HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
odlaw19

A thought.... New YZ450 5 speed tranny...

6 posts in this topic

OK, this is just a thought.

Now that Yamaha have moved back to a 5 speed tranny on the YZ, what makes this transmission different from the YZ426's and are we going to the same problems experienced with this transmission?

I know that the 4 speed gears were wider than the 5 speed. Have Yamaha retained the same size gears and made the tranny "longer" as such?

This may have already been touched on......

Waldo.

YZ426

Share this post


Link to post
Share on other sites

What problems? I don't really think there where that many problems with the tranny's. A few people blew some gears out, but crap happens.

Share this post


Link to post
Share on other sites

Well, we just don't know yet, mate. We do know that the crankcases are new. Have they been widened to accommodate a stack of 5 beefier gears? Have the same case dimensions been retained (I hope) and the materials upgraded? We'll have to wait to find these things out.

You know, the current WR450 5 speed fits in exactly the same space as the YZ450 4 speed does, an I haven't heard about a great number of troubles with that unit, although there are obviously fewer of them around. But the 4 speed hasn't been totally indestructible, either.

http://www.thumpertalk.com/forum/showthread.php?t=326704

Share this post


Link to post
Share on other sites

i read (can't remember where) that the cases were widened to accept the 5th gear,if ya do the math :bonk: i'd have to say they're of the bigger sort; but then thats not exactly factual :applause:

Share this post


Link to post
Share on other sites

I think I saw what you think you saw, too, but I can't remember where either. I do seem to recall that I discounted it because it either sounded made up, or the source wasn't on my high credibility list. My understanding is that the YFZ quad trans is wider, so maybe they went that way. But it seems to me that most of the failures of the 426 5 speed were in the dogs wearing round so they wouldn't stay in gear, rather than breaking gear teeth because they were narrow.

I remember seeing a picture of the left side of the then new '05 YZ125 engine. Dirt Rider used this picture to suggest that the transmission shafts were stacked vertically to make the engine shorter. The truth was that they had mistaken the bearing boss for the shift cam as the end of the mainshaft, even though it was obviously two inches below the center of the clutch. :applause:

Right now, it's all early info, and I'll wait for the real stuff to come out when it does.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0