'75 R60/6 Noobie: mech/maint/lube questions???

I'm a new rider with my first bike, '75 R60/6, with only 14k miles, which the PO says is accurate!

I'm torn between adjustments and minor repairs and upgrades I want to do right now, and just riding the darn thing and worrying about those details next winter. But there are couple of things that look like they want addressing now. I'm not afraid to get my hands greasy (my old Triumph TR-250 made sure of that!), but I'm no expert, and I am new to motorbikes.

First of all, my final drive is leaking. When doing some basic lube/maint/tune-up, I removed the final drive filler plug, and oil flowed out. I plugged it again, and wasn't sure what to do next, but I decided that overfull wasn't good, so I let it drain, sopped a little more out to get the level correct, then closed it up. Fine, but where did the extra oil come from? More research suggested that it was likely that the drive shaft oil was leaking down into the final drive, causing it to overfill. I tried to check the drive shaft oil level, and this is where I started to run into trouble. Different resources give different guidelines.


My big Clymer manual (800 pages, R50/5 through R100GS PD – 1970-1996) says, “Insert a screwdriver or metal rod straight down into the center of the drive shaft fill cap hole until it touches the top surface of the drive shaft... the oil level should be 2mm above the end of the rod.” This makes sense, and suggests that the drive shaft should be completely immersed in oil at the fill hole.


My “photocopy” of the owners manual (which I found through this forum) says kind of the same thing regarding the oil level, except the wording confuses me: “...insert a suitable rod vertically into the filler opening and allow it to rest on the clutch housing...” Clutch housing? Is this a misprint?


A friend's smaller Clymer manual says to use some sort of flexible material as a dipstick, and lower it around the shaft to the bottom of the housing, and read the level from there. An accompanying drawing showed a section view with the oil level at about the middle of the drive shaft diameter, rather than having the drive shaft completely immersed in oil at the fill hole. Using his book, we decided that there was enough oil in the housing.


I used a small wire to clean out the breather holes in the final drive (in hopes of preventing the oiling of the rear brake), and then cleaned the whole casing with mineral spirits and dried it all off so that it was completely clean of any oil and dirt (of which there was some when I got the bike). Now, two weeks later, there is oil coming from the breather hole below the axle, and also from around the filler plug:










So:

• What's going on here?
• What should I do about it?
• What's the correct oil level for the drive shaft housing?

Thanks!!!

On some older Airheads there will be slight leakage from the driveshaft housing to the final drive. Sometimes from a wonky seal, sometimes from threaded "seal carrier" in the final drive. The driveshaft oil transfers to the FD, the FD oil lever rises and the seals leak. Mine has done that since 1974 and on odd-numbered months I get a 100cc syringe, remove the FD fill plug and suck out the excess oil (typically 30-60cc, an ounce or two) and re-transfer it back to the driveshaft housing. Once a year I'll drain the FD, driveshaft and gearbox oil and put fresh dope in. Forget the wire dipstick tip-- put 150cc oil gear oil in and forget about measuring oil that level.

The oil leaks from those two vents because it's supposed to instead leaking onto the brake linings.

Repair is by replacing the seal and using a proper sealant on the threads. Repair is by sending it out to someone experienced in that final drive because the preloads and gear contacts are very tricky and can't be donbe by reading a Clymers or doing it once a decade. Hanson's does good work, as does Anton Largiader and Ted Porter (Beemershop).

Thanks, Bill!

We actually thought about trying to catch the draining oil and put it back into the drive shaft housing, but we couldn't figure a sensible way to do it without re-introducing contaminated oil. We didn't have the right oil at the time, so we left it alone. I like your catch-and-release idea, but I wonder, based on the amount of leaked oil present only two weeks after our level adjustment, if my leak isn't worse than yours? I'll get the right oil, drain both units and start fresh with the proper quantities. Then I can carefully monitor the levels and determine how serious the leak is.

As near as I can tell, the oil is coming from two places: the weep hole below the axle (it's doing its job), and the final drive fill plug - is the latter a vent? It does have a washer; should oil be coming from that plug?

I'll make a note of your recommendations for (hopefully far in) the future...

That was a great write up by Bill. It's really true what they say about the cheapest thing on an Airhead.

Use GL-5 80-90 wt gear oil.

