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Discussion Starter #1 (Edited)
Final Drive - Small Oil Leak

Let's talk final drives. I was washing my '09 K1200LT (29k miles on it) today and noticed a shmear of dirty sludge/oil on the bottom of the unit, centered around where the black rubber "boot" is fastened with the metal band. I ran my hand across it; there are no drops waiting to drip off or anything, but there's an area of black goo that is thickest at the bottom-most point of the metal band.

What's next? Understanding I won't get into something like that, should a dealer take a look at it? And of course, the warranty expired about 2 weeks ago. Shoulda bought an extended warranty...

Is it OK to ride or should I cease riding it immediately? I was planning on going to Cleveland and back tomorrow (< 300 miles round trip), and to the Iron Horse Lodge next weekend (1100 miles round trip plus day trips).

This photo shows the view from the rear. It desn't look too bad now because this is after it was washed, but there was a very light film of oil on the drive housing. I thought this was road goo until I got closer into it. You can also see a light film on the rubber boot.



Here you can see where the sludge/goo/oil/whatever is thickest. You can also see that oil has dropped down onto the arm below the final drive - look closely, on the inside of the curve.



I'll be waiting, hoping for some good news from you all, but we'll see what you have to say. I already sent a PM to Dr. Zeiler, but I know there are others out there (CharlieVT and Saddleman come to mind) with similar experience and knowledge that will have helpful comments.

Thanks.
 

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Loosen the band that secures the rubber boot to the FD and pull the boot away from the FD just enough to see how much lube runs out.

You have either a leak at the transmission output seal or the final drive input seal. These are known problems.

You can check the final drive lube level easily by removing the fill plug and looking in. The lube should be close to the bottom of the threads of the fill hole.

This is not an emergency and you can continue to ride. Generally the leaks are reported to be slow. It would be a good idea to make sure the lube level in both the tranny and final drive isn't too low, but it is unlikely to be very low. You can get an idea of how much fluid has leaked out by seeing how much you get when you loosen the rubber boot.

Ultimately, if you are not a DIYer, you'll need someone to determine if it is the FD or tranny that is leaking and replace the seal.

HTH
 

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Discussion Starter #3
That's excellent news. Thanks.

I'm familiar with the final drive gear oil change, as I do that myself. (it couldn't be easier...)
How do I check the transmission oil level? I have always let the dealer do that.
 

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2011 R1200RT
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One of the reasons I don't wash my bike is that I don't want to find out things like Howard experienced. Out of sight = out of mind! Isn't ignorance bliss? :D
I had a bad seal on my final drive that replaced under my extended service contract (cost me $25 copay :) ) and even now my FD is always "sweating" fluid, but not enough for me to worry about it. ;)
My original leak was pretty bad and there was a puddle under the bike when Dan Martin discovered it and left a note on my bike. The Sturgis dealer did not have the part so John Z lent me a FD to go back home.
Howard's drive is nothing like mine so it should be safe to ride until a convenient time comes along to investigate and repair.
 

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hschisler said:
That's excellent news. Thanks.

I'm familiar with the final drive gear oil change, as I do that myself. (it couldn't be easier...)
How do I check the transmission oil level? I have always let the dealer do that.
Howard, you have to remove the front right side footpeg plate to access the fill plug on the tranny. Just remove the fill plug and feel if the level is close to the bottom of the thread, just as you would check on the final drive.
 

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hschisler said:
That's excellent news. Thanks.

I'm familiar with the final drive gear oil change, as I do that myself. (it couldn't be easier...)
How do I check the transmission oil level? I have always let the dealer do that.
Howard,
The transmission fill plug is located behind the right drivers footpeg. You fill it the same way as the rear drive. The drain is up under the center stand.
 

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Wrencher Extraordinaire
2005 K1200LT
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Like my PM and Curtis said open her up and see how much oil is IN the bottom of the swingarm.
 

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Have some string or a bungee handy to hold the foot peg out of the way after you remove the 3 screws. Checking and changing this fluid is as easy as the final drive. I used to do all three in about an hour without rushing.
 

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Discussion Starter #9
CharlieVT said:
Loosen the band that secures the rubber boot to the FD and pull the boot away from the FD just enough to see how much lube runs out.

You have either a leak at the transmission output seal or the final drive input seal. These are known problems.

You can check the final drive lube level easily by removing the fill plug and looking in. The lube should be close to the bottom of the threads of the fill hole.

This is not an emergency and you can continue to ride. Generally the leaks are reported to be slow. It would be a good idea to make sure the lube level in both the tranny and final drive isn't too low, but it is unlikely to be very low. You can get an idea of how much fluid has leaked out by seeing how much you get when you loosen the rubber boot.

