Final Drive Oil Seal Failure

[Bear]

There is some value in keeping your bike squeaky clean---potential problems are easily seen and diagnosed.

Today I noticed some oil spatter on the left (only) side of my rear rim. When I got home and in my garage, I felt around the differential and felt some gear oil that had leaked out of the final drive case.

I looked in my trusty Shop Manual and found what I considered was the culprit--then on line to find the part number. #91265-MBO-003, 60mmx89mmx8mm, $14.95.

Spoke to the service manager at North Country H-D, Honda, and he said to bring the bike in. The bike is still under warranty. He suspects the same thing--given my description of the problem.

While I was in college, I worked for a BMW Dealer who taught me a lot--particularly about shaft drives. Those have not changed over the years. I did not think that what I was taught by this brilliant German mechanic would come in handy all these years later. Thank You Herb Lueck.

My bike has 2100 miles on the clock. Has anyone else had this problem?

 

[Mellow]

Was it definitely FD oil or possibly moly from the splines? I'm assuming the original tires are one?

 

[Chucksklrst]

There is some value in keeping your bike squeaky clean---potential problems are easily seen and diagnosed.

Today I noticed some oil spatter on the left (only) side of my rear rim. When I got home and in my garage, I felt around the differential and felt some gear oil that had leaked out of the final drive case.

I looked in my trusty Shop Manual and found what I considered was the culprit--then on line to find the part number. #91265-MBO-003, 60mmx89mmx8mm, $14.95.

Spoke to the service manager at North Country H-D, Honda, and he said to bring the bike in. The bike is still under warranty. He suspects the same thing--given my description of the problem.

While I was in college, I worked for a BMW Dealer who taught me a lot--particularly about shaft drives. Those have not changed over the years. I did not think that what I was taught by this brilliant German mechanic would come in handy all these years later. Thank You Herb Lueck.

My bike has 2100 miles on the clock. Has anyone else had this problem?

Was the final drive over filled? It will burp out of the vent from time to time if over filled. Does not take much. Also sometimes what looks like oil might just be brake dust and dirt. You will really need to pull the wheel to check the seal leakage. Not saying it is not the seal but with 2k miles on the clock I would be skeptical. Is it leaking between the final drive and the swing arm drive-shaft tube? The mating service by the 4 final drive nuts? If so then it is for sure a seal.

 

[Bear]

Mellow, The rear wheel has never been off. If it was Molly from the spline, it would have appeared long ago. This was definitely gear oil--I was able to scoop up enough from the bottom of the differential case to make that call. It's not an uncommon problem with shaft drives--relatively easy to fix--just a PITA to get apart and back together again. (No Tupperware involved here) There is one oil seal and three "O" rings involved. All three "O" rings and the seal will need to be replaced.

I have done a number of BMW with that issue--my R-50 included. This problem manifests after many miles--in this case it appears to be a premature failure---more accurately, a failure in the making. The bike will do 47 miles to the dealer tomorrow since the leak is quite minimal--about a tablespoon full so far. There is close to a Liter in that case and I do not anticipate a catastrophic failure. I feel pretty comfortable with my diagnosis. If it is something more benign, I'll be happy. The heat waves are over and the good riding is now----so is the sailing. Decisions, decisions.

 

[Bear]

Chuck, That is entirely possible. My question is, Why now? The wheel has not been off. The bike was never dropped, and no fluids were added to that part of the bike. I have done an oil change. If the differential was overfilled at the dealership when the bike was commissioned, why would it only manifest after 2000+ miles? It is definitely not brake dust--wrong side, and brake dust would not show up as spatters on only the left side of the rim.

I did have my close friend, Phil Reid, who runs an independent MC Shop specializing in high performance sport bikes (my Ninja days) look at the bike. His opinion is that it is an oil seal about to fail. He recommended that the dealer should remedy the problem because the bike is still under warranty--and will be for the next four years.

 

[Mellow]

Not trying to be anti-BMW, but none of my Hondas (Valkyrie 50k miles, ST1300 30k miles, GL1800 X2 both w/50k miles and current ST1300 w/55k miles) have ever had an FD seal issue and I can't recall one being mentioned on the ST-Owners site so I argue just how common that issue is... This may have been mentioned on the ST site and I just missed it, that's quite possible, but I just don't see it as a common problem with Honda FD units.

Either way, it should be a warranty issue and it's possible it's you just won the lotto and are the 1 in thousands that this is happening to.

Heck, my ST1300 U-Joint failed at 50,000 miles and it's only one of a handful reported on the STO site but after a couple of them the panic was starting... ironically, mine failed after I posted to not panic after another member's failed.. LOL... I should learn to just shut up sometimes.

 

[Bear]

It's probably an isolated incident---or it could be nothing at all. Certainly I'll have the dealer look at it. When I worked at the BMW Dealer, it was back in the very early 60s. I can't say, in retrospect that it was a common problem, but we did fix a few with that issue. I do hope it is nothing serious---will have the service people check it out--better be safe than sorry. I will keep you posted after tomorrow's talk with the service manager.