Be on the look out for cream colored oil in the rear drive and swing arm and transmission. I found this last year in all three. It comes from water getting inside and it mixes with the oil. First it makes the oil a little like coffee w/ cream then more water turns it whiter and whiter. Most of the time the problem is the boot on the speedo cable. Always keep this boot in good shape and put a little silicone in it to help keep water out.

I haven't figure out why I got water in all three but I'm keeping an eye on it and will probably have to rebuild or reseal all three.

Thanks, Disston! I'll be on the lookout for the 90 wt mocha.

Any ideas about whether this would leak more while under way, or when standing still? Or doesn't it matter? There isn't a drop of oil on my garage floor, but there's clearly a leak...

The previous owner always added lead substitute with every fill-up. Another guy around here always adds that, plus fuel treatment against the evil ethanol additive, which I cannot avoid here. What's the conventional wisdom on fuel octane/additives? What are we protecting against... pinging? valve wear? ethanol damaging rubber bits? (ethanol is murdering all our local lawnmowers, outboards, chainsaws, etc...)

I think if you computed the value of the protection against the cost of all the additives the cost would be more than the amount of protection. But maybe not. I have a bottle of each of those. I used the lead additive a couple of times. I used the alcohol eliminator once. So I still have two full bottles.

I've read pro views of both of those things but I think I'm just a no additives kinda guy. I change the fuel lines once a year usually and check for bad O-rings. I don't usually need any. When I used the lead substitute it was gumming up my plugs. I think I'll be able to afford the lead free valve seats someday soon so I've decided that will be a more permanent solution.

My valve adjustments were not stable for a while, about six months ago, now they seem to have leveled off and I'm not using substitute anymore. Keep an eye on the valve lash. If the valves are closing up, especially the exhaust, it's time to start worrying.

BTW, my bike is also a 1975, but larger. Our vintage Airheads are supposed to handle the no lead better than some others. I can't give you the complete rundown but the valve seats along about '75 weren't the best but they aren't the worst either. And where as my 900 cc's is tough on valve wear your little 600 is much milder. Many of the 600s never have a problem with seat wear. You still may need head work someday tho.

If you use that lead substitute keep an eye on your plugs for fouling. If this happens those deposits are gumming up your innards.

I didn't read through all the posts but that oil leak is the small seal on the deep end (outside) of the FD, not the input shaft seal. Whole different animal. You need a blind puller for that job. I find the input seal rarely leaking. I think the oil can migrate into the FD with a perfect seal to some small extent. If a little oil migrates back. I call that normal.

Hi Supershaft-

Please forgive my ignorance, but I'm really new to all this, and I have no idea what it is you're describing. I'd like to understand your input...

What do you mean by "deep end (outside) of the FD"?

If by "that oil leak" you mean what I've shown in my photo, I'm guessing that perhaps what I have shown should more accurately be called an oil overflow. The leak is between the drive shaft housing and the FD, the excess oil in the FD overflows through the weep holes, just like it should. No?

What job?

Are you suggesting that an exchange of oil between the drive shaft housing and the FD in both directions is normal?

Well, put the bike on the center stand, and opened the final drive fill, and the oil started to surge toward the top again. I raised the rear wheel till the front wheel touched the floor, and the oil leveled out just before spilling. So I removed about 30 cc's with a big syringe, and when I lowered the rear wheel again, the level ended up just about at the bottom of the filler hole's threads. I transferred the oil back into the drive shaft fill, and it ate it right up.

I rode for about 20 minutes, then I re-checked the FD level: same as where I left it, no drips. To be continued...

But, while I was riding, I started to lose power - in traffic. :eek1 I found a place to pull over just as the engine died. Switched fuel to reserve, and all was well again. Which leads me to the next discussion - fuel and fuel economy.

One of the reasons I bought the bike was for fuel economy on my commute to work. Last week I filled the tank, for the first time, right up to the bottom of the filler spout. I did the same again today, and it took 3.5 gallons. On that 3.5 gallons I rode 146.6 miles - 41.5 mpg. Is that normal? Because that's what I get on my commute in my Honda Civic. If it is normal, I'm disappointed. If it's not, any suggestions?

The manual specs say the tank is 4.8 US gallons. Does that mean that the reserve is about 1.3 gallons? Does all this sound right?

You usually can't get the last bit of gas out so reserve for you should be 1.1 or 1.2 Depends on how short or long the straws of the petcocks are.

