The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: bangpaul on August 03, 2011, 03:43:22 AM
-
This slipping into neutral problem is getting worse. It seems to happen more often when I'm going down the gears, which is dangerous because I'm relying on the gears to help with braking. Gear changes seem to be getting crunchier too.
I found the filler hole, and the level seems fine, but the oil is that milky-brown iced-coffee colour. Viscosity doesn't seem too bad, I suppose, although I've never encountered gearbox oil before.
I'm getting a bit concerned. Any advice? I was going to just replace the oil and hope things improve. Seems like the only option within my capabilities.
Any tips for the oil change? First time I've done it but I can't imagine it's much different to changing the engine oil.
Thanks, as always.
-
Changing the oil is very straightforward. Same principle as changing engine oil - do it hot and leave to drain well.
By your description of the colour it sounds like you might have water in the oil. It can get in past the speedo drive rubber boot which may need replacement or better sealing. With regular maintenance and a sound gearbox, gear oil should always look much the same colour when you drain it out as when you put it in. Having said that you are always going to find some fuzz on the magnetic drain plug. If it feels like smooth grey paste then that's normal. Any gritty fragments or slivers of metal suggests a problem needing investigation. If the oil is a really bad colour you might consider a 2nd oil change soon after to make sure all the crap has been flushed out.
Slipping into neutral can indicate gearbox problems. There was a gear selector modification kit available back in the day but it's no longer available and the parts needed to make it up now amount to such serious money you might be better going for an exchange or 2nd hand gearbox. Before condemning your box though make sure after the oil change that you are using appropriate shifting techniques. Lightly pre-load the shift lever before pulling in the clutch and the change will be easier and make sure to follow through till the shift lever hit it 's stop.
-
Thanks Barry. You've got a knack for explaining things well to people who don't have much experience with these things. I hope your career made use of your teaching skills. I do have a couple of further questions though.
The speedo drive rubber boot is the rubber cap thing that's at the top of the gearbox on the right hand side where a cable goes in right? If so, this is old and cracked and could very well be allowing water in.
The big rubber boot on the driveshaft is also worn and needs replacing. It seems to be leaking a bit. Has anyone ever tried shoo goo as a temporary measure? I'm not up to dismantling the rear end yet.
Also, I may have not expressed myself very well when I described it as "slipping into neutral." The bike doesn't slip out of gear into neutral. I seem to get it into gear, the shift lever hitting it's stop, but when I let the clutch out I find I'm in neutral. But I'll try the technique you mentioned as I haven't heard or tried that before.
Lastly, what sort of gear oil is best for these old bikes? Is there much difference between them?
Thanks again. I'd never have the confidence to attempt these things without this site. It's becoming a real education.
I'm starting to get the impression this bike wasn't as well maintained as I was lead to believe. But it might just be it's been used continuously, and the harsh sun here would be pretty unforgiving on those rubber parts.
-
The speedo drive rubber boot is the rubber cap thing that's at the top of the gearbox on the right hand side where a cable goes in right? If so, this is old and cracked and could very well be allowing water in.
Yes that's it. Mine was old and cracked and didn't seal well around the cable so had to be replaced.
The big rubber boot on the driveshaft is also worn and needs replacing. It seems to be leaking a bit. Has anyone ever tried shoo goo as a temporary measure? I'm not up to dismantling the rear end yet.
Unless the boot is actually split you maybe abe to adjust the clamp to re-seal it. Fiddly job though.
he bike doesn't slip out of gear into neutral. I seem to get it into gear, the shift lever hitting it's stop, but when I let the clutch out I find I'm in neutral. But I'll try the technique you mentioned as I haven't heard or tried that before.
This technique is not my idea. It's a commonly used method mentioned on all the Airheads forums. Finding the odd neutral between gears is not unheard of but shouldn't be a common experience.
Lastly, what sort of gear oil is best for these old bikes? Is there much difference between them?
Any decent 80W/90 gear oil to GL4 or GL5 spec will be fine.
-
Thanks again Barry.
