R100 gearbox rattle
Bronwen Williams
kms?
Happens in neutral with the clutch released. Suspect it is a bearing.
Does it continue to rattle without problems?
Does it need fixing?
What is involved?
--
Steve Williams
Melbourne, Australia
James Clark
The Older Gentleman wrote:
> Bronwen Williams <bronwen...@optushome.com.au> wrote:
>
> > Can anyone help with advice about a gearbox rattle from a 1993 R100 28,000
> > kms?
> >
> > Happens in neutral with the clutch released. Suspect it is a bearing.
>
> Yup. had the same thing happen to me. Errrr.... can't remember which one
> it was. Might have been the clutch support bearing.
> >
> > Does it continue to rattle without problems?
>
> For quite some time, yes, in my case.
>
> > Does it need fixing?
> > What is involved?
> >
> Can't remember, but the sum of ukp200 comes to mind. It was a while ago.
>
Rather than worry about rattling noises when the engine is idling,
wouldn't it be better to disengage the clutch and turn the rear wheel
by hand (while in gear), listening for grinding noises?
Even brand new, BMWs tend to rattle the gears quite a bit at idle.
And the transmission case functions a bit like a drum, which does little
to damp the noise.
Two things that can extend the life of the gearbox is to avoid lugging
the engine and avoid using the engine for braking The helical gear on
the end of the input shaft tends to take out these abuses on the bearing
at the back of the gearbox. (ISTR the front bearing being a needle
bearing, but I'd have to check on that.) I do know that these end loads
from the helical gear were addressed on the Ks by supporting the
the input shaft with matched tapered roller bearings.
- Philip
>kms?
>
> Happens in neutral with the clutch released. Suspect it is a bearing.
>
It's NORMAL. Supposing you have 90wt hypoid oil and have ridden the bike at
least 30-40 miles. Sitting with the trans in neutral, clutch released, it is
normal to hear the input shaft bearings making a rolling rattle. The thinner
the oil (or hotter the the transmission) coupled with a poorly tuned engine
(rough idle) will just exacerbate the noise. It hurts nothing. Furthermore,
you will find later BMW's and similar dry clutch motorcycles (ie, Moto Guzzi)
exhibiting the same tendency.
-Philip-
"Character is like a tree and reputation a shadow.
The shadow is what we think of it; the tree is the real thing."
- Abraham Lincoln
Flash - DoD #412
> Can anyone help with advice about a gearbox rattle from a 1993 R100 28,000
> kms? Happens in neutral with the clutch released. Suspect it is a bearing.
>
> Does it continue to rattle without problems?
> Does it need fixing?
> What is involved?
Loosen the driveshaft bolts. Remove the battery and battery box. Remove the
swingarm bolts. Remove the drive shaft bolts. Remove the left carb and both
carb elbows. Remove the airbox. Remove the clutch arm from the back of the
gearbox. Remove the trans mounting bolts. Have someone pull the rear wheel
(and swingarm) back away from the trans while you slip the trans back away
from the motor some. CAREFULLY remove the neutral switch wires. Take the
trans out the left side of the bike.
If it isn't the throwout bearing, which it probably isn't, take the gearbox to
your dealer.
- Flash - DoD #412
- http://www.deathstar.org/~flash for Tales of Adventure (and wrenching)
James Clark
Why would you need to pull the gearbox to check the thowout bearing?
It sits right under the clutch arm at the back of the gearbox.
Old Biker
IMHO this as a common problem with 81+ Airheads. If it quiets
down with just a bit of pressure on the lever it's most likely
the clutch release (throwout) bearing has a bit of excess play.
I owned two like that and put tens of 1000s of miles on them
with no trouble.
Flash - DoD #412
Because you can't pull the throwout bearing back far enough to get it out without
first moving the gearbox. There is a rather small frame cross-member in the way.
- Flash