

I pulled together a spreadsheet comparing the 2002, 2003, and 2005 WR transmissions, and so far there are exactly three major model differences (excluding the 5BE/5TJ designator) between all of the part numbers. The parts that are different are a seal, a washer, and the drive shaft. Drive shaft is probably different because of the clutch hub, hard to say. What's interesting is that one part was used on the 426, not the 2003 450, and then used again on the 2005 450. Curious.

Anyway, if someone has a WR450 trans that they would ship me (at my expense) I would like to compare parts between the YZ426, WR426, and YZ450. If my hunch is correct, the gears from the 426 and WR450 models will interchange, providing a much wider selection of gears for those that like to modify stuff. Like me. Or options for those that have bad gears and want to upgrade. Like me.

  • grayracer513

Posted February 19, 2010 - 09:48 AM

#5

There limited interchangeability in the gears you listed, and I'm not sure how far it really goes.

The shift forks will interchange between the 426 and 450. Also, the output shaft, 2nd pinion, 1st wheel and 5th wheel are the same.

All 5 of the internal ratios are the same. The 450 uses the same shift cam as the YZ250F, while the 426 uses its own. My understanding of the matter is that the main shaft was upgraded along with the 3rd, 4th, and 5th pinions in order to reduce failures in the top two gears, and that the use of the 5NL shift cam in place of the 5JG was a part of that fix (modifying the position and travel of the 4-5 fork that slides the 3rd pinion). Note too, that the clutch boss is different between the 426 and 450.

I have heard it said that the main shaft and shift cam are the sticking points, but I don't have anything specific as to why. I do recall that someone who installed a 426 5 speed in an '03 YZ450 had to do a bit of machine work to fit it, whereas the WR450 trans drops straight in.

********

On the part numbers, Yamaha uses a "basic number" system, as do Ford, Honda, and others. The three character prefix is the vehicle for which the part was originally produced. The second set of 5 digits (usually) is the basic part number. All clutch bosses are 16371's, all cylinder heads are 11102's, etc. The 3rd and 4th sets of two characters each are indicators of alternate sizes or minor revisions, normally. An example is the intake cams for an '03, '06, and '07 YZ450:
5TA-12170-00-00
5TA-12170-10-00 &
5TA-12170-20-00, respectively. They all interchange, but they're all a little different. You'll see this with carb needles, GYT-R flywheels, etc.

The "Model Designator" doesn't mean all that much, unfortunately. 5TA was an '03 YZ450, and 5XD was an '05. A lot of stuff interchanges between these two, and with the 5TJ WR450, and other models as well, so the only guarantee of interchangeability you can get from the part number is when they are the same.

Part numbers for basic hardware and bearings follow an entirely different scheme. Bearing numbers are issued sequentially. Bolts occasionally have a special part number as above, but the number given them usually tells you the type, thread diameter, and length.

  • pscook

Posted February 20, 2010 - 10:32 PM

#6

Thanks for the clarification, Gray. I knew that it couldn't be as easy as I wanted it to be. Why couldn't Yamaha have issued an upgrade that could be used on the older bikes? So, the issue was just with the 3rd, 4th and 5th pinions? If so, that simplifies my purchase requirements to repair my transmission. The YZ trans only skipped in 5th, the WR skips in 4th and 5th. I knew that 3rd was involved, but I didn't know which gear of the pair was the offending suspect.

However, since I'm interested, I will keep my eyes out for a reasonably priced set of gears for the 450 and see if they will work in my 426, because it sure would be nice to have a trouble free gear box in this bike at some point in the future.

  • grayracer513

Posted February 21, 2010 - 12:38 PM

#7

The YZ trans only skipped in 5th, the WR skips in 4th and 5th. I knew that 3rd was involved, but I didn't know which gear of the pair was the offending suspect.

Whenever you have a gear skipping, it's always the gear with the locking lugs, and the gear on the same shaft that is moved by the fork to lock it. In the case of 5th, it's always going to be 5th and 3rd pinions, never the 5th wheel, unless there's collateral damage.

  • pscook

Posted February 21, 2010 - 05:11 PM

#8

Whenever you have a gear skipping, it's always the gear with the locking lugs, and the gear on the same shaft that is moved by the fork to lock it. In the case of 5th, it's always going to be 5th and 3rd pinions, never the 5th wheel, unless there's collateral damage.


