Crunch time with my gearbox

[Barry]

As a general rule of thumb, check your tire pressure cold, then ride for 30 minutes or so to get them good and warmed up, and check the pressure again.It should be within 10% of your cold pressure.

As I understand it it is the 10/20 rule.

Because the rear tire does more work than the front it is normal for the front pressure to rise by 10% and the rear to rise by 20%.

I was concerned that pressures of 2.1 bar front and 2.3 bar rear (Manufacturers figures) were not high enough so I did the cold/hot check and got figures very close to the 10/20 rule.

[Semper Gumby]

In fact, there are MANY steel-to-alloy mates on these bikes.  They prefer a soft touch.

...and a torque wrench!!!!  8-)

Which is how SueCanada stripped out those very threads.

Well I wouldn't use a trorque wrench on those tiny bolts (mearly snug as you say) but for everything else YESH!  I don't think a torque is published for the fork drain bolts.  I don't think there is a torque wrench that will go that low -- 6 inch-lbs?

[Rob Valdez 79 R65]

Well I wouldn't use a trorque wrench on those tiny bolts (mearly snug as you say) but for everything else YESH!  I don't think a torque is published for the fork drain bolts.  I don't think there is a torque wrench that will go that low -- 6 inch-lbs?

...and oil pan screws...

For those it is best to use a socket nut screwdriver or a palm-ratchet.

[Matt Chapter]

... I use a 85W140 in the summer...

Bill, Can you detect a noticeable improvement is transmission ops during hot weather while running the 85W140?

Hotlanta and North Texas often share similar temps. Just wondering about warm-up temps for the gear box. Smooth shifts from the git go? I may try your blend.

Monte

YES!  For me it make difference and is worth the effort.

I'm afraid Atlanta doesn't hold a candle to North Texas for hot weather this year.  How many days over 100 have you had?  Makes me wilt just thinking about it.  I would still ride of course....

I wish I'd seen this two weeks ago, I just did my transmission oil and my R65 is my commuter.. in Austin.  Do you use the 85W140 in the final drive and driveshaft too, or just the transmission?

[Semper Gumby]

All three.  In October I change back to 80W90 for the winter months.  Dont Panic (in large friendly letters). No need to change it out.  The 80W90 will work fine this summer.  I use it because it feels better shifting for me.

The really important part is that I change out the gear oils twice a year.  Helps keep the moisture away a from expensive parts and I see potential problems sooner (milky oil/metal bits/grease pushed by the seal in the final drive) by doing this.

[bangpaul]

Very interesting. Do you use a thicker oil in the engine too? Here in Perth, Western Australia, we get consistently hot summers, and I haven't had this bike during one yet.

[bangpaul]

So, to return to the painfully obvious (I always like to check in with you lot before attempting anything) I better replace the oil in the drive shaft. Anything I should look out for? I suppose I just need some crusher washers handy and 150ml of gear oil.

[Rob Valdez 79 R65]

So, to return to the painfully obvious (I always like to check in with you lot before attempting anything) I better replace the oil in the drive shaft. Anything I should look out for? I suppose I just need some crusher washers handy and 150ml of gear oil.

I would do the final drive, as well.  But I've already mentioned that.

Have you changed the engine oil and filter, yet?

[bangpaul]

I haven't done the engine oil since changing the gearbox oil, but it was done recently.

The final drive? Is that like the differential in a car? That's what I was going to change. You mean I need to put oil in the actual shaft as well? How do I get to that? This is starting sound like I'm going to be off the road for a while.

[Rob Valdez 79 R65]

The final drive? Is that like the differential in a car? That's what I was going to change. You mean I need to put oil in the actual shaft as well? How do I get to that?

The drive shaft oil is accessed by a drain and a fill plug in the forward-most part of the alloy casting of the final drive, right behind the black steel swingarm tube that the drive shaft runs in.

These are the plugs that are most easily stripped back there.  Especially the drain plug, because well-meaning but ham-fisted newbies (like me when my bike was new) try to stop this from leaking by tightening it (more).  My dealer at the time was happy to install a Helicoil for me and didn't give me too much grief over it.  This is the space that takes a little less than 150cc of gear lube.

The final drive is sort of like a differential in a car, except there is only one crown wheel, so it does not have any differentiating to do.
Your bike, being an '81 has a different design than my '79, so I might not get it right.
First, a picture of what yours should look like, courtesy of trolle:

There are 3 "ports" on yours -
12 o'clock is a vent that can be removed
9 o'clock is a small plug - I believe the oil level is supposed to come up to the bottom of the threads when that is removed.
6 o'clock - is the drain plug.
Here is your instruction manual, BTW - it is located in our FAQ section:
http://www.bmwr65.org/htdocs/yabbfiles/Attachments/R65OwnersManual_001.pdf
Changing oils in on pages 54-57 of the book, pages 20 & 21 of the PDF.  Read, learn and enjoy!

You can change all three locations in less than an hour.  Ride the bike first and get them warmed up so they drain easily.

If you, personally have not changed the engine oil and filter, you should seriously consider doing so in the near future.
Keep a log book with the dates of the service, mileage and what you did.

When you adjust your valves (have you done that yet?), measure the gap before you adjust them and record those numbers in your log book as well, so you can tell if they are closing up on you faster than normal.

[bangpaul]

Cheers Rob. I appreciate it.

I did replace the oil filter and engine oil myself recently, but I haven't checked the valve gaps. Curiously, the guy who I bought the bike off told me that the few times he checked it they were spot on, and that he never had to adjust them in the 25 years that he owned the bike. Hard to believe, but I suppose I won't know until I try it myself.

[Barry]

Curiously, the guy who I bought the bike off told me that the few times he checked it they were spot on, and that he never had to adjust them in the 25 years that he owned the bike. Hard to believe,

It's almost possible if the bike was very low mileage and he wasn't too fussy to the nearest thou. I've never seen a change of more than half a thou on mine from one year to the next. Having said that you will get some variation just depending on your measurement technique. To get a consistent measurement I like snowbum's recommendation of putting some moderate pressure on the adjuster end of the rocker with your thumb to take up the oil film while checking for a sliding fit with the feeler gauge. If you remove that pressure with your thumb you can actually feel the gauge fit tighten up.

[Semper Gumby]

Very interesting. Do you use a thicker oil in the engine too? Here in Perth, Western Australia, we get consistently hot summers, and I haven't had this bike during one yet.

No.  20W50 during the summer.  Last winter though I did try 10W40 which made the bike easier to start.

[wa1udg]

Probably not going to help BangPaul but I have been running Mobile One 75-90 gear oil in my transmission and shifting is better.  It also helps to be sure the linkage is lubricated with a light grease.  If you are careful you can remove the boot which covers part of the linkage without tearing it up and grease those joints as well.  Won't help the transmission internals but reduces the effort a bit.  Spray Li grease works OK.