Vibration in Gearbox

[ToNCfromNM]

Hi All-

 

I have a '96 R1100RS with 42K miles. Lately, when the engine is cold, I feel a dull vibration in the gearbox when shifting from first to second or downshifting from second to first. As the engine warms-up the vibration is less noticeable. Shifting through is the gears is fine.

 

I've changed the gearbox oil recently and found no signs of metal on the drainplug.

 

Is this anything to be concerned about?

 

Thanks in advance for you help.

[T__]

ToNCfromNM, sure it is something to be concerned about if it wasn’t there before but is now..

 

It might be nothing more than a cupped tire or just a engine roughness at throttle drop during gear change but we can’t feel or hear the vibration from here so can’t tell you anything definitive.. ..

 

We need LOTS more info from you on the vibration,, type,, frequency,, when it started,, where you feel it,, where you hear it,, is it engine speed related,, or wheel speed related,, or drive shaft speed related..

 

The more info you can furnish the more we can help you..

 

Play with different shift speeds,, different engine RPM’s during the shift,, coast it down a hill with engine off, etc.. You will need to do a little playing then see if you can give us more info..

 

Or have your local dealer tec take if for a ride..

 

 

Twisty

 

[ToNCfromNM]

Thanks Twisty for the rapid response.

 

The dull vibration I feel occurs under deceleration when shifting from second to first or if I accelerate in low gear (first or second), pull the clutch and "drift", I feel a vibration. The exact location where this is coming from is difficult, so it could be engine, gearbox, clutch or FD?

 

I've tried to simulate this with the bike on it's centerstand, but could not reproduce the vibration I feel when the bike is moving. So this implies to me that a "load" needs to be present to initiate the vibration.

 

My tires are in good shape (no cupping).

 

I'll continue to get as much info on this as I can and post back.

[ToNCfromNM]

OK all, I stand corrected.

 

The vibration I feel is coming from the tires when I swerve back and forth. It takes about 20mph to initiate the feel. I was able to reproduce it with the engine off (coasting) and engine on with clutch engaged.

 

I have ~1000miles on my Michelin Pilot Road 2's. They don't appear cupped. I run 36psi front and 39psi rear because my wife is often times a passenger.

 

What next?

 

 

[AndyS]

OK all, I stand corrected.

 

The vibration I feel is coming from the tires when I swerve back and forth. It takes about 20mph to initiate the feel. I was able to reproduce it with the engine off (coasting) and engine on with clutch engaged.

 

I have ~1000miles on my Michelin Pilot Road 2's. They don't appear cupped. I run 36psi front and 39psi rear because my wife is often times a passenger.

 

What next?

 

 

Unfortunately you have to make a choice I see 4 options but other folk may see more.

Option 3 & 4 are a tad on the extreme!

 

1/. Live with it. These Pilot Road 2's are the noisiest most uncomfortable tyres I have ever used (but they do stick well). I will not replace mine with the same make when the time comes.

 

2/. Bite the bullet, live with the cost and get rid of the tyres. Buy some new ones of a different make.....I am not even going to hint a a suggestion of what brand to choose - 'cos we all know what happens with tyre threads!

 

3/. Don't ride the bike

 

4/.Get rid of the bike.

 

 

Andy

[Jerry Duke]

You say you recently changed the gear oil. Did you change weight or brand?

[ToNCfromNM]

Hi Jerry,

 

I use Sta-Lube hypoid 80W-90 GL5 gear oil.

 

As I mentioned in my previous post, the vibration is coming from the tires. I'll put up with the slight annoyance over new tire purchase for now.

[tazplas]

I reckon your on to it with the tyre diagnostic.

 

Then again, may still pay to check for other issues such as vibration from the gearbox if you think that is a problem.

 

Anyhow, I never had vibration probs until i had PR2's fitted. Only occurs during corners and when not powering through (coasting). These tyres also seem to howl. I have about 9000km (just over 5000 miles) on them. Apart from that, they're great in the wet and dry.

 

Cheers

 

Steve

 

 

[duketr4]

WOW, I cant believe I read this information.

