All sortsa' oils

[Barry]

Good job you checked !

Rear bevel drive has had water in it for sure which is not so common as else where as the only way for water to get in is through the vent on top. Maybe it was jet washed.

It could have been worse in that water in the gearbox is even less desirable and more expensive. The speedo drive boot is the culprit for water in the gearbox and the swinging arm rubber boot will let it in to the drive shaft oil.

Oil migration between the transmission parts is not that uncommon so I wouldn't panic too much yet.  I'd start by just refilling with the correct quantities of clean oil and flush out again after a few miles. Levels are as you say. 800cc should get you to the lower edge of the fill hole on the gearbox.  Final drive takes 250cc to the bottom of the filler threads. The Drive shaft is supposed to take 150cc but it's generally accepted that this is too much and if you put that in it will usually just migrate else where. Drain well and put in a measured 100cc or 120cc at the very most and it will usually be fine. Of the 3, the gear box oil level is most critical. The final drive and drive shaft will probably come to no harm with less oil then specified.

Maybe oil will still migrate and you'll need new seals and maybe it won't. When I first got my bike the drive shaft oil had finished up in the final drive but after my first round of oil changes to the correct levels it has stayed put.

80W90 GL5 is what you need. Semi synthetic has some benefits but perhaps not for the first flush and not while the seals might be in question.

BTW how much fuzz was on the magnetic drain plugs ?

[steve hawkins]

Lukas8165,

Chap, you are only 30 odd miles away.  How about meeting up for a 'Southern Softy Shandy' and I'll do my best to get yourself educated proper like.

I am at the end of the A419 in the much maligned Swindon Town.

Cheers

Steve Hawkins

[montmil]

Begin by draining all fluid reservoirs. To save that expensive lubricant, some folks will flush a bit of kerosene and drain thoroughly. The milky oil indicates water being emulsified with the oil. Thats not good for bearings or steel shafts, etc.

I do not trust the fill level plugs for their so-called accuracy. I much prefer to add the manuals indicated amounts; except I do run the gearboxes on all three of my Airheads with a gear oil indication at halfway twix max and add. helps reduce blowby, drips and a messy bike.

Da Snowbum states that the driveshaft can safely run will much less gear oil than the manual specs.

An overfilled gearbox could be the culprit as could be a failed shaft seal allowing the oil to pass into the boot.

Water in the final drive could enter via the "acorn nut" breather on top of the case if a PO had ridden in deep water or did frequent hi-pressure washings. Don't do that. If gear oil is passing beyond a seal, then water lwaked into the boot might also migrate to the final drive.

Your work is laid out for you, Lukas. Drain everything. Flush if you choose or use an eco lightweight oil as a flushing agent. Refill all with the manual's specified amounts of oil types and weights.

Replace that rubber speedo cable boot, too.

Sing out should you have additional questions. Good luck.

[lukasgrech]

Thanks for the extensive help and all the info everyone, very much appreciated!

An oily weekend it shall be!

I haven't undone the drain plugs, but I'll keep an eye on how much metal fuzz is stuck.

[lukasgrech]

Lukas8165,

Chap, you are only 30 odd miles away.  How about meeting up for a 'Southern Softy Shandy' and I'll do my best to get yourself educated proper like.

I am at the end of the A419 in the much maligned Swindon Town.

Cheers

Steve Hawkins

Steve,

Would love to meet up - my oil situation and British weather permitting, hopefully we can do so soon.

[lukasgrech]

Monte, when you say a failed seal, is that likely to be the output shaft oil seal?

How much of an adventure is it to replace that?

[Tony Smith]

 [/quote]


I've being running engine oil with with a 30 % synthetic content (and that's a lot more than some so called semi-synthetic oils) without noticing any problems with seals leaking. [/quote]


Not a specific reply to you Barry, more a general comment.

There is nothing wrong with the seals, they are in main, catalog single and double lipped seals that are well spec'd for the task and provide years of trouble free service.

There is none of the nonsens of earlier generaion engines and gearboxes involving oil soaked felt or graphite impregnated sisal to try and replace periodically.