The "weep hole below the axle" is for the smaller axle seal on the inner side of the Final Drive. There is another one you missed-- this is just inboard of and ahead of the FD drain plug. That drain is from the big ("main") seal on the brake side of the axle, where the rear wheel drive splines are. Oil is weeping out of those two drains and the wind is whipping it back towards the fill plug. Clean that area off and monitor. Not a big concern.

The gas mileage should be 48-50mpg. The bike is in an unknown state of tune, etc, and you can improve on 41mpg, but not a whole lot. Yes, many cars nowadays can get as good a gas mileage. The big difference is the smiles per mile...

Bill-

I didn't miss the hole near the drain plug. I didn't mention it because I don't believe that there's any oil coming out there. Could be, but it looked dry inside the hole, where you can see even in my photo above that the upper hole has oil in it. There was enough oil all around the fill plug to make me suspect a leak there, rather than just windblown residue.

As I understand it, the washers for all these plugs are one-use-only crush washers - well, my fill plug washers have been crushed more than once, and I sure don't have any extras. This is why I didn't just drain the oil and start fresh - I didn't want to take the chance on creating more leaks. I'll be visiting civilization next week, and I'll stock up - they're not very expensive!

I wonder is it likely that the oil could be seeping out from around that FD fill plug with the "used" washer?

I think oil can seep from around a used washer. Especially one that's been used many times. Should also be at least cleaned if you have to reuse them sometimes. I've been guilty of this one multi times.

I'll be visiting civilization on Thursday (MAX BMW in NH) - Can anyone suggest a basic shopping list of staples I should have in my "pantry"? Oil and air filters, some handfuls (handsful?) of whatever crush washers I need. They're cheap - where are they used, other than the final drive components in question? Maybe the "correct" shock oil?

What else should I be considering? What "has to be" BMW brand, vs. what can I safely go generic on?

~ Matt

Matt- at MAX speak w/ Rusty in the parts dept.

+++++++1 Rusty is a GREAT GUY!!!!!!!

Got my parts at MAX - pretty flashy joint. Lots of salesmen surrounded by fancy bikes waiting to pounce on prospective customers... of which I wasn't. Took over an hour to buy some filters, gaskets, crush washers and a few quarts of oil. Wasn't sure what else to get, or whether I needed to get BMW oil, but I was there...

Can anyone describe "pinging" to me? Yesterday, my bike started making a rapid, somewhat random, not-too-loud "tinking" noise when under load, i.e. climbing a long steep hill at about 3500 rpm. Lower gears and higher rpms helped, but I have to keep the bike moving, for goodness sake! I might have called it a "ticking", but it has a vaguely metallic tone and it isn't like the ticking of what I think is the valve lifters - and it only happens when I load the engine. I have high-test gas in the tank, but no other additives.

Is this the dreaded pinging that these bikes are "known for"? Will it cause damage? What should I do about it?

Use premium grade gas and check the timing. Otherwise, install low-test base gaskets to lower the compression ratio.

Thanks, Bill. I take it from your repIy that this is pinging that I'm experiencing. What kind of damage will it cause, and how quickly? If it doesn't happen often, is it safe to ignore it?

I use premium grade gas, and checked the timing a few weeks ago. Should the timing be set a certain way to avoid the problem?

Yep, the sound is a lot like gravel rattling around in a tin can. No immediate harm but it ain't good-- back off the throttle a bit and/or keep the RPMs up. Double-check the timing-- it shouldn't be past the "Z" (or "F") mark.

The R60-series has a cam profile that gives a high effective compression ratio and(at least the /5) has 9.6:1 physical compression ratio and was designed to run on the bestest tetraethyl lead Premium gasoline. I'm thinking the /6 was the same way.

In the early '80's when good leaded Premium became scarce I had this same serious problem and my solution, at the time, was to install a set of "Low Test Base Gaskets", a BMW part that lowers the CR from 9.6 to 8.6 (-ish) and allows the engine to run happily on Regular. You take a slight hit in performance and gas mileage, but not a devastating one. Last year I did a top end on my R60/5 and did (my one last) performance mod on it: went back to the normal, high-compression base gaskets and modded the heads for dual plugs. Bike is a little zippier and I guess one could consider the lower plugs a Farkle.

Your call...