 

Over the last few months i too have been suffering from this strange vibration as i swerve side to side....I had came to the conclusion that the main bearing in the FD was on it's way out so i proceeded to change the 2 bearings on the crown wheel.

 

Much to my disappointment when i jumped on the bike that nasty vibration was still there as i went side to side....my first reaction was "what now".

 

I've been scratching my head for the last 3 weeks trying to figure the problem & my thoughts were focusing on the tail shaft & likely the uni joints. It had become so mind consuming that i would be constantly anticipating at what point the situation would become ugly.

 

I now go home tonight a happy man knowing that my Pilot Road 2's are in fact the problem & my tail shaft is OK.

 

It pays to read the threads.....thank you all.

[AndyS]

...suffering from this strange vibration as i swerve side to side....Iso i proceeded to change the 2 bearings on the crown wheel.

 

Have you actually replaced the bearings yet(on the FD?).

If so, are you absolutely sure everything is shimmed and preloaded as it should be?

 

I am worried that you may well have just engineered in a potential failure.

 

If the answer is yes (you have just done it), and have not set it up exactly right, then I recommend you seek the guidance of others on this site (Anton Twisty / Boffin and many others). It may be time to get the FD re-repaired or it may cost you big bucks.

 

Andy

[Anton Largiader]

I'm surprised at the comments on the PR2s. My customers are delighted with them and no one has mentioned noise or vibration issues.

[T__]

Anton, it might have a lot to do with the road surfaces being ridden on.. The PR2’s go noisy on me at fairly low miles with a defined roar as I lean the bike over or side to side.. Our road surfaces up here are fairly coarse,, also on some of the hi-ways they are doing a high traction surface..

 

Traffic also moves along pretty fast up here with free-way speeds moving along at mid to upper 80’s & surface roads averaging about 10-15 over the limit.. Not sure that matters but it can’t help tire wear..

 

Twisty

 

[NonComp]

I have the same problem with an ME880 on the back. Anything off vertical gets it howling and thrumbing. It's worse at some speeds than others.

[DavidEBSmith]

The vibration I feel is coming from the tires when I swerve back and forth. It takes about 20mph to initiate the feel. I was able to reproduce it with the engine off (coasting) and engine on with clutch engaged.

 

I have the same thing happening, also with PR2s. Fortunately I just ignore strange vibrations until something breaks. It's much easier to diagnose that way.

 

[ToNCfromNM]

Andy,

 

I understand your concern for potential FD or pivot bearing issues, but I find it very interesting that there are so many posts describing the PR2's and vibration. In fact, Search "Michelin Pilot Road 2's" or this thread for that matter, to see how many people discuss this issue.

 

If you suspect a pivot or rear bearing issue, there is an easy test. Raise the bike on the centerstand and try to wiggle the rear wheel at 6 and 12 o'clock and 3 and 9 o'clock. If you feel movement (ensure it's not coming from the rear shock), have an assistant (wife, son, etc...) depress the rear brake. If the movement goes away, it's the FD bearing. If not, it's the pivot bearing.

 

Cheers.

[duketr4]

Andy

 

In response to your post the FD crown bearings have been changed & shimmed accordingly. I could of done more miles on the original bearings but the bike had 135K clocked up so I was comfortable having to replace the bearings rather than wait for a failure. I also changed the para lever bearing while i was there.

 

I was convinced this dull vibration was due to the large crown wheel bearing being at the end of it's life as some threads on this forum indicated.

 

I had not previously used PR2's nor imagined a tire could display these type of symptoms.

 

Despite the PR's being a good tire, I'll head back to Bridgestones 020's when these tire are done. I should point out the tires started to display this dull vibration after about 4000Km of usage.

 

John

[AndyS]

Andy

 

In response to your post the FD crown bearings have been changed & shimmed accordingly.....

John

 

Hi John,

Thanks for responding. My concern was not that you had replaced the bearings, but that you replaced them without going through the correct pre-load and shimming checks.

This repair has been carried out by many folk who have accidentally assumed that the bearing they buy in, will be exactly the same as the one they took out so just put the new bearings in and button the FD back up. Many folk have not had the equipment to check relevant pre-load and shimming routines. So, shortly after the initial repair an expensive repair is needed again.

Cheers.

Andy