Yet there is a mythology that BMW /5/6/7 engines and gearboxes are prone to leaks.

Bollocks I say.

What you do see is that the basic engineering of the BMW engine and gearbox is so fundamentally sound that engine cases and gearboxes are out there from the late 70's with seals that have never been replaced and which are only now getting a bit "leaky".

Don't know of too many car engines that are still oil tight after 35 to 40 years.

[montmil]

Monte, when you say a failed seal, is that likely to be the output shaft oil seal?

How much of an adventure is it to replace that?

Prior to getting all ramped up about possible extensive repairs, drain all fluids and refill as discussed.  I hope you have a shop manual in your tool box. There's also a downloadable pdf Owners Manual for the 81-84 R65s in the R65 Technical FAQS/procedures section. Check page two and scroll down to find it. The lubricant quantities should be the same for your model. Without a benchmark to go by, you'll be shootin' in the dark. Clean up the bike and watch for the Three Dwarfs... Weepy, Seepy and Leaky.

I can almost guarantee you that the improperly installed boot is your primary issue. Remember, air currents pushing oil drips to strange places have caused more money than necessary to be thrown at motorcycles.

Also, acquaint yourself with The Snowbum. Rather long-winded and very wordy but an Airhead treasure of technical knowledge. Check him out for details regarding your concerns.
http://bmwmotorcycletech.info/technical-articles-list.htm

[Barry]

Lukas,

You ideally need the 79 riders manual as it has the correct fill volume of 250cc for the final drive. 81 on models take 350cc and the fill/level plug arrangement is different. Also engine sump volume is different. We 79'ers are very much in the minority so it's helpful to know the host of subtle differences between the models. I've attached a chart which covers most of them.

PM me and I'll e-mail you a copy of the 79 riders manual by return.

You'll need a proper workshop manual for the seals but I agree with Tony. Mine will only get done when they need it. Still have all the original 35 year old seals and no drips anywhere. A little misting around the nether regions and a trace of oil on the shelf under the gearbox but who hasn't. Consumption between changes is near zero.    
Don't know the history of your bike but if it has been laid up for a time don't judge the seals until it's had some use.

[Lucky_Lou]

There is a pdf in the Tech/FAQ s the riders manual for 81 ? I posted it but mine is a 79? i use Castrol Classic oil they have it on offer at Maccess if you have one near you.
Lou

[Barry]

Lou,

You have the 79 manual in PDF somewhere as you sent me a copy. Size is the reason it's not posted here. At 5MB it's too big but OK as an e-mail attachment.

[Lucky_Lou]

Lou,

You have the 79 manual in PDF somewhere as you sent me a copy. Size is the reason it's not posted here. At 5MB it's too big but OK as an e-mail attachment.

I think I saved it on my Seagate Hard drive as this is a new lap top and I saved all my old files.... if anyone is desperate for it I will dig it out but I think the oil specs would be the same for all the R65,s anyway.
Lou

[Barry]

Lou,

I've already sent it to Lukas so he's OK.  

Oil specs will be the same but it will provide the correct fill volumes for final drive and sump which are different to the later models.

[lukasgrech]

Right.

All fluids changed.

To re-fit the boot properly I had to take out the battery and battery box, this gave me better visibility of the boot, which is in absolutely horrible shape. It's doing precious little in terms of keeping oil in, although it still does enough of a good job keeping dirt and gravel out of the driveshaft.

The driveshaft oil drain plug must have been over-tightened at some point, as it does not unscrew, turning it clockwise or anti-clockwise both end up in it tightening up and stopping.

I added 100cc of driveshaft oil, and then checked the level with a dip stick as per the manual instructions, and found it to be at about 2mm height from the top of the driveshaft, which leads me to believe that it was running on very little oil beforehand.

At some point I'll have to replace the rubber boot, and since that will involve quite a dismantling, I'll deal with the driveshaft oil drain then.

[montmil]

... The driveshaft oil drain plug must have been over-tightened at some point, as it does not unscrew, turning it clockwise or anti-clockwise both end up in it tightening up and stopping.

Odd. Is it leaking or is it oil tight?