Rear Brake Rotor Loose

[BigJohn]

Is there anyway to tighten the rear brake rotor. It rattles and makes one heck of a racket when hitting bumps

[dshealey]

Is there anyway to tighten the rear brake rotor. It rattles and makes one heck of a racket when hitting bumps

Most of us never have had that problem, but seeing more posts about it now. BMW must have changed something that ended up being a bad change.

The rotor is a "floating" design, and has to have a little side to side movement, but it is supposed to be taken up with "wave" springs between the riveted flanged bushings and the rotor. Don't know if these wave washers are breaking or what.

At least one person has put a little red high temp silicone sealer between the rotor and bushings to stop it. Don't know how long it has lasted, but have not heard that it started rattling again.

You do not want to do anything that will totally defeat the float though, because the calipers have no type of float built in as many auto calipers do. Either the caliper or rotor has to have compliance built in.

[mintaka]

Is there anyway to tighten the rear brake rotor. It rattles and makes one heck of a racket when hitting bumpsReplace the "tired" wave washers ??

[dshealey]

Replace the "tired" wave washers ??

You can do that on the front, but not the rear. The rear rotor is riveted to the carrier, the front has screws.

[KMC1]

It's funny this just came up last week on a ride. It's driving me nuts. I'm also noticing the rear drive has a little play in it as well. Not good.

[mintaka]

You can do that on the front, but not the rear. The rear rotor is riveted to the carrier, the front has screws.Huh ? You posted in your initial reply to BigJohn's question re: REAR rotor rattle… The rotor is a "floating" design, and has to have a little side to side movement, but it is supposed to be taken up with "wave" springs between the riveted flanged bushings and the rotor. Don't know if these wave washers are breaking or what.

At least one person has put a little red high temp silicone sealer between the rotor and bushings to stop it. Don't know how long it has lasted, but have not heard that it started rattling again.

You do not want to do anything that will totally defeat the float though, because the calipers have no type of float built in as many auto calipers do. Either the caliper or rotor has to have compliance built in.
THEN YOU post… "Nope, the rear rotor (the one at issue in BigJohn's original post ) is fixed."

So………

1) You posit a requisite "float" for BigJohn's REAR rotor. How do you get that on his REAR rotor if your reply to me now states, "It's riveted" ?

2) How do YOU get hi-temp red silicone in between the rotor and carrier, if the rotor is riveted ?

Jeez, dshealey… ya claim the rotor is SUPPOSED to be FIXED (by rivets). Since the ROTOR RATTLES then one can correctly assume, IF the noise is truly coming from the rotor,

THE RIVETS MUST BE LOOSE :eek: :eek:

[LJSMITH1]

The rear rotor is actually floating on rivets. The rivets have c-clips on the diameters to take up the slack and to help manage the thermal expansion issue. You would need to replace the entire rotor/carrier assy if the movement is out of spec. I have no idea what the max amount of movement should be, but there is a little at room temp.

Good Luck!

-Larry :bmw:

[mneblett]

Jeez, dshealey… ya claim the rotor is SUPPOSED to be FIXED (by rivets). Since the ROTOR RATTLES then one can correctly assume, IF the noise is truly coming from the rotor,

THE RIVETS MUST BE LOOSE :eek: :eek:Ease up!

David didn't say the rotor was "fixed."

The rear rotor is, as he indicated, a floater -- i.e., a rotor held by intervening "buttons" to a carrier.

The rear rotor is, as he indicated, known to get loose and rattle on the buttons.

He also correctly said the rotor was riveted: In responding to the question of how to fix the rattle, he correctly noted that the buttons holding the front floating rotors are bolted buttons, while the buttons holding the rear floating rotors are riveted on. David never said the *rotor* was riveted on.

In the future, let me suggest that if you don't understand what is being said (or worse, assuming that you do understand even though you haven't looked into the details first), you'll be a lot better off saying "um, do I understand this right?" than flaming someone for trying (and in this case, correctly) to help others. Unlike many of the boards out there in cyberspace, this is a place where mutual respect and courtesy underlie the discourse.

