400ex rotor problems

[400exc]

yea, i have a 2002 400ex, and when i drive down the road, or slow down after accelerating, my rear brake rotor shakes and rattels, and doesnt sound too good. I am wondering why it is doing this, and if there is any way of tightening it in any way? And also, that big nut, kinda thing, on the right of the rotor, is loose too. I have changed the rotor before and am wondering if that might of made it do something wrong then? Why would it all of the sudden come loose, and has any one else experienced this problem before? I need to get this fixed, because it dont sound good, and gets worse every day. I dont see any where to tighten the rotor, or the nut on the right of the rotor. Also, the brake thing that holds the brake pads on so i can stop, that is loose too. Is it maybe because I slam on the brakes once and a while, making it break something, or making somethin come loose?Please help me with this problem, i need to stop having problems with my 400ex.

[aviator4]

that big nut, kinda thing,

This is the Axle Lock Nut. It's KEY to keeping the rearend together!!!! Tighten that thing down!! It acutally pushes against a clip that is on the tire-side of the axle, make sure it's tight and stays that way.


the brake thing that holds the brake pads

This is the brake caliper. It should be tight as well. Check to see if the caliper is tight on it's mount (the part that attaches it to the wingarm) If it's not, chances are the clip that holds the caliper mount has either broken or popped out of its groove.

Sounds like it's the Axle Lock Nut that needs to be tightened against it's clip. You might loosen it up to make sure there is a clip in the groove underneath the nut itself. If this is confusing you, I can take some pics to help illustrate.

[400exc]

ii know what your talkin about, but can u sedn pictures so i actually know what it is, to see if i am right? and the axle lock nut,. it moves a little, but will stop after about 1 to 2 mm's of a length, so what would it make it stop at a certain spot?

[400exc]

and, how would the brake caliper fall out of it natural place? is it becasue of slamming on the brake alot?

[aviator4]

I Will get you some pics this evening.

the caliper is probably loose because the lock nut is loose. It's all tied together... I will post some pics.

The lock nut will actually stop going both directions. it needs to be TIGHT all the way "out" on the axle.. exact reverse of what you think it should be.

Try tightening that and see if it sucks up some of the play.

[400exc]

well, when i try to tighten it with my hand, it will only go so far. why would it be doing that? so your telling me that becauise the axle lock nut is loose, that is why the rotor is loose? is this a simple procedure to fix? and thatnks for gettin me pic to show me how to fix it.

[aviator4]

Actually, we are adressing two issues here. First is that the axle lock nut is loosee. It's a two part nut. Take a look at the photo

1. is the outer retaining ring. It's a steel ring that is UNDER the axle bolt (you can't see it when the axle nut is on

2. is the axle nut itself, this pushes agains the retaining ring, keeping the axle (not in the picture) secure.

3. is the lock nut for the axle nut, once the axle nut is tight, the lcok nut is tightened down to keep it in place.

4 is the axle "bolt" This threads into the brake rotor hub and the axle nut and it's lock nut theads onto it on the other side.

5 is the brake rotor hub itself.

When you tighten the axle nut against the ring (1), you are actually "pushing" the brake rotor hub into a shoulder on the bearing inside the bearing carrier. If the axle nut is loose, it's possible that the rotor hub (along with the entire axle) is moving laterally in the bearing carrier (left to right), which is VERY VERY BAD. It can cause the bearings inside the swingarm to fail, and can cause the the brake's to make noise because it's shimmying.

[aviator4]

Okay, in this image you can see the following:

1. Brake caliper mount retaining clip

2. Brake Caliper mount

2a. brake caliper mount pin and nut

3. swingarm

4. bearing carrier

If the retaining clip (1) is missing or has come out of it's groove, the brake caliper mount (2) and the caliper itself (not pictured) will rattle- giving the symptoms you've mentioned.

The brake caliper mount pin and nut are VERY important. This is what keeps the caliper from rotating when you depress the brake pedal. Make SURE that this pin is in place, not broken, and that the nut is tight. Try to "wiggle the caliper mount to determin whether or not it's loose.

the groove for the clip is marked on the bearing carrier in this image, you can see where it sits. the retaining clip is a very large "C" clip. If it's come out of it's groove and is rattling around, you will need to remove the rotor and hip to get it back on.

does this help?

[aviator4]

Here's the image

[400exc]

Well, in the first picture u had for me to download, the axle botl on my 400, is loose, or it kinda looks like it is broken. the axle nut and lock nut are tight, but the bolt that they are on are loose. How would it make the barrings mees up inside? The bearing arent going out yet, and how would it make everything go bad inside? Would it pull them out of place because they are connected?In thie first picture again, #5 isnt connected to #4, that is why on mine, i think it is making everything go loose on me. So the axle lock nut is tight, and everything else, except for the axle bol which isnt connected to the brake rotor hub. I am going to take apart the whole rear end today, and see if i can get everything tight, and see what my problem is. I will give u the results of how it looks tonight, after I am done, and today is easter, so it might take until Monday, so i will give you the results by Monday. I think it shouldnt be bad, but now that you said something about the bearings going kinda out of place, now i am worried. I am going to take the rotor off, the brake caliper, the hubs, and then get to the bearings and axle lock nut and bolt. I hope it dont take long, and is easy to fix, is it? Tnaks you for taking uyour time to help me out on fixing my 400ex, but i will need you for just a couple more days though, just to get everything right.

[400exc]

And i dont think it is moving the rotor that badley, because it only moves so far, just like the lock nut. It only makes a shaking sound when i turn it off and coast, or when i go slow, like in 1st,2nd,or low 3rd gear. So i dont think it is in the worst shape it can be in yet.

[400exc]

well, i got it torn apart, and one of the bearings was bad, but, yet i got the lock nut to tighten, i just got to get new bearings, so as soin as i get those, i should be all god for a while