High speed wobble

[Old Head]

Anyone get a high speed wobble with their 400? My back end to starts to wobble when topped out in 4th or 5th. Not sure if its the railroad rocks doing it. it also happened on a dirt road but i think there was a slight hump in the center.

[JDMThoughts]

Check your wheel bearings and Hubs. Maybe a possible bent rim.

[Unverfehrt400ex]

Bent axle or like he said maby a bent rim???

[Old Head]

I'll take a look at it, I know my tire pressures were good cause i check them almost every ride.

[Selland74]

mine did that because there was a bunch of tire sealant in one tire

[monstergt88]

it cant be the wheel bearings becuase there are no wheel bearings in the back on the 400ex or hub bearings. If your going on the dirt road its gonna wobble some because ur not getting good traction. But if your really worried about it check all they said above. axle, rims and be a big factor.

[ride_red666]

axle might be bent or rims

[firefighterjosh]

Jack your quad up so you can spin the rear tires. Grab the axle and jerk it. If it wobbles it is you carrier bearings and replace them ASAP.! If it dosen't wobble then it is prally a bent rim or some mudd packed into a rim. If your axle dosen't wobble start your quad still jacked up and put it in first and watch the rims and axle to see if it wobbles.

*make sure to block the front tires;)

[Old Head]

Well its not the the axle bearings. couldn't see any wobble in the rims. I guess its just a small fish tail that i'll have to deal with. Nothing where i lose control just gotta keep on top of it. I'm pretty sure my nieghbors 450 does the same thing. Same with my sons 00' 400.

R U sure its a rear end wobble?

I've had a whole bike wobble because the front end wasn't set up correctly with the same toe in.

[krt400ex]

its your carrier bearings....mine are bad and the quad does the same thing...it sorta wanders a little. just jack the rear end up, grab the axle, and try to wiggle it back and forth...if the bearing are bad, then it will wiggle

[Kaleigh]

could be your toe in.. bent rims or maybe lots of dirt or rocks in the tire..

[krt400ex]

Originally posted by Kaleigh
could be your toe in.. bent rims or maybe lots of dirt or rocks in the tire..


he said it is in the rear end, that wouldn't have anything to do with toe-in

[Kaleigh]

Originally posted by krt400ex
he said it is in the rear end, that wouldn't have anything to do with toe-in

sorry.. didnt read the whole thread.. just trying to give some help before i headed out..

[firefighterjosh]

What about the bearings the swing arm bolts goes threw?:confused:

[Old Head]

The front not tracking right may be it. everything is tight out back I'll have to mess with the toe this weekend.

Originally posted by krt400ex
he said it is in the rear end, that wouldn't have anything to do with toe-in

I had toe in set wrong, and it felt like the whole bike was wobbling.

(I think it was) your suggestion was a good one - get the bike up on a lift / on blocks so the rear end is fully suspended.

Yank on the axle to see if its loose. Could be as simple as tightening the rear axle nut and jamb nut. Could be the rear bearings are toast. Could be a rear rim being out of round. Could be a lump of fix a flat hardened in a rear tire. Could be a bent rear axle. Could be a worn swing arm bolt that has the rear end out of alignment.

Or it could be the toe in that's making the whole bike wobble.

[Old Head]

Well it seems I have an ever so slight play in the swing arm. Put the rear end up on block and get a slight bump when I put pressure on the grab bar side to side. can't see anything move though

[krt400ex]

grab hold of the axle and wiggle it forward and back when it is up on blocks. make sure that the bike is not being supported on the axle when you jack it up though, because that would make it harder to tell if the rear end is loose.

if it is loose, then you need new carrier bearings.

[Old Head]

Nope tried that, they are good and tight no matter which way I try to move the axle. Just waiting on all the stuff I ordered now so I can replace the swingarm bearings.

[krt400ex]

oh...

i never thought that swingarm bearings would do that, but i guess i just learned something

Originally posted by Old Head
Nope tried that, they are good and tight no matter which way I try to move the axle. Just waiting on all the stuff I ordered now so I can replace the swingarm bearings.

YOu poor, poor fella.....

There is NO other ATV repair that is more painful, more frustrating, more tedious, more difficult, or more unenjoyable than replacing the swingarm bolt.

[Old Head]

:eek: Yea so i've heard. hopefully since i've never sunk my quad in water or mud to that point it won't be so bad. It's winter so i'll just warm up the garage and take my time.