You owe David an apology.


p.s. In response to a prior comment in the thread: putting goop in the buttons to stop the rattle doesn't work well -- it gets flung out quickly (BTDT)

[mintaka]

Ease up!

David didn't say the rotor was "fixed."

The rear rotor is, as he indicated, a floater -- i.e., a rotor held by intervening "buttons" to a carrier.

The rear rotor is, as he indicated, known to get loose and rattle on the buttons.

He also correctly said the rotor was riveted: In responding to the question of how to fix the rattle, he correctly noted that the buttons holding the front floating rotors are bolted buttons, while the buttons holding the rear floating rotors are riveted on. David never said the *rotor* was riveted on.

In the future, let me suggest that if you don't understand what is being said (or worse, assuming that you do understand even though you haven't looked into the details first), you'll be a lot better off saying "um, do I understand this right?" than flaming someone for trying (and in this case, correctly) to help others. Unlike many of the boards out there in cyberspace, this is a place where mutual respect and courtesy underlie the discourse.

You owe David an apology.


p.s. In response to a prior comment in the thread: putting goop in the buttons to stop the rattle doesn't work well -- it gets flung out quickly (BTDT)So be it.

David, I apologize for not understanding.

[BigJohn]

On my rear rotor it appears to be just large head screws that a allen wrench should tighten up. They do not appear to be rivits. There is no way to get at them with out taking the whole rear end out. I will probobly just live with it for now.

[mneblett]

Good on ya for takin' the high road. http://www.bmwlt.com/forums/images/icons/icon14.gif

[SCltc]

Just for your info my 02 has had the rear rotor replaced 2 or 3 times (I've lost count) in 52k do to major rattle. All were covered under BMW/Western ext warranty. At one time the tech put the bike on the center stand, held the rear brake pedal and was able to feel play as he pushed the wheel forward/backward. I would approach your dealer stating others have had this problem and may an unsafe condition. They may replace or help with some of the expense.

[dshealey]

So be it.

David, I apologize for not understanding.

No apology needed! As you said, it was a misunderstanding, and I did not help in the way I stated that the rear rotor was riveted on, meaning the flanged retaining bushings were riveted (per the earlier post), where the front ones are bolted and can be removed.

Hey, we all misread sometimes. I certainly have read posts fast and thought they said one thing when in actuality if re-read slower the real meaning comes out.

[GBarnes]

On my rear rotor it appears to be just large head screws that a allen wrench should tighten up. They do not appear to be rivits. There is no way to get at them with out taking the whole rear end out. I will probobly just live with it for now.



Big John,
They may look like screws, but they are rivets.

I'm the guy David was referring to that put the high-temp silicone on the rotor. It worked for about eight months. Considering I rode 6 miles a day on a fairly rough dirt road, I was happy with that time frame. I did it again, but I'm starting to worry that the rivets are getting worn to the point where they may be getting too thin for safety.

I have a second rotor I bought off eBay, but it is a "squealer", so I took it back off. I'm going to take that rotor to a machine shop and see if the rivets an be drilled out and replaced with new expabnsion washers. If they say yes, I'll take my non-squealing rotor in and have it done, (that is, if it's more economical than buying a new rotor).

George

[lnowell]

Big John,
They may look like screws, but they are rivets.

I'm the guy David was referring to that put the high-temp silicone on the rotor. It worked for about eight months. Considering I rode 6 miles a day on a fairly rough dirt road, I was happy with that time frame. I did it again, but I'm starting to worry that the rivets are getting worn to the point where they may be getting too thin for safety.

I have a second rotor I bought off eBay, but it is a "squealer", so I took it back off. I'm going to take that rotor to a machine shop and see if the rivets an be drilled out and replaced with new expabnsion washers. If they say yes, I'll take my non-squealing rotor in and have it done, (that is, if it's more economical than buying a new rotor).

George

I agree with the possible safety issue and used that in my argument with a dealer to replace the rotor - which I do not think he did - only bent the retainer piece to hold the pads close to the rotor. They still rattle (clang) after I corrected the bend in the retainer. It will not get better and I don't think silicone goop is the answer unless you take the rotor assembly off and keep the rotor square with the assembly. I tried to do it to my bike over a year ago and was not able to keep it square - which caused it to act as if it the rotor was warped. I dug it all out and gave up.