The boot is actually split it seems. Or it has lots of little splits. Seems like quite a task replacing it. Do you think a polyurethane-based adhesive would work alright for a while? As long as I gave it a good clean of course. Far from ideal I know.
-
It's a quite easy job to replace the rubber boot, remove the speedometer cable from the transmission, remove the old boot, lube the new boot, install it over the end of the cable .
Believe it or not, the boot goes over the fitting at the end of the cable, doesn't look like it should, but it does .
-
Sorry Bob. Probably didn't make it clear that we'd veered off the topic and begun talking about the big driveshaft boot. That's the one I'm thinking of shoe gooing.
The other one doesn't look to hard, but I'm sure I'll manage to complicate things. As long as the parts guy has one on hand....
-
Replacing the speedometer boot is no biggie. A little oil or silicone lube will assist the boot over the speedo drive.
Do Not strip the threads in the gearbox case by over-torquing the bolt securing both the battery negative cable terminal and the speedometer drive! Just snug it up with a short wrench.
The driveshaft boot replacement is much more complicated.
Besides a new boot- which has a "top and bottom" installation position- you will need new driveshaft U-joint attach bolts to refit after going through the swingarm removal and transmission detach. The correct BMW bolts are now shorter than the OEMs and do not utilize lock washers.
As the swingarm will be loose, you may as well use this opportunity to clean, inspect and re-grease the swingarm tapered roller bearings. A transmission spline lube would also be in order.
Do you have either a Clymer or Haynes shop manual? Will be very helpful should you consider undertaking the driveshaft boot replacement chore. All straight forward but often fiddly.
The driveshaft boot will flex with every movement of the rear suspension; I would not place any large bets on the success of trying to use an adhesive to "fix" splits.
Charlie Mike. Let us know what you need by way of assistance.
Monte
-
Any tips for the oil change? First time I've done it but I can't imagine it's much different to changing the engine oil.
Thanks, as always.
I just did my transmission oil for the first time and would really, really have liked to use a 19 mm socket to undo the drain bolt, instead of trying to use the box wrench in the standard toolkit. Next time I'll have one for sure.
-
A 19mm socket has many uses on these bikes. (engine mounts, for one other).
Replacing the swing-arm boot can be frustrating for anyone, especially so for a first timer.
Get all your cuss-words lined up beforehand. A new boot does not have the flexibility that re-installing the old one would have.
I created a hook tool for this job by taking a small screwdriver and heating the tip cherry red and bending it 90°.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.pbase.com%2Ftomfarr%2Fimage%2F123172823%2Fmedium.jpg&hash=01644fd4db3ab61ba489665262e959f1d85d564a)
-
... I created a hook tool for this job by taking a small screwdriver and heating the tip cherry red and bending it 90°.
Now you share this little gem of wisdom. I'm going to make up my own bendy screwdriver just so I'll have one for "next time".
I think I tore off three fingernails getting that freakin" boot fitted. [smiley=wall.gif]
Monte
-
... I created a hook tool for this job by taking a small screwdriver and heating the tip cherry red and bending it 90°.
Now you share this little gem of wisdom. I'm going to make up my own bendy screwdriver just so I'll have one for "next time".
I think I tore off three fingernails getting that freakin" boot fitted. [smiley=wall.gif]
Monte
Trust me - the special tool only makes you think the job is going to go easier.
-
And some of the boots are marked with both a "upper" (ober).
Look closely, you should see that one end of the boot is "squarish" and the other end round.
According to this guy's blog, the square end attached to the swing-arm and the round end attaches to the gearbox. http://type247.wordpress.com/page/2/
-
It's a quite easy job to replace the rubber boot, remove the speedometer cable from the transmission,
Let's start with the basics then: how do I get the speedo cable detached from the gearbox?
-
It's a quite easy job to replace the rubber boot, remove the speedometer cable from the transmission,
Let's start with the basics then: how do I get the speedo cable detached from the gearbox?
