rearend problems still

[stick400]

I'm getting tired of throwing money at this trying to fix it and its hard to tell whats bent or wore. I have so far replaced the axle which was used but looked almost new. I replaced the hubs, a wheel, and new tires and it still has a wobble in it. The wobble gets worse in the higher in rpms and is unbearable at wot. Could my carrier be bad at causing this? I believe the brake disc hub might be bent but this shouldn't cause the rearend to wobble correct? Please any advice is apperciated. This thing is really pissing me off. This is a 01 400ex btw.

[85atc350x]

Have you tried having one of your riding buddies ride behind you to watch for anything wobbling??

[pnut420]

Check the carrier for sure, if it is stock chances are it may be fried, could have got a bearing hot and it cracked, Id check that out for sure, brake disk would do some but you would really feel that while braking if it were that... Id look towards the carrier.

[stick400]

I sat it on a jackstand and went through the gears and it was wobbling pretty good. I replaced the bearings when i put the axle in and checked the carrier. It was cracked but had knicks in it where someone else had put bearings in before. Would a bad carrier cause the wobbling? Can i use an aftermarket carrier with the stock axle if thats the problem?

[stick400]

meant to say it wasn't cracked

[pnut420]

Originally posted by stick400
I sat it on a jackstand and went through the gears and it was wobbling pretty good. I replaced the bearings when i put the axle in and checked the carrier. It was cracked but had knicks in it where someone else had put bearings in before. Would a bad carrier cause the wobbling? Can i use an aftermarket carrier with the stock axle if thats the problem?

Yeah you can use a aftermarket carrier with stock axle. A bad carrier could cause wobbling. Is hard to say without seeing it, but if the carrier was bad it would wobble different then if the axle or hubs were bad. Does it all seem tight when you bolt it together or does it have play?

[rneal]

Also check the needle bearings in the front of the swing arm. It could be your entire swingarm is moving.

[pnut420]

Originally posted by rneal
Also check the needle bearings in the front of the swing arm. It could be your entire swingarm is moving.

True Ive had them freeze up on me, I guess they could crack easy also. It should be noiticable weither its the entire swingarm or just carrier.

[stick400]

going to try a few things tomorrow night and check the stuff that was that mentioned. Hopefully I can get it fixed.

[QuadRacer041]

put it back up a jack stand and run it with the wheels off at leaste that way youll eliminate the wheels for sure.it is also VERY posible that the axle you boughtr that wasnt new but look new could be bent as well.

[stick400]

well i checked those few things and its still wobbling. I took the wheels off and it is wobbling on one side, so i guess the axle i bought was bent to.:mad: I can shake on the axle and it has no play in it so that should mean the axle carrier is good right? This really pisses me off buying another bent axle but i will buy a new one this time. Would a g force axle be good for me? I do mostly trail riding and if i hit any jumps they are very small.

[rneal]

Do your hubs fit nice and snug or do the wobble around on the axle? If there is any play that could be your problem. When you jacked your quad up did you lift it under the engine to check and see if the entire swing arm is moving or did you lift it by your skid plate and only shake the axle?

[400exdad]

If you can't see the end of the tire move around with it spinning then a bent axle isn't your trouble. I bent my axle pretty good once on the 300 and I couldn't even tell it at high speeds.

I would do a couple of things.

Since it seems you have already removed the tires, I would remove the chain and caliper and see how things moved. Are they smooth, is there any play? BTW, the way I tell my carrier bearings are bad are either with the quad on it grab bar and move it side to side or by standing on the pegs and rocking side to side... the smallest amount of play will show up. Especially with the quad on its back.

My next question would be why did you think you had a bent axle in the first place? Did you actually bend it? And then the wobble came after you struck something? If so, I would examine the swingarm for cracks. Also, is the front and rear sprocket in line with each other? You could have tweaked the frame and not know it. Worst scenario.

Finally, when you replaced the bearings, did you have any problems? When you pressed the bearings in, did you use the inner or outer race to do that? If you used the inner, there could be damage... like a cracked race. The races are hard, but brittle. Next, and this is elementary, did you put the spacer back in? Sorry, but I had to ask. The spacer is imperative to keep the bearing races from failing so you can tighten the heck out of 'em. :D

As far a a bent rotor, ours on the 300 has been warped for years... you can see it moving back and forth from the rear and can see the caliper move when we are lubing the chain, but again, it has never caused a minutes trouble.

Good Luck. I hope its just a loose lugnut.

[2001400exrider]

ohhh man....wobbling wheels are my BIGGEST pet peeve...cant stand them. my 400's wheels both wobble but iam pretty sure its the rims. ive already had a new carrier and bearing put in durring the summer. Although i might of made the mistake of putting in another stock carrier, i think i should of got an aftermarket one. Anyway if its my rims i know i will be getting some bran new Hipers in the near future:D

[stick400]

Well the hubs are all the way against the axle. I bought the four wheeler used and I thought it would only be a bent axle. One of my wheels are brand new and I have brand new bandits on both sides. I take the wheels off and watch the axle and it only moves some on one side. I have the four wheeler on the jackstand on the rear. I will move it under the motor and see what happens. There is no play in the axle from moving it side to side or any of the other things mentioned. I used the heating up method to put the bearings in and froze the bearings and they dropped right in will alittle tapping. Very lightly i may add. When i got the four wheeler home the day I bought it i noticed one of the hubs was loose so i took it off and tightened it back up. Hopefully i can figure out what it is and maybe some of the suggestions will help me find out what it is. If i do find out i will let everyone know. thanks

[stick400]

o yeah i did put the spacer back in.:D

[400exdad]

Sounds like you know what you're doing, so maybe we need to look elsewhere. Early you mentioned that at WOT, it was almost unbearable, but I don't think you said speed. Could it be that the motor is out of balance? I just noticed that you have a 440. Did you build it? Perhaps someone split that case and put the counter balancer timing in wrong.... the 400 does have a counter balancer doesn't it? Also, does it rev smoothly when not in gear.... you may have already mentioned it, but it sounds like the rear is in good shape.

Edit: I see that this is on your 2001, not the one in your sig, but someone still could have been in the case already if its had a hard life.

[kbh78]

it sounds like your used axle you got is bent that sucks but if you know a buddy with a press and a dial indicator its not to hard to straighten.

[stick400]

Well i bought the 440 kit and never put it on, just put it in the sig lol, but the shaking gets worse with speed not rpm. So it is worst at the top of fifth gear. Since i have two axles now i'm going to take one to a machine shop so they can see if its bent and if so fix it. 400exdad i see you live in Mississippi, you wanna make a road trip up to look at it for me lol? i really apperciate all the help guys hopefully i will find it out tomorrow night with some more work. Things like this make me wish i would have financed a new one.

[400exdad]

One more thing you could try. Loosen up the bearing slightly. If the axle is bent in the carrier, which I doubt, this will help.

Let us know what you find.