[dshealey]

---------I'm the guy David was referring to that put the high-temp silicone on the rotor. It worked for about eight months. ------------
George

Thanks for the update George! I thought that was you, but was not sure. Now we have more data!

[thalpin]

As regards experience with the rear rotor - I have have a 2001 K1200LT with about 134K on it - I am now on my third rear rotor at about $300.00 a pop. This has been a rear rotor about every 45K. Surprisingly (maybe) I use the rear brake very little (got in the habit of staying off of it due to the squealing - which now seems to be mostly cured). Of course, I use it when I need it, but don't make a habit out of being on the rear brake constantly - or otherwise abusing it. My experience has been that, as stated above, the rivets wear and the rotor begins to rattle - really rattle badly. When it gets like that, you can take hold of the rotor and it is very, very lose. This has been the source of quite a bit of disappointment to me in that I have never had any other bike do this (car either). In fact I'm not sure I have ever replaced rotors - front or rear on any other bike I've owned (5 other BMWs for example) though I'm sure they didn't all have "floating rotors."
I'm taking it in tonight to leave it for a Service II and annual. There is some small amount of "rattle" in the rear rotor now - but I will live with this for a while longer.
Just wanted to share my experience with this issue - It is a costly nuisance at best.

[dshealey]

I agree with the possible safety issue -------------.

How do you see it as a safety issue? I think it is certainly a frustrating nuisance due to the noise, but don't think braking is affected in any way. Am I missing something?

[lnowell]

How do you see it as a safety issue? I think it is certainly a frustrating nuisance due to the noise, but don't think braking is affected in any way. Am I missing something?

David, I whish you could see how bad they get. My thoughts (could be wrong) are that when they get real loose, the application of the brakes act like a hammer on the clips. I could actually apply the rear brakes and move the bike forward and back - hearing the click of the brads at each end of the partial rotation. I don't know of any complete failures but it seems the hammering can't be helping at all.

Hope you get another bike soon. I would feel better with you having a reason to stay on this site. You have saved me a lot of money and even more aggravation.

[TUSE]

I will probobly just live with it for now.

I love my LT, but I can not believe we have to use statements like "I will probably just have to live with it!!! This is a BMW for crying out loud!!! And mine clangs (and smokes on start-up [side-stand issues]) like a cheap PoS!!!
And my local dealership just told me... it is suppose to sound like that... Well it has gotten much worse, and I really hope he does not say the same thing now.
This does not sound like BMW Quality to me...

[lnowell]

As an update, a local rider here just replaced his rotor Saturday like I did with the EBC unit. I asked him (Jim from GA) to please take some pictures and post them on this site - which I am not sure will do justice to how bad it was. His was, with out a doubt, a safety issue. I guess mine would have gotten as bad as his had I kept on riding. I fixed mine because I could not stand the sound.

[mjac]

Big John,
They may look like screws, but they are rivets.

I'm the guy David was referring to that put the high-temp silicone on the rotor. It worked for about eight months. Considering I rode 6 miles a day on a fairly rough dirt road, I was happy with that time frame. I did it again, but I'm starting to worry that the rivets are getting worn to the point where they may be getting too thin for safety.

I have a second rotor I bought off eBay, but it is a "squealer", so I took it back off. I'm going to take that rotor to a machine shop and see if the rivets an be drilled out and replaced with new expabnsion washers. If they say yes, I'll take my non-squealing rotor in and have it done, (that is, if it's more economical than buying a new rotor).

George

And I am a guy who followed George's example and did the same at somewhere around 57K miles on my '04 last June. I took some before and after pics too, just so I could look back later at what the difference is/was.
I have since put on over 23K including a 48+ and return to Florida of nearly 13K last May. Yeah, not many miles on the LT since then, butt the FJR has filled the gap :)
For grins I took a look at the LT rotor last night and I wont be changing it any time soon as there has been no noticeable wear. I may redo the high-temp silicone when I get around to it.
Thanks George.
Regards,