Transmission Gear Damage Questions

4 replies to this topic
  • wweagleflyer

Posted February 09, 2013 - 04:52 PM


I bought an 06 450F a couple of months ago, and when I recently went to check the valve clearances, I noticed some sand in the cylinder head (yes, I have found the Breather Tube Re-route thread). That prompted a complete tear down, and in doing so I also found little ball bearing balls down by the sump, which came from the index lever bearing. I have a couple of questions (I posted these questions to here http://www.thumperta...0f-index-lever/ but didn't get a reply):

1. I have already ordered the index lever for an 06 450F. I understand that the 07 part maybe better. Is the 07 part really a significant improvement, or has that index lever also had frequent failures?

2. Where can I get a magnetic drain plug so that I can better capture the ball bearing balls if this happens again?

3. I have inspected my transmission gears for damage. The attached picture shoes some small damage on the tip of one of the teeth on 1 gear (small gear of the 1st gear set). There is similar damage on a total of three teeth on that one gear. Since the damage is at the tip of the gear tooth, I am inclined to keep using the gear (I would have to replace the whole shaft since the gear is integral), but wanted to get some other opinions.

4. Is the wear pattern on the gear teeth shown in the picture typical?



Attached Thumbnails

  • GearTeeth.png

  • Geoffit

Posted February 10, 2013 - 01:29 PM


the 07+ wheel was solid so no balls to fall out the marking on the teeth of the gears is pretty normal looking I would be more concerned about the the dogs on the gears in the picture if the previous owner
managed to brake the index lever he might not have been easy on the rest of it.Check your clutch basket closely as well. Magnetic drain plugs are out there, on e-bay for sure. if you decide you need to replace some gears I have a fair amount of new and used ones. I'm in Colorado as well

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

Posted February 10, 2013 - 02:52 PM


The dogs actually look good. I guess those ball bearing levers used in the 06 models were just prone to fail. The clutch basket does have some minor imprints on it where you can see small indents were the friction disk tabs press against the basket. Looks pretty minor to me. Is there a certain depth of groove I should consider bad? The manual gives only vague information for clutch basket wear.


  • Geoffit

Posted February 11, 2013 - 02:38 PM


Maybe but the dog in the center of the picture has a 45 degree wedge on it that shouldn't be there the grooves can be a problem although not fatal on the back of the basket take hold of the steel plate that's held on by the rivets and try to move it back and forth if it's tight or very slight movement you can live with it but if that gets too worn the the rivet heads can pop off and mayhem will follow.

  • wweagleflyer

Posted February 11, 2013 - 08:33 PM


I think I see what you are talking about with the 45 degree wedge (rounded corner on the dog). I would have considered that pretty minor. Do you think that is something to be concerned about?

Attached is a pict of the clutch basket. I think the picture makes it look worse than it is (the way the wear pattern reflects light). There is only about 0.003" between the peaks and valleys on the wear patterns on the clutch basket tabs. There is zero movement between the steel gear ring and the aluminum basket. When I try to move the steel cover plate on the back of the steel gear (directly under the head of the rivets), I get slight movement back and forth.

Attached Thumbnails

  • ClutchBasket.JPG

Related Content


Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

1998 yz400f will not idle. by trolley

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  32 replies

Yamaha YZ450F 2017 by Chris.GVS

Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies

Should I buy this bike? help....... by Numsa Hul

Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies

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.