WR 450 gear box blow up @ 3000 km


14 replies to this topic
  • Kountry_kid

Posted November 01, 2010 - 01:31 PM

#1

i know of a few 2006 WR 450's that as soon as they reach 3000 km the gear box blows up. just wondering if anyone else has had this problem.

Kountry_Kid

  • dustdogg

Posted November 01, 2010 - 07:41 PM

#2

Yeah, Yamaha installed a timer on 06' models so this would happen. Hah J/K - what kind of a question is this?

  • Kountry_kid

Posted November 02, 2010 - 10:17 PM

#3

Yeah, Yamaha installed a timer on 06' models so this would happen. Hah J/K - what kind of a question is this?

thats a silly answer. its a common question

  • miweber929

Posted November 03, 2010 - 04:13 AM

#4

If it's a common question, then you should read the common answer!!!

Anyway, you can never know when or how something like a gearbox will go. Ride in 5th wide open on pavement with low oil and it'll last hours; ride slowly on soft soil, shifting easily using the clutch every shift and it'll last probably forever.

Sounds like from other posts I've seen, it's not a "common" problem with normally ridden machines.

  • Krannie McKranface

Posted November 03, 2010 - 09:15 AM

#5

"I have a friend who...." or "I've heard that...." posts are fishing for conflict.

All bikes break if treated badly.

There are no 'known' transmission issues with the YZ/WR line.

  • grayracer513

Posted November 03, 2010 - 09:50 AM

#6

It's less of a case of it being a common problem than one of it being one of the only problems the bike has. My impression is that it is almost entirely an issue with the '03-'06 models, which had a narrower trans assembly, than with the later units, and generally with 5th or 4th gear. I've heard of it, but never seen it, and I wouldn't go so far as to call it common.

  • dustdogg

Posted November 03, 2010 - 08:36 PM

#7

thats a silly answer. its a common question


Sorry you didn't catch my sarcasm. I think the general concensus is that WR's have a good reputation for reliability and with the proper care should last as long or longer than most other bikes in its class. If you are in the market for one, look for one that is clean and has been well maintained and you will be fine.

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

Posted November 03, 2010 - 11:29 PM

#8

thanks guys

  • dazzabb

Posted November 04, 2010 - 11:36 PM

#9

It does seem to be fairly common.

There are three WR450's in our group an 04, 05 and 06.

All 3 "lost" 5 gear at some stage and all three need the same three parts to fix the problem.

I recently spent $300 on parts and a weekend rebuilding the gearbox on my own bike.

  • miweber929

Posted November 05, 2010 - 05:11 AM

#10

I'd imagine if 5th goes out you spend a lot of time topped out in 5th on the road. The gearbox, hubs and oiling system are designed for a dirtbike, not a streetbike. Which is why, contrary to what everyone wants to believe, a factory built dual sport is so much heavier than a dirtbikes. Honda XR650l's don't use a cush drive sprocket system and therefore tear the hell out of countershafts.

So while it may be a common problem, it's commonly explained.

  • grayracer513

Posted November 05, 2010 - 08:09 AM

#11

I'd imagine if 5th goes out you spend a lot of time topped out in 5th on the road. The gearbox, hubs and oiling system are designed for a dirtbike, not a streetbike.

None of this has any basis in fact. In the first place, the transmission in a YZF/WR/YFZ is pressure lubricated directly from the oil pump that feeds the rest of the oiling system. It's one of the best setups in terms of lubing the transmission that any bike has going for it.

In the second place, there is little evidence that the problem relates to lubrication at all. The teeth are not wearing off of the gear, and if running long distances in 5th, the gear turning at the highest speed relative to the shaft on which it turns is the low gear wheel on the countershaft. 5th is locked in place.

The problem is usually related to the locking lugs on the 3rd pinion and/or the slots in the 5th pinion into which they engage, and can usually first shows up as a jerking feel under a load in 5th. Continuing to operate the trans like that can lead to the 5th pinion breaking, or the lugs breaking off of the 3rd pinion. It actually has less to do with lube than with frequent shifting, high mileage (resulting in a high number of total shifts), or "lazy" shifting that results in the gears grinding a bit as they engage.

  • miweber929

Posted November 05, 2010 - 10:02 AM

#12

I stand corrected, which is why I started with "I'd imagine" and probably should have read "I believe"!

However, I still stand by the statement that the transmission and drive train was not designed for high-speed running longevity while doing a street riding style. With only a quart or so of oil in the sump, it doesn't take long for it to heat up and breakdown and any "normal" wear would be amplified. Again, Honda's XR650L has many issues with the drive system because of the stress a non-cush drive system. Frequent oil changes would help I'd imagine and lubrication also helps gears grab each other torsionally as well as directly on the face.

Without knowing the exact problem and fix, I am simply guessing. But 5,000 miles on a streetbike is nothing where 5K on a dirt-bike is a lot. You'd most likely have replaced a clutch by that time where street clutches can easily go 10x that in my experience.

So there is a transmission "issue"?

  • grayracer513

Posted November 05, 2010 - 10:14 AM

#13

So there is a transmission "issue"?

Arguably...

  • dazzabb

Posted November 05, 2010 - 06:01 PM

#14

The problem is usually related to the locking lugs on the 3rd pinion and/or the slots in the 5th pinion into which they engage, and can usually first shows up as a jerking feel under a load in 5th. Continuing to operate the trans like that can lead to the 5th pinion breaking, or the lugs breaking off of the 3rd pinion. It actually has less to do with lube than with frequent shifting, high mileage (resulting in a high number of total shifts), or "lazy" shifting that results in the gears grinding a bit as they engage.


Exactly what happened to our bikes!

I was surprised to find no damage at all on any the actual teeth.

The lugs had worn down, but had not broken and there was severe wear on the side of the selector fork.

PITA having to fix it, but should be good for a few years now!

  • baha

Posted November 05, 2010 - 06:11 PM

#15

I am not rideing as we type do the WR 5th gear in my YZ, yeah it seems to be a noted
problem on the WR gears only.




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.