Very many thanks, Gray. I just spent 5 minutes running 3rd through 5th on the Yamaha parts website and your explanation makes perfect sense. Since my 5th pinion is (almost) new I will be replacing the 3rd and 4th pinion to rescue those gears. Probably replace the shift forks too, since I obviously have too much money in my pockets right now. Oh, and a head gasket. Anyone have a Yamaha parts hookup that can beat Bikebandit for prices?

  • pscook

Posted February 25, 2010 - 02:01 PM

#9

Gray (or anyone, actually)-

Is this the shift fork that engages 3rd pinion on the WR426?

FORK, SHIFT 2 5BE-18502-20-00

I'm ready to pull the trigger on a box of parts, and I want to make sure that I get the right fork for 3rd gear.

phil

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • 123BigcoopDawg576

Posted February 25, 2010 - 02:22 PM

#10

5BE-18502-20-00


FWIW I googled your part number and here was the cheapest price I could find (about 12 bucks cheaper than Bike Bandit)

http://www.boats.net...8502-20-00.html

  • pscook

Posted February 25, 2010 - 03:20 PM

#11

FWIW I googled your part number and here was the cheapest price I could find (about 12 bucks cheaper than Bike Bandit)

http://www.boats.net...8502-20-00.html


That site is very cool. I can save about 10% over the Thumper Talk store, and that includes the 5% coupon for taking the survey. Very cool stuff, thanks for the link.

But, is that the fork that engages 3rd pinion?

  • grayracer513

Posted February 25, 2010 - 06:13 PM

#12

Gray (or anyone, actually)-

Is this the shift fork that engages 3rd pinion on the WR426?

FORK, SHIFT 2 5BE-18502-20-00

I'm ready to pull the trigger on a box of parts, and I want to make sure that I get the right fork for 3rd gear.

phil

Yep, that's it.

  • 123BigcoopDawg576

Posted February 25, 2010 - 08:34 PM

#13

That site is very cool. I can save about 10% over the Thumper Talk store, and that includes the 5% coupon for taking the survey. Very cool stuff, thanks for the link


Thats my biggest complaint about the TT store....they have everything but their prices aren't the "cheapest" :thumbsup:

Sure they'll price match it but that requires way to much time and effort on my part....:ride:

  • pscook

Posted December 06, 2010 - 03:42 PM

#14

Up to the top!

If anyone has any WR400, 426, or 450 (or WR250 as well, I won't discriminate) transmission gears lying (laying?) around their shop I would be interested in purchasing or renting them for comparison to my WR400 and YZ426 transmission.

I am specifically interested in pairs of gears, to see how they fit on the shafts and interact with each other. Any gear set, as long as they are a matched set. The more gears I get the better interchange info I can put together.

Drop me a PM and we can discuss my situation/circumstances.

Thanks!

  • 5valve

Posted February 14, 2011 - 06:28 AM

#15

I'm in need of a clutch boss (hub) for a WR 450 '04.

As there are many 2nd hand or NOS for sale, there is a problem finding the '04 model, coded 5TA-16371-02-00, which is YZ and WR 450 '04 only.

For '05 til '08, the code is 5TA-16371-10-00.

As grayracer said, only minor diffrences are in the last digits; read somewhere it could be cushioning diffrence.

Final Q, could the '05-'08 clutch boss be used in the '04, with '04 basket, plates, springs etc

  • grayracer513

Posted February 14, 2011 - 08:29 AM

#16

The only difference I see is that in '05, the WR went from 9 to 8 friction plates. Since the same clutch boss is used in both YZ and WR models with 8 or 9 plates, I don't see why it won't work to use the '05 (5TA...10) in yours.

  • alexo

Posted November 15, 2014 - 08:22 AM

#17

Hello all,

I'm trying to find out if I can bolt on a complete clutch set from WR 2005 to 2004 model?

Will that work? I see different part numbers for the basket, which concerns me :blush:

Thanks!



  • grayracer513

Posted November 17, 2014 - 05:13 PM

#18

The basket has a different driven gear on it that requires the use of the '05 crankshaft drive gear with the basket.  Otherwise, it will interchange.  Yamaha changed the primary reduction ratio in '05.  The difference can be compensated for by going to a one tooth smaller front sprocket along with the later parts.






 
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