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Rear wheel oil

Back to topic. On the Norwegian forum, a guy suggest the cause is rust inside.
The bike was not in use for 5 years, 05-10. So now, with frequent use, and service, that rust is coming off. Hopefully he is right.
Hans
 
My '78 sat for 14 years in a shed; when the the transmission, drive, and differential (rear wheel) oils were drained there was water in all the oils. The water was from accumulated condensation. Not being one to fret over such acts of nature, I plan to ride the bike a few hundred miles before changing all the oils then change the oils again every 1K miles a few more times. Rust in the form of particles would concern me, discolored oil - not so much.
 
I have driven 2500 km, about 4 K miles. The rear wheel oil is changed. I??m not sure if everything is normal.
Hans
 

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I haven't changed the rear drive fluid in my R75/6 since I've owned it, and it's time. Can someone confirm whether it's 80/90 GL5 or one of the other weights mentioned for for the final drive, and how to gauge when it's full/at proper level? Since my 1150 is my daily driver, I have no excuse but to branch out a bit with the R75 and start doing basic maintenance myself.
 
I haven't changed the rear drive fluid in my R75/6 since I've owned it, and it's time. Can someone confirm whether it's 80/90 GL5 or one of the other weights mentioned for for the final drive, and how to gauge when it's full/at proper level?

80w90 GL5 is the right oil. Fill to the bottom of the threads at the filler cap. Maybe spin the rear wheel around a few times and see where the oil level settles too.
 
Ok, now I'm confused...

Sorry guys/gals but I was doing some research and came to the conclusion that after some years of running gear oil rated GL5 I was wrong:type . Some say that the chemicals associated with GL5 rated gear oils are corrosive to "yellow metals" brass etc. and that GL4 rated gear oil should only be used. The yellow metals are in our airheads the tranny and drive train.. So what gives? GL4or GL5
And some say that the chemical additives are not really needed because our airheads are not equipped with nor operate at such pressures and temps, they are talking about the adhesion of a film to the gears for lubrication..simple terms fellas so I guess I can either open up my tranny and take a look or just switch back to GL4 rated gear oil.
Any one else got any info on this?:blush
By the way, I found a new job and now drive everyday to work on my R60/6 aaaaaa life is good down here in the south....75 degrees today in Houston.
Thank you for the prayers and kind words during those difficult times, but we ended up in a better position thank you all.
 
I don't know about /2 and earlier bikes, but 90 wt GL5 gear oil is what I have always found specified for 1969 and later /5 BMWs. 80w90 dino and 75 or 80w90 synthetic is OK too but not necessary.

GL4 is not suitable in either the transmission or final drive as far as I can find specifications.
 
Some say that the chemicals associated with GL5 rated gear oils are corrosive to "yellow metals" brass etc. and that GL4 rated gear oil should only be used. The yellow metals are in our airheads the tranny and drive train.. So what gives? GL4or GL5.

One of the places I have seen this is on Craig Vechorik's site:

http://www.benchmarkworks.com/

Here is what it says under "Tech Advice" and then "Technical Articles and How To" and finally, "Warning About Gear Oil"

"Sadly, Pennzoil no longer makes GEARPLUS?« SAE 80W-90 GL-4

Never the less, the following still holds true:

WARNING:
All modern gear oil available today in local retail outlets is GL-5 grade. GL-5 grade gear oil contains sulphur compounds that attack brass and bronze. BMW transmissions and final drives made before 1992 contain bushings and thrust washers made of these metals. Any brand of gear oil that is GL-5 rated will attack bushings and thrust washers. Bench Mark Works LLC, I use only GL-4 gear oil and we have it available for sale to our customers at the online parts store.