Remove the small bolt on the trans box just below the rubber bootie. 10mm wrench req'd.
Withdraw the bolt.
Withdraw speedometer cable. Done, done and done.
Look closely at the bolt. It is rifle drilled, ie: hollow in the longitudinal axis. It is a vent for the transmission. Make sure it's clear.
Exercise caution when refitting the bolt. DO NOT over tighten and strip the threads in the gearbox case! Just snug it up and be happy.
Monte
-
If you're having trouble down-shifting it could be your technique or the transmission input splines need to be lubed. The clutch needs to slide on those splines or it won't disengage properly.
Also, considering the expense and fragility of these transmissions (it's a weak link) it's best to use the brakes to slow down. If you're that much in a hurry (or into racing) this isn't the bike for you. If the brakes aren't doing their job, then that needs looking into.
-
Well, the oil change has done wonders, but you could be right: I think my shifting technique could do with some refining. I am still getting used to the bike.
As for not using the gears for slowing down, I'm pretty surprised to hear you consider that racing, I thought that was just part of riding. I would've thought the transmission was built for it, but I am pretty new to motorbikes. I tend to use the brakes in unison, and apart from some squealing they're fine for what they are.
-
I use engine braking all the time to slow down but not always by changing down a gear. I find a motorcycle without some engine braking effect is tiresome to ride. Single cylinders are best and multi's the worst in this respect. Airheads seem to have a useful amount of engine braking.
Changing down smoothly on an airhead is easy enough when you are pressing on and using enough revs to blip the throttle. Not so smooth and easy at low revs when you are trundling along in traffic.
Bottom line is anyone new to an airhead is not going to rate the gearchange as it's best feature but you do get used to it in time.
-
Beemer brakes are much more economical to replace than transmissions. [smiley=thumbsup.gif]
For me, stirring the Airhead gearbox required I practice but three simple skills:
1. Practice
2. Practice
3. Practice
Develop items 1 thru 3, along with the secondary skills of matching engine rpm to gear speed, pre-loading the shift lever, keeping the transmission splines cleaned and lubed, gear lube clean and at correct level, shifting to 1st gear at no faster than a walking pace, clutch cable adjusted by starting at the lever on the gear box and you'll soon be pleasantly surprised.
Just takes time. Great excuse to go ride.
Monte
-
To a lesser degree, the type of boot or shoe you have can have an effect on shifting .
I do best with a hard boot with the R65, while the oilhead does the best with a 'soft' shoe/boot .
Practice as mentioned is probably the key element in riding an airhead / 'farm implement' .
-
And if this bike is new to you, don't be afraid to pull the gearbox and check out those input shaft splines.
Especially after the contaminated gear oil you found.
There is also another test that needs to be done with the gearbox removed. - Push in/pull out on the input shaft and check for play. It should not be too tight, but not too loose, either.
R/R of a gearbox is a two-day affair for the first time, at worst. I think the hardest part is getting the spade terminals of the neutral switch un-plugged/plugged.
Providing there are no parts that need to be ordered. Have some good 60% Moly grease (http://www.bernardiparts.com/Honda-Moly-60-Paste__08734-0001.aspx) on hand before you start.
And replacement fasteners for the drive-shaft flange connection. And a rubber-tipped attachment (http://www.pbase.com/tomfarr/image/122299542) to lube your swing-arm bearings. And a 27mm socket (http://www.culayer.com/Joes_tools.htm) for the swing-arm lock-nuts. Some sockets will work as they come from the store - others will need to have the outer surface removed to fit in the available space. Any of them should have the taper removed so you get full purchase of the socket/fastener.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.pbase.com%2Ftomfarr%2Fimage%2F136965770.jpg&hash=7fea2e3cb93a0407a969e51382400bb8703d24f4)
The Moly paste goes on the gearbox input shaft splines only - not the mating splines on the clutch plate!
Also put a dab on the tip of the push-rod, after checking it for deformation.
The Moly paste is also used on the large splines on the rear wheel hub of the twin-shock models.
Mono-shock bikes do not have these rear splines.