 

[Phil Tarman]

I had oil on the left side of my wheel once and thought that a seal must be failing. I wiped it off and it's never come back. That was probably 20,000 miles ago.

 

[Mellow]

I had oil on the left side of my wheel once and thought that a seal must be failing. I wiped it off and it's never come back. That was probably 20,000 miles ago.

That was probably just moly from the splines, some of it will sling around and eventually make it out and on the wheel when too much is used on the splines during a tire change.

 

[Phil Tarman]

Well, I don't really think so. It was a streak of oil. I wiped it off and it never came back. It hadn't "slung" like the moly does, it just ran from the center of the the final drive.

 

[Mellow]

Interesting, maybe a few heat cycles helped to seal it up and eliminate it.

 

[Bear]

I sure hope that you-(Mellow) and Phil are right. I do know that there is no oil on the floor of the garage. It's raining today--so I'll probably see the service manager tomorrow.

 

[charlie b]

Definitely let us know.

Final drive issues are "common" in one sense of the word, ie, they do happen. Kinda like the spline issue on the NT's with a few that did not get properly lubed at the factory. I wonder if that is part of the problem here, manifesting itself as taking out the seals too?

Moto Guzzi's are "known" to have drive problems. That means that most are good for over 100k before even looking at the system while a few will shed a ujoint after 60k. And some of the 300k and 400k bikes have never had a driveline problem.

 

[ARKNT]

Just a note on final drives on the NT.
Anyone ever notice how hot it gets? I was doing some experimenting/adjusting on the rear shock when I thought I may have a final drive problem. The drive case was too hot to keep your hand on. Then I realized it was 103 deg outside, the gearcase is 12 inches above hot asphalt and it is mounted behind the very hot engine. Normal but it tok me by surprize. Now that it is a little cooler the temp seems more normal.

Brad

 

[Bear]

It turns out so far that the oil leak was my fault. In my endeavour to find a solution to scuffed panniers, I put the left side of my bike down on a thin but well padded matress in order to get an idea where contact is made. That caused some gear oil to get near a vent--so in a sense it burped a little. The service manager advised me to keep the wheel clean and keep an eye on it. On the 50 mile return trip there was no oil in evidence. I also felt around the drive, and that was bone dry as well.

The manager said that he would seriously doubt that there was a problem. He has been servicing Gold Wings, ST-1100, Valkyrie, and other Hondas with shaft drives for years and he says that Honda has the best record in the industry. I trust this guy. He is a very competent professional.

 

[Bear]

Oil capacity of the final drive is 130-150cc. That makes approx. a max. of 1/6th of a liter.

Guy,
Thank you for the information. I guess I was too lazy to look it up in my shop manual. At any rate, I am much relieved that it turned out to be a false alarm.

 

[Chucksklrst]

It turns out so far that the oil leak was my fault. In my endeavour to find a solution to scuffed panniers, I put the left side of my bike down on a thin but well padded matress in order to get an idea where contact is made. That caused some gear oil to get near a vent--so in a sense it burped a little. The service manager advised me to keep the wheel clean and keep an eye on it. On the 50 mile return trip there was no oil in evidence. I also felt around the drive, and that was bone dry as well.

The manager said that he would seriously doubt that there was a problem. He has been servicing Gold Wings, ST-1100, Valkyrie, and other Hondas with shaft drives for years and he says that Honda has the best record in the industry. I trust this guy. He is a very competent professional.

That's what I thought, The final-drive burped out the vent. Did not think it would be bad after only 2 k miles. I learned these lessons about Honda final-drives from my 82 V45 Sabre, my 86 1100 Shadows, my ST1100 and ST1300. Also my 94 BMW R100GSPD final-drive. If your bike was a BMW I would have agreed that the final-drive was bad and over due to go bad. Glad it was a false alarm.

 

[Bear]

John,
Thanks for the confirmation. I did take it to Honda after I wiped everything clean. It was a 50 mile ride. When I got to Honda, the service manager and I looked at the drive and found no oil or oil residue. I thoroughly cleaned the drive and no oil came off on the rag. Rode home another 50 miles and still no oil on a white rag I used to go around the drive--just some road grime.

If I do see oil, I will take your advice and remove the rear wheel. I have a Cycle Lift, so I can drop the wheel straight down. I saw the video on removing the rear fender. That has to be one of the worst designs yet.

My 1956 NSU had the best design. You put the bike on the centre stand, pull out the axle,drop the spacer, raise the rear fender which is on a hinge, and you have your wheel. German Engineering--very logical.

 

[Mellow]

Cool, glad to hear it...

Funny thing... whenever I have a problem with my bikes what question do you think I ask myself first:

1 - Wonder what broke?
2 - What did I work on last?

You get one chance to answer and #1 doesn't count.. LOL

 

[Phil Tarman]

whenever I have a problem with my bikes what question do you think I ask myself first: 1 - Wonder what broke? 2 - What did I work on last?

That's funny! And way too true!