Look for:
acc070A--$8.95--80W 90 GL-4 gear CRC brand

CRC?« Sta-Lube?« Multi-Purpose HYPOID SAE 85W90 Gear Oil API/GL-4:

CRC?« Sta-Lube?« Multi-Purpose HYPOID SAE 85W90 Gear Oil API/GL-4 is specially formulated to meet the unique requirements of API GL-4 service in manual transmissions and transaxles of passenger cars, light trucks and SUVÔÇÖs. CRC?« Sta-Lube?« Multi-Purpose HYPOID SAE 85W90 Gear Oil API/GL-4 is blended from select base stocks and additives that yield a lubricant of exacting quality. This product is compounded utilizing specialized extreme pressure chemistry that provides protection of gears and bearings without being corrosive to bronze components. It contains foam suppressants to prevent wear, which can be caused by lubricant foaming and aeration. Effective rust and corrosion inhibitors protect metal surfaces from the effects of water contamination from condensation and the operating environment. CRC?« Sta-Lube?« Multi-Purpose HYPOID SAE 85W90 Gear Oil API/GL-4 resists the formation of varnish deposits on synchronizer components, thus assuring long, trouble-free operation.

CRC?« Sta-Lube?« Multi-Purpose HYPOID SAE 85W90 Gear Oil API/GL-4 gives the full protection of an SAE 90 under hard driving conditions while providing the flow characteristics of SAE 80W that are necessary during cold weather start-ups. This offers maximum lubrication and gear protection over a wide temperature range.

CRC?« Sta-Lube?« Multi-Purpose HYPOID SAE 85W90 Gear Oil API/GL-4 is designed for manual transmissions and transaxles of both American and import vehicles. It is formulated to be compatible with ÔÇ£yellow metalsÔÇØ, such as bronze, found in synchronizers and other transmission componenets.

BENEFITS:

ÔÇó Meets the performance requirements of API GL-4 Service
ÔÇó Will not cause glazing of synchronizer components
ÔÇó Excellent thermal stability
ÔÇó Outstanding extreme pressure and antiwear protection
ÔÇó Prevents rust and corrosion
ÔÇó Inhibits foaming and aeration


Bench Mark Works LLC
Craig Vechorik email vech@benchmarkworks.com
3400 Earles Fork Road
Sturgis, MS 39769 USA
Telephone/FAX: (662) 465-6444
Toll-free order line: 1-800-323-7102
Hours of Operation
Technical advice: (662) 465-6444
All rights reserved."
 
Ok thank you sir, this is where I got my initial information at Benchmarkworks, in the tech articles. Then did some bing and google searches and got even more cross-eyed:type.... So where do we go from here? Below is the website were I got the initial info.
http://www.benchmarkworks.com/
Thank you Barron that's the place.
 
Ok thank you sir, this is where I got my initial information at Benchmarkworks, in the tech articles. Then did some bing and google searches and got even more cross-eyed:type.... So where do we go from here? Below is the website were I got the initial info.
http://www.benchmarkworks.com/
Thank you Barron that's the place.

Vech knows more about vintage BMWs than almost anybody. And I would certainly defer to him on any pre-1969 model. But I know for a fact that BMW specified GL5 oil for pre-1992 models. I have heard of many many transmission issues in Airheads over the years, but have not heard of erosion of brass or bronze bushings as one of them.

I doubt BMW would have specified GL5 oil unless they thought it was necessary. Other folks I consider Airhead gurus including Oak Okleshen and Tom Cutter use and have recommended GL5 gear oil. Tom specifically uses and recommends Castrol Hypoy C 80w90 GL5 gear oil (which has recently been renamed and I forget the new name).
 
Checked my old /7 shop manual and the owners manual from my '78 R100S and BMW was vague, specifying only "brand name hypoid gear oil."

My '81 VW Vanagon (my going to the dump vehicle) specifically requires GL4 FWIW. There's a Redline product that works for it.

As noted by Paul, nobody's having trouble with GL5 in Airheads.

Yes, the new Castrol name is troubling to me as the name includes "limited slip." IMHO this is simply more evidence that Castrol USA is not a trustworthy company, while Castrol everywhere else is. BMW for sure sells none of their products.
 
The yellow metal in the driveline is a concern for only the pre /5 models, and even then I really don't think it's an issue IMO. I don't see /2 bikes littering the side of the road, anyway! Oak has also expressed the same general opinion in his Airmail tech articles.

As Paul and Kent have said, GL5 is the choice for /5 on bikes.
 
Thats why I posted here, thank you guys for the info now I can keep things as they were...bikes running great 30-40 miles a day for five days a week, I'm loving life:heart
 
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