And don't forget that second gear oil change for your gearbox, to clean out the junk that was in there before. Every potential purchase should have that gear lube checked for color. If it is coffee w/creme, walk away or at least beat the price down $500.
-
HI Bangpaul,
+1 what Rob said. The Snowbum has an excellent file to read on this. READ THIS FILE buried on this website. http://bmwmotorcycletech.info/
Change the oil in the gearbox/drive shaft/final drive often -- at least once a year. I change it out twice a year because I use a 85W140 in the summer and 80W90 in the winter.
Also milky oil is a sign of water in your oil. This is bad. Milky oil in the tranny is a sign that water is gettting into the drive shaft and the drive shaft is overfilled. It only needs anout 100 to 120cc of oil. Any more (the book says 150cc) and once you get to 65 mph or faster the oil slings through a vent hole between the tranny and the drive shaft into the tranny.
For Milky oil in the drive shaft, Change out the rubber drive boot and the rubber bell on the bottom of the speedo cable and seal the top of the rubber speedo bell with RTV and a tye wrap or heat shrink tubing from Radio Shack.
Good luck.
-
... 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
-
... 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....
-
Believe the weather wizards said today, Thursday, was the 36th day in a row over 100°. A toasty 106° today but hotter forecast for tomorrow with continued 100+ days all next week.
My rides are not much more than an hour just after sun up. Low 90s by the time I get back. One of our intrepid local news hounds provided a photo of his digital thermometer laid on a street just three blocks from my house... 145°F. I worry about the bike's tires!
Monte
-
When it get that hot out on the highway, the heat radiates through the souls of my Tourmaster Rain boots and, no sh|t, burns the bottom of my feet. Doesn't seem to matter if I'm going 55 or 70.
I haven't figured out what to do about that one...I just suffer though it. :-[
-
Milky oil in the tranny is a sign that water is gettting into the drive shaft and the drive shaft is overfilled. It only needs anout 100 to 120cc of oil. Any more (the book says 150cc) and once you get to 65 mph or faster the oil slings through a vent hole between the tranny and the drive shaft into the tranny.
This makes sense to me. It was noticeably worse after a weekend of lots of riding, often in the wet, and usually over 100kph. I suppose I better change the drive shaft oil too. Replacing the boot was always inevitable, I was just hoping to put it off for a while.
-
I suppose I better change the drive shaft oil too.
Have you looked in your final drive, yet?
Engine, gearbox, drive-shaft and final drive should have been changed as soon as you got it home.
As well as checking tire pressure - do that often and BTW, the pressure figures on the sticker under the seat or in the handbook are obsolete.
Do you use PSI in Australia? If so, consider 36 PSI as a starting point.
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.
If it is over 10%, increase your cold pressure because the tires are flexing too much.
If it is less than 10%, decrease the cold pressure because they are not flexing enough.
At least, that is how it used to be.
You should also plan on renewing your brake fluid sometime soon, as well as fork oil.
Re: forks - there are tiny little 10mm drain screws on the back of the fork legs. Use new "crush" washers and DON'T over tighten them! They will strip the threads on the aluminum legs easily.
In fact, there are MANY steel-to-alloy mates on these bikes. They prefer a soft touch.
-
In fact, there are MANY steel-to-alloy mates on these bikes. They prefer a soft touch.
...and a torque wrench!!!! 8-)
-
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.
-
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.
-
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?
-
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 (http://www.alibaba.com/product-gs/466155926/Professional_10mm_Screw_Driver_Socket_Nut.html) or a palm-ratchet (http://www.pbase.com/tomfarr/image/133748884.jpg).
-
... 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?
-
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.
-
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.
-
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.
-
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?
-
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.
-
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:
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.suraklyn.com%2Fr65_forum_gallery%2Falbums%2Fuserpics%2F10004%2Frear_swingarm_finished.jpg&hash=64f3044abdf76509c7b72e2686bd8173527104d4)
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.
-
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.
-
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.
-
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.
-
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.