A bucket of bolts

[wz31857]

Took a 300 mile ride yesterday to the Buelton antique motorcycle museum and when I pulled in my garage that noise I have been worried about turned into a blender with bolts in it.Removed the transmission this morning and the splines are perfect the clutch hub is perfect.What now? I spin the input shaft and there is about a quarter of a turn before the output shaft moves, is this normal.There is no lateral or horizontal movement of the shaft it shifts nicely through all the gears.No metal in the oil.Should I pull the clutch.Wow 6 months I have owned an rt and the third time I have had the transmission out.One for lube second for rear transmission seal and now.Anybody need a BMW mechanic?

[David R]

Sorry for your loss...

 

 

Did you pull the transmission to fix the drive shaft or final drive?

 

David

[dirtrider]

Afternoon wz31857

 

The noise of " bolts in a blender" doesn't help up much unless it can be placed in prospective.

 

Is it only when moving?

or

Only with clutch lever pulled in?

or

Only with clutch lever out?

or

Only in certain gears?

or

Only in neutral?

or

Only with engine running sitting still?

or

Is it there when coasting engine off?

or

Some other not mentioned

or

A combination of any of the above.

 

We can't hear or feel it over the internet so you have to be our eyes & ears.

 

The more info you give us on EXACTLY when & how the problem shows up the better we can help you identify it.

 

[wz31857]

aT IDLE THERE WAS NOISE IT STOPPED WHEN YOU PULLED IN THE CLUTCH ALL IN NEUTRAL

[wz31857]

NEITHER ,I PULLED IT THIS MORNING EXPECTING SOMETHING OBVIOUS, BUT!

[dirtrider]

Afternoon wz31857

 

 

So we are dealing with a basic neutral gear rattle.

 

Some (maybe all) of that is normal on the BMW boxers as there is basic slack in both the gear mesh & slack in the shifting dogs.

 

Hot thin gear oil & a bit uneven engine idle can make it sound real bad.

 

That wind up in the input shaft before it moves the output shaft is pretty normal due to the gear mesh slack (it goes through multiple gear sets before exiting). As well as the slack in the actual shift slider ears & slots. (lots of internal slop even in a normal BMW boxer gear box)

 

I don't know what to tell you as you already have the trans removed.

 

On the bottom of trans you should find another (2nd) drain plug with a magnet on it. Maybe try removing that to see if there is any abnormal junk on that magnet.

 

Otherwise you can take the trans apart for inspection but bad bearings usually show up as discolored gear oil.

 

[wz31857]

THIS SOUND HAS PROGRESSIVELY WORSENED AS THE MILES STACKED UP,PROBABLY MAYBE A THOUSAND MILES FROM NO SOUND TO I CAN IN NO WAY RIDE IT ANY LONGER WITH A RATTLE LIKE THAT.THE SECOND DRAIN PLUG YOU REFER TO IS THE MUCH LARGER ONE ON THE VERY BOTTOM?I SURE HATE TO DISSASEMBLE THE TRANSMISSION AND FIND OUT IT'S CLUTCH RELATED

[OoPEZoO]

Dude.....turn the CAPS lock off. It hurts my brain

[dirtrider]

Afternoon wz31857

 

There is basically only one on the bottom of the trans main case but yes it is a bit larger.

 

That noise getting louder the more you ride it could still be normal as the gear oil shears during use so ends up getting thinner. Thinner gear oil means more pronounced neutral gear rattle.

Same with the engine running a bit rougher at idle, the harsher the engine firing pulses at idle the noisier the trans usually is in neutral w/ hot trans.

 

 

IF, your noise is only in neutral but not while riding that tells you something right there as a trans noise due to something internally wrong as rule doesn't only show up in neutral.

 

Unfortunately you have it apart already so you have lost the ability of trying new thicker ( Re. Red Line Heavy) or trying to raise the engine idle RPM slightly. That will probably mean that if you are still really worried about that noise you will probably have to take the clutch & trans apart as well as inspect the slave cylinder bearing to eliminate those as problem areas.

 

[wz31857]

I do sincerely appreciate your input but this is a sound that I guarantee you would stop you from leaving the garage.

[dirtrider]

Afternoon wz31857

 

Well start with the easy things to check like the slave cylinder bearing & for engine crankshaft end play (push/pull on the flywheel).

 

Maybe look for a loose spring plate in the clutch.

 

[wz31857]

The slave cylinder is new ,I don't see any visible damage or cracks in the clutch of course I have not disassembled it yet.

[Galactic Greyhound]

The slave cylinder is new ,I don't see any visible damage or cracks in the clutch of course I have not disassembled it yet.

 

While the transmission is off -

Take both spark plugs out and turn over the engine slowly a couple of times using the flywheel ring gear - watch/listen around the flywheel/clutch for anything loose. Check the surrounding engine casing for any tell-tale marking.

 

Also check for any up/down movement on the crankshaft/flywheel.

[Caleab]

does this video depict a similar sound?

 

 

 

[wz31857]

Thank God no.As a matter of fact I have the transmission out and the splines and clutch are perfect.Personally I think it's the input shaft spring cluster.I do commercial air conditioning and right now the days are long,but I have lined up an RTP transmission from a kid who needs help removing it from the engine and disassembling the drive line components.I am curious to see if his has the quarter turn of freeplay on the input shaft before the output shaft moves.

[David R]

There should be some free play in the transmission. Are you sure its not the driveshaft splines?

 

David

[Joe Frickin' Friday]

Thank God no.As a matter of fact I have the transmission out and the splines and clutch are perfect.Personally I think it's the input shaft spring cluster.

 

Is there axial play in the input shaft? That is, can you push/pull the input shaft into/out of the gearbox by any significant distance?

[wz31857]

Theres absolutely 0 movement in the input shaft except that you rotate the input shaft in gear and it requires a quarter turn before the ouput shaft moves.I don't have any movement up or down on the crank and only thousands in and out. Rotating the crank did not reveal any clues either.