Awful noise from transmisson (I think)

[ColumbiaBMW]

While riding around town today and pulling away from an intersection when I shifted into 3rd gear it found a false neutral, I have really worked on my shifting and hardly ever find a false neutral anymore, especially when going into third. But here I was rolling along at probably 35 (wild guess) and in neutral, so I tried kicking it up again after scrubbing off some speed and it wouldn't go into 3rd (and made the awful gears grinding noise), so I kicked it down into 2nd and all seemed to be fine.

I noticed though that at the next stoplight, it was making a weird sort of knocking noise.

I rode it straight home and when I got it into my garage let it idle while crawling around the bike listening for the sound. It wasn't making the sound of course so while it was idling in neutral I gently revved the engine and then it appeared. It seems to be coming from the transmission but why would a sound be coming from the transmission if it was in neutral? It is a terrible grinding/knocking sound, but I am 95% it isn't coming from either cylinder, and it is definetly on the right side.

Please tell me my miss shifting didn't cause my worst nightmare (spline failure). I have no idea what I'm going to do though, I had a big trip to Colorado planned in a few weeks and if it's something big I'll just have to cancel I guess.

Anybody have any ideas? I would greatly appreciate any input!!

[ColumbiaBMW]

By the way, I was just fooling around with it again trying to figure out what it is and I discovered that if I pull in the clutch, it goes away completely. So anyone know what is going on? Thanks again.

[KHaynes]

You're assuming that the damage is related to your mis-shift; it may be unrelated but it's likely that it is.
It's unlikely that it's a spline failure if you can clearly hear it on one side of the bike.
My concern is the knocking. This kind of hints a broken gear tooth.
I hope I'm wrong but it could be worse than you first expected.
I wish I could take a more optimistic view on this. Maybe someone else will offer you some hope.

I'd start by draining the gear oil and looking for metal particles.

[iowabeakster]

I am not gonna tell you what I think it is. The big hint is the knocking and grinding goes away when the clutch is pulled in. Like Keith said, it could be the tranny. I have heard of people whose bearings in the tranny have failed. Not an easy fix with that problem either.

I will say, that I don't believe your mis-shift caused the problem. The mis-shift happened because there is a problem.

You say that you quickly rode home. Good move.

How did the bike act/sound on the way home? How was the shifting? What gears did you use? What gears sound better/worse or all the same? Does the sound get worse as you apply more power?

I am really sorry to hear this.

[ColumbiaBMW]

I didn't hear anything unusual while riding around after the mis-shift, it seems to only be making these noises at idle. Maybe I just can't hear it while moving though due to all the wind and engine noise. I'm pretty sure it goes away though after it's in gear and I'm moving. And like I said before the noise goes away as soon as I pull the clutch in, it's just in neutral it makes this awful sound.

[ColumbiaBMW]

I just called the shop here in town and will be dropping my bike off later today to have them take a look at it. It's not a BMW shop but one guy that works there races BMW's and knows pretty much everything about them, so I feel confident it will be repaired correctly. Now for a little game of The Price is Right, anybody want to guess what it will cost? I'll start, I predict it will be $1,850.

PS I will keep you all updated and let you know what went wrong, if I fix this though, and then a few thousand miles down the road have another huge problem, I'll have a cheap 2003 R1150R for sale, that's for sure.

[reef]

Hi Ihad same thing going on a month ago.It was slave clutch cylinder failure.I would check color of your fluid in reservoar,also clutch feels little bid mushy.but i didnt notice till i touch some other clutch and find that is supposed feel much harder.I know it is strange but true.In service they had no idea what cause noise.bud friend directed me to that problem and bingo.Service ask around $ 400 to fix it,but I pay $ 120 for parts and did around 4 hours of labor ano comlications,Thanks to Touchton and his wisdom. Good luck Mark ps.call me if you need more info 615/715 9433

[ColumbiaBMW]

Well I took it to the shop today after work and it didn't make the sound at all anymore, of course....

The guy at the shop told me that I was probably just hearing the dry clutch rattle, but it has never been this loud. He showed me how to take the starter off to get to the clutch to take a look and I may try that later, but I had to have him put on a new front tire anyway so I asked him to ride it around and let me know if he hears anything unusual. He owns BMW's (he just recently traded a Boxercup replica away) so he would definetly know if anything is wrong. I've never hoped so badly that I was wrong about something in my life, if he's right and it really is nothing that means quite a bit of $$$ will be staying with me. (For now...the wedding is about a month away now...)

[KHaynes]

Many of the Boxer transmissions do make some noise - mine included. It is the rattling of the gears within the transmission caused by gear lash. If that is the problem then the typical beahviour is this:
1. There will be no noise when the transmission is cold and the oil is thick.
2. It will only make the noise when fully warmed up - but not always.
3. The sound is a non-rhythmic rattling or chattering that will go away when the clutch is fully pulled in - hence stopping the gears from turning.
4. The sound will never be there while riding and under any load.
The noise can be eliminated by changing to a thicker oil but if the only problem is the "sound" it makes, there is not a problem at all.

If you have a gear tooth missing, the sound will be rhythmic and in sympathy with engine rpm. It will be more pronounced when riding and under load in the particular gear that is broken.
I hope that you only described the common gear rattle.

Don't forget to tell us of your findings.

[ColumbiaBMW]

Well thanks again to everyone for their advice and input, but the guy at the shop says nothing is wrong, he even took it for a test ride to make sure everything was working alright. (I'm just confused because I know I never heard this rattle before, even my girlfriend said it sounded terrible.) I had the shop change the transmission oil and final drive oil for me since I already had the bike in for a new front tire, and he just called this morning to tell me it was all done and ready to be picked up. Maybe the transmission was just low on oil, or just really needed an oil change (I know the oil in the trans and final drive has never been changed, and the bike is now at 19,500 miles). Who knows, hopefully all is well now. Thanks again.

[sweatmark]

Columbia - Any update on your bike's drivetrain noises? Inquiring minds want to know (and hope the problem's gone away for you).

[ColumbiaBMW]

Well I took the bike in to the shop for a new front tire, and he said that he would just change the transmission oil and final drive oil, then drive it around to see how it sounded. He said he never heard anything (it still does it occasionally), but he said that sometimes these BMW's transmissions do make weird noises due to "drive lash".

This guy has been working on BMW's longer than I've been alive so think it's safe to assume that when he changed the transmission oil he was looking for shavings, and he never mentioned anything about the oil being in bad shape so it must have been ok. I've been riding it all week to work again and it will at least once or twice a day make this knocking noise when I pull up to an intersection, but will go away if I blip the throttle. It is working fine, and shifting fine, I just don't know why it would go from not making this noise the last 5,000 miles I have owned the bike, to suddenly making this noise daily.

I still plan on taking it to Colorado this summer, so I will let you know how the transmission holds up on that trip. So is this normal though, for my bike to occasionally make a loud knocking noise? Is it another one of those, "they all do that" kind of things? Maybe I will try to get the sound recorded and put on YouTube, then you can all hear what I am talking about, and tell me whether I am an idiot and it's nothing, or if I should take it somewhere else for a second opinion.