R60/5 - Transmission

[leswaller]

I have just completed the first decent run (50 miles) since I breathed life in the '72 R60/5 that I bought as almost a basket case. Everything looks and feels great and I easily got and sustained over 80 mph out of the old girl on a flat road without trying, which considering that I weigh more than 230 lbs, is like riding two up all the time.
The two questions I have, as I am new to BMWs, are these;
1. When pulling away from a standing start there is a slight transmission whine (worse when the engine is cold) in 1st and 2nd gears. Is this acceptable, and if not then what is the likely cause and solution.
2. I have the usual clunk when engaging 1st and 2nd, but also occasionally get a second clunk when releasing the clutch as if something has stuck and then releases. What is this likely to be, will it sort itself out, should I live with it, or does it need urgent attention
Many thanks for your expert help
Les

[tvrla]

Les - I'm not all that familiar with /5s, but don't think you have anything to worry about. I would monitor the trans drain plug watching for more than just fuzz on the magnet - they have magnets on the /5, don't they?

Some of the bearings may have gotten a little rusty if it sat for very long. It's open to atmosphere, the oil eventually drains off of everything, and moisture begins its task of corroding all it contacts. Hopefully any corrosion in there is minor. But do monitor the oil.

There is a lot of play in the gears when they're mated up (more specifically, the dogs and their respective mating recesses) and you can feel it with the bike in gear on the center stand rotating the rear wheel.

Those R60/5s are amazingly powerful for their size, aren't they?

[Barry]

Going up hill under load mine whines little in the lower gears and has done that from very low mileage. I think that would be normal as only top has helical cut gears. Straight cut gears can tend to whine a little.

The 2nd clunk is more of a concern. I would put the box in neutral and rotate the rear wheel to check for smoothness and excessive slack

[Bob_Roller]

The second clunk, are the transmission splines lubed, sorry to ask such a question, as it's common knowledge to lube the splines .

I like to back to the simplest explanation, after heavy maintenance has been performed .

Throwout bearing at the back of the transmission lubed ?

Clutch cable not hanging up ?

Drive shaft/u-joint bolts tight ?

Just thinking off the top of my head !!!!

[badbmwbrad]

Slash 5's are really cool looking bikes; especially with the big touring tank.  Mine is a model R75/5.  The engine makes good, usable torque from low RPM right up through 5500 - 6000 RPM.  The R60/5 is said to have the best tick-over.  

My 4-speed transmission does make a whine noise; especially in 1st and 2nd gear.  I added some Dow Corning M gear oil additive (molybdenum disulfide) to the trans/shaft & bevel drive oil reservoirs.  Only a very small amount ~3% is needed.  This makes the transmission run longer and perhaps quieter.  Oak Oakleshen recommends it for use in Airhead trans/shaft & bevel drive oil (but not with synthetic oil).
http://www.dowcorning.com/applications/search/default.aspx?R=28EN

I agree the second clunk could be the rear wheel splines.  Clean the drive splines and wheel hub splines.  Paste the wheel hub splines with Honda Moly 60 grease.  Avoid pushing any grime into the drive spline's ring gear seal area when cleaning.

Worn rear wheel splines can make a clunk when taking off from a stop (after using the rear brake) or if you slow down with rear brake then accelerate.  When stopped, back up just a bit to take up any free play between the drive spline and hub spline.

If you are traveling slow and find using the rear brake (then accelerating) produces the clunk noise then simply avoid using the rear brake (use front brake instead) under these conditions.

A new wheel hub spline is $110 and new rivets are cheap enough.  The trick to rear hub spline replacement is to carefully remove the rivet heads and drill out most of the rivet before carefully tapping it out of the rear wheel hub.   The rivets have to be bucked up then a hollow-ended drift is used to peen and expand the rivets.  The rivet diameter has to expand and fill the hole tightly so there's no free play.  Tom Cutter said he uses one of the transmission shafts for a punch tool because the shaft end is hollowed out.
http://www.bigflatsrivet.com/tools.html

I breathed life in the '72 R60/5 that I bought as almost a basket case. Everything looks and feels great and I easily got and sustained over 80 mph out of the old girl on a flat road without trying, which considering that I weigh more than 230 lbs, is like riding two up all the time.

The two questions I have, as I am new to BMWs, are these;
1. When pulling away from a standing start there is a slight transmission whine (worse when the engine is cold) in 1st and 2nd gears. Is this acceptable, and if not then what is the likely cause and solution.
2. I have the usual clunk when engaging 1st and 2nd, but also occasionally get a second clunk when releasing the clutch as if something has stuck and then releases. What is this likely to be, will it sort itself out, should I live with it, or does it need urgent attention
Many thanks for your expert help
Les

[leswaller]

Thanks Guys, that is reassuring about the whine, I will try a little additive. When I got the bike (which had been stood for more than two years) the speedo drive rubber boot was missing and when I drained the gearbox oil it was obvious that some water had got in as the oil had started to emulsify. I drained and flushed the gearbox and checked the drain plug for bits (it was clean). So I am hoping that the whine is just surface rust and will clear. I feel that the second clunk might be something to do with the clutch as I can feel it through the clutch cable (which is new). It is getting better  and is only when pulling away so may be just something sticking. I did pull off the rear wheel to check the splines when I first got the bike and they seem ok. I smeared copper grease on them before reassembling. Hope this is ok There is no clunking when checking by rotating the wheel in gear on the center stand
As you say, a really great ride with plenty of power, I can feel the flywheel torque/giro effect at low speeds which is quite strange until you realise what it is.
Les

[Dizerens5]

I had a 60/5 from new in 1971 (my first brand-new bike). I well remember the second clunk, but it was only slight. That bike had it from new, it never went away, it never got worse in 3 years. I never found the cause. When I tried to invoke the guarantee I just got told not to worry. That turned out correct.