Question on the Transmission

[bthompson]

I've got an '00 400ex that one day just started slipping in 3rd gear. If i was light on the throttle i could accelerate a little bit but if i was over 1/4 or half throttle it would slip. Now i have the case split and i was hoping to see some teeth laying in the bottom but everything looks fine. I can see some wear on the countershaft from where the middle fork goes. So my question is do i just need to get a countershaft off ebay or is it in the forks, and if i get one off ebay is there any way of knowing it won't have this same problem cause all the gears look fine?

[250x_kyle]

to be honest it sounds like it was a clutch plate being wore issue. my 450r acted like that when the clutch was junk. as far as tranny issues if it goes into gear i have doubts its the fork.

[ish416]

Definitely sounds like a slipping clutch. If it were the tranny it would be jumping out of gear all the time and be hard to shift or just wouldn't shift.

I would replace your clutch plates and get a new counter-shaft sprocket. Also, check to make sure your clutch basket isn't grooved. That's what happened to mine several years ago.

[bthompson]

would the clutch only effect 3rd gear?

[ish416]

It should affect all gears. It could be that you don't notice in first or second because of wheelspin or something and 3rd is where it first becomes noticeable.

If the shift forks were messed up it usually affects all of the gears.

[bthompson]

I've tried to get it to do it in all the other gears and 3rd is the only one it does it in. Slip may not have been the right word to describe it, it felt more like i had stripped all but a couple teeth off the gear, so it would grab hard, then nothing, then grab again. It would do this all the time if i was accelerating hard in 3rd. I've looked my clutch over and it looks fine, so im still thinking its something to do with the countershaft but im open to any more ideas.

[brokenmike]

Transmissions like these do not slip! It either has another neutral, does not go in to gear, comes out of gear, locks up, or feels jumpy. The clutch is the only thing that will slip. I would say it is the clutch

[Honda5]

You probably have rounded the dogs off of third causeing it to not stay in. That is not uncommon in transmissions that old. You probably need to replace the fork and third gear and the gear it Tidwell also. It is not your clutch.

[CJM]

Chances are the dogs of the gear are no good. Not an easy fix really b/c of how much you need to take apart however. When your in there look for signs of other wear and replace everything or get a good used trans instead.

[bthompson]

Good thing ive already got it split apart then lol, ive seen plenty of transmissions on ebay so ill prolly start searching on there now. Thanks

[Honda5]

Check all your gears , dogs and slots for wear if it's only 3rd you might be better off getting new. I should have a couple 400 ex trans let me see what I can find.

[bthompson]

That would be great, thanks

[bthompson]

I found a trans on ebay, so now i just need to know of a good complete gasket kit? I saw cometic's kit on rockymountain but it didn't have very good reviews because they said it was missing some of them. Any ones you guys would recommend?

[Stickman400]

Honestly I'd just buy stock ones. You can find full stock kits at motosport in the OEM parts section. That way you know they are a perfect fit and wont fail. The Cometic ones are paper and they aren't cut right and barely even line up with the bolt holes and oil passages. I bought one for my clutch cover awhile back and it didn't even have the bolt holes in some spots and the oil passage holes didn't even line up.

EDIT: Go on http://www.motosport.com/atv/index.php and find your wheeler under the OEM Parts tab and scroll down till you see Gasket Kit B. It has all the gaskets, seals and o-rings for the entire bottom-end. You might have to call them to make sure what you need if you don't need them all. They have terrible descriptions of them.

[bthompson]

sounds good, thanks a lot