Honda TRX 450R banner

1 - 16 of 16 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
I got a 04 trx450r. Oil filter has shavings in it, they are aluminum. I pulled topend apart and looking down into crank it has no play. And the thrust washers are still there and look in good shape. Any ideas? The quad also made a loud noise wich i thought was from the hrc cam but i guess not
 

·
Making HP ain’t free. . .
Joined
·
3,986 Posts
How’s the inside of the valve cover look? Did the bolts back out and rub against it?

You say the crank has “no play” that’s probably your problem, all cranks have side to side play.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #3
Pulled the valve cover off and it looks brand new. Cam sprocket bolts didnt back out. Cam chain tensioner still works. Looks like cylinder is in great shape, as there are no vertical lines only cross hatch. Piston looks very good. Im not gonna put this motor back in the quad until i know where the shavings are coming from, any help or recommendations are greatly appreciated
 

·
Registered
Joined
·
12 Posts
Discussion Starter #6
Would it be the bearing or the left case you think? Im gonna have to send it to a shop to split the cases, i dont have the tools
 

·
Registered
Joined
·
367 Posts
I'm going to say the crank is starting to fail you just caught it right in time.

As for Crank Play as far as I know you do not want to see any crank play at all. As for the Rod it's normal to have very little side to side play but not much at all.

I would suggest you to pull the stator cover off then push and pull on the flywheel and make sure you do not hear a metallic "Clunk" or have any movement, if it does and it moves then the left bearing has let go of the left case half causing the crank to walk side to side and it causes it to pinch the Thrust Washers and create metal shavings.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #8
Ok thanks for replying, this is probably a dumb question but with a bad crank bearing will I have to replace the case and crankshaft too? I will do both bearings and all new gaskets no matter what, I would just like to save some money if I can
 

·
Registered
Joined
·
367 Posts
I always suggest to replace the left crank case to be honest just because I don;t want my word to make me look bad.

So as long as the new left bearing does not just drop into the left crank case it should be fine to re use the left case.


When crank failures occur they can happen in 2 ways which is (1. Most commonly) is that the Left Crank Case lets loose of the outer left bearing race. Secondly (but less common) is the left inner race of the left bearing lets loose of the crank shaft.

Basically the Left bearing inner race should ALWAYS be a press fit on to the crank shaft and same goes for the left bearing when it goes into the left case.

I can't say this enough DO NOT use hot rods bearings when rebuilding a bottom end. It's okay to use their cranks but use OEM bearings with their cranks.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #12
Ok, so what I’m gathering is if the bearing just slides in the case it’s too far gone. If it requires a press to go in then I should be fine? Do you guys know anywhere to find a Manual for one of these? I would like to do all the work myself if I can, but it will be my first time doing a bottom end. I’m pretty mechanically inclined and have rebuilt 2 stroke top ends, you think I should give it a go myself or just be safe and send it to a shop?
 

·
Making HP ain’t free. . .
Joined
·
3,986 Posts
I’ve never seen a bearing just simply slide in, but you should check the fit.

Best bet is to buy a Honda service manual. You’ll also need a few specialty tools, and a quality torque wrench. Then figure over $1000 for parts. I suggest at least having the crank trued and welded, and preferably balanced to the piston you’re using, of course that will up the price of parts quite a bit. And that doesn’t include the price of a new left case which is about $300-$330 right now. Make sure you replace all the seals and any bearings that have had metal sent through them, and if the motor has had a lot of time on it I would just go ahead and replace all bearings. You’ll need a blind bearing puller to do that, Motion Pro makes a puller set for about $175, or you can buy the cheap one from like Rocky Mountain ATV for like $70.
 

·
Super Moderator
Joined
·
2,304 Posts
I'm going through this same thing right now. I had bronze shavings in my filter and pulled the motor right away. The big end bearings in the crank were shot. When I split the cases, there were shavings EVERYWHERE and my left case looked just like that (slightly shaved down). I found that my transmission bearing was chunky too. I just replaced all the bearings and seals because it really wasn't that much more. All bearings, seals, gaskets (bottom and top end), piston rings were about $600. That doesn't include the crank. I haven't decided what I want to do with that yet. OEM for $330 or new rod and Millenium weld and balance on my old crank halves for $400. It's the end of the season anyway so I might just make it a winter project.

Good Luck!
 

·
Registered
Joined
·
12 Posts
Discussion Starter #15
Bummer man... I’m definitely making this one a winter project, can’t afford to fix it right now. Well at least snowmobile season is upon us.
 

·
Registered
Joined
·
76 Posts
Just had my bottom end rebuilt which was $1500 and I went with oem, and had them put new transmission bearings in, definitely cheaper if you do it yourself but just don’t have the time.
 
1 - 16 of 16 Posts
Top