Tranny Oil for R25/2

[20774]

I'm looking to do my first fluid change on my "new" '52 R25/2. The owner's manual says to use engine oil. I called Vech and ordered fluids (before I had the manual in hand) and they sent me GL4 80w90 gear oil. I understand the GL4 part...bronze parts, etc. But should I be using engine oil instead? I have no clue if the seals have been changed to accomodate the gear oil. I'm at least 4th owner, and probably 5-6th owner. The bike was in police service through the late '50s and '60s but I have no idea what maintenance or changes were made.

[rspennachio]

21055

[PGlaves]

I'm looking to do my first fluid change on my "new" '52 R25/2. The owner's manual says to use engine oil. I called Vech and ordered fluids (before I had the manual in hand) and they sent me GL4 80w90 gear oil. I understand the GL4 part...bronze parts, etc. But should I be using engine oil instead? I have no clue if the seals have been changed to accomodate the gear oil. I'm at least 4th owner, and probably 5-6th owner. The bike was in police service through the late '50s and '60s but I have no idea what maintenance or changes were made.

If Vech sent it to you I would have a high level of confidence you got the stuff you should be using.

[20774]

If Vech sent it to you I would have a high level of confidence you got the stuff you should be using.

Paul -

I feel the same way, but actually it was Richard who I ordered from at Vech's shop. Vech is too busy to answer the phone! Richard's good, don't get me wrong. I called him back and asked specifically about it. His take was to drop the oil that's in there and smell it...if it has some sulphur smell, it's gear oil and then use gear oil.

But I don't think that's a valid way to go. It's not correct to just use what the last person used. This bike is by way of Autobahn Craftwerks in Cincinnati and before that Blue Moon in Georgia...before that Germany. I have messages into both places to ask what they did regarding the tranny.

To me, it's all about the seals that are in the bike. From the Yahoo Mono board, it was stated (ie, in a service bulletin) that the seals changed in the late '60s. So, if my '52 still has the original seals, seems like I should still use engine oil.

One thing I noticed when bumping the kick start lever while looking for the timing mark. I saw, felt, and smelt a dab of engine oil on the edge of the flywheel at one part of the circumference. Could be rear main seal. Could be tranny input seal if someone used engine oil and the seals had been changed to work with gear oil. :dunno.

[James.A]

I put straight 30w motor oil in the transmission of my R27 as per the owners manual. The result was/is that all the wierdness I had been experienceing with the transmission went away with the gear lube that I drained out. I ended up having to underfill the transmission by 30cc's to prevent leaking at the input spline. This I learned after having to replace a clutch disc because of oil contamination. I had initially overfilled with gear lube. After discovering that the clutch disc was ruined, I experimented with 30w and volumes to determine what volume of oil would not leak past the input seal. I then changed the clutch disc and re-filled to the already determined level. All this on a transmission that had been jobbed out for a re-build. As of last fall, the little bike was working just fine.

[35634]

21055

how do you get oil out this tranny?

DON'T CHANGE THE TRANNY OIL! It is HERmetically sealed and draining it may traumatize the output shaft!!! :buds:nyah:D:nono:):nyah:sick

[85K100LT]

I put straight 30w motor oil in the transmission of my R27 as per the owners manual. The result was/is that all the wierdness I had been experienceing with the transmission went away with the gear lube that I drained out. I ended up having to underfill the transmission by 30cc's to prevent leaking at the input spline. This I learned after having to replace a clutch disc because of oil contamination. I had initially overfilled with gear lube. After discovering that the clutch disc was ruined, I experimented with 30w and volumes to determine what volume of oil would not leak past the input seal. I then changed the clutch disc and re-filled to the already determined level. All this on a transmission that had been jobbed out for a re-build. As of last fall, the little bike was working just fine.

I think this is the correct answer!!!:dance


"I put straight 30w motor oil in the transmission of my R27 as per the owners manual."


Age teaches us when in doubt pull out the manual :brad


Boy I hate when the wife is right:violin

[gertiektn]

I changed the gearbox oil in my R50 and put in Casteroil 30W. I also changed the other boxes to this oil per the manual. No leaks and no problems. My speedo says +18K miles. Tranny works good and shifts well.

I drained out some thick stinky stuff of at least 80W the tranny was stiff feeling.
I have no idea of how old the oil was. The bike had been sitting for about 20 years.