Ultimately, if you are not a DIYer, you'll need someone to determine if it is the FD or tranny that is leaking and replace the seal.

HTH
Just back from checking things out. Here's an update:

1. I removed the band and checked inside the boot. There was the equivalent of maybe 1-2 DROPS of pale yellow oil inside the boot. I didn't think about checking inside the swingarm itself. Do I need to do that? I replaced the band and cleaned everything up so I can keep a better eye on it.

2. The oil inside the boot has to be transmission oil, because I have not seen this oil before, and I have not changed the transmission oil before. I do my own FD gear oil changes and I use Mobil1 - which is pink, sort of.

I'm due for a 12k service, which I'll take to the dealer (because of the valve check). I assume this repair can wait for that to be done. Any idea how much (ballpark) replacing the seal will cost?
 

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2005 K1200LT
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I had it done under warranty back in 2006 for $234.25 charged back to BMW. We can do a Tech session at Iron Horse if you want. I'll bring the tools and a seal. Just have to pull the drive and then the swing arm. Just like for a weep hole. Go watch the videos at the top of the page. Takes about an hour and a half.
 

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Howard - I believe what you have a rear trans seal leak. Normally rear drive leaks like you
stated will show the color of your rear drive fluid barring the fact that significant gear wear
could make the red rear drive fluid look very dark. Seal leaks on transmissions with such
low mileage are not all that common.

However with such a small amount showing up in the leak path in my opinion you could ride
the rest of the fall without a worry - so long as you check the fluid!! Maybe replace the
transmission fluid with Royal Purple and then look to see for that color to show!!

By the way just for my information are you running synthetic oil in your transmission?
 

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Discussion Starter #12
jzeiler said:
I had it done under warranty back in 2006 for $234.25 charged back to BMW. We can do a Tech session at Iron Horse if you want. I'll bring the tools and a seal. Just have to pull the drive and then the swing arm. Just like for a weep hole. Go watch the videos at the top of the page. Takes about an hour and a half.
That's good news regarding the repair cost. I didn't think it would be a huge bill, but it's nice to have that confirmed.

John, if you have the time and the desire to do this repair a week from today at the Iron Horse Lodge all I can say is "yes, please". Bring all the stuff you need; I'll stand nearby and nod appreciatively. :) The only full day I'll be at the Iron Horse is Saturday. Of course, if you wanted to do it Friday evening after I arrive that is your call, too. And if you determine you can't do it after all, that's fine, too. I'll get 'er done at Mathias BMW.

I'm out the door in a bit; on the way to Cleveland. Thank you.

While I have the floor, let me also say thanks to Dave Selvig (Saddleman) for calling right away after reading my original post. I appreciate that, Dave - and the rest of you guys for the assistance.
 

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Discussion Starter #13
dfinazzo said:
Howard - I believe what you have a rear trans seal leak. Normally rear drive leaks like you
stated will show the color of your rear drive fluid barring the fact that significant gear wear
could make the red rear drive fluid look very dark. Seal leaks on transmissions with such
low mileage are not all that common.

However with such a small amount showing up in the leak path in my opinion you could ride
the rest of the fall without a worry - so long as you check the fluid!! Maybe replace the
transmission fluid with Royal Purple and then look to see for that color to show!!

By the way just for my information are you running synthetic oil in your transmission?
I'm thinking we can feel certain this is a transmission seal leak, as the oil I'm seeing is NOT the color of the FD gear oil I use.

I don't know if the trans oil is synthetic or not. Probably should know that, but I don't. The dealer's service department has been doing that for me. It's a pale yellow color, if that helps.
 

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John, I can send my seal replacement kit with Lee if it would help any. It has drill bushings for the trans seal & slave seal, removal tools & correct depth installation tools. It also has spare seals.

The drill bushings make it easy to drill the hole in the center of the seal for the screw used to remove the seal.
 

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Wrencher Extraordinaire
2005 K1200LT
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Might as well send them along. I am using a Timken 25x40x7 now for the rear tranny seal as it has a more robust sealing lip than the stock one. I have also made up insertion tools but I never thought about the removal drilling guides - brilliant.
 

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Re: Final Drive - Small Oil Leak

hschisler said:
Let's talk final drives. I was washing my '09 K1200LT (29k miles on it) today and noticed a shmear of dirty sludge/oil on the bottom of the unit, centered around where the black rubber "boot" is fastened with the metal band. I ran my hand across it; there are no drops waiting to drip off or anything, but there's an area of black goo that is thickest at the bottom-most point of the metal band.
Mine has been doing much the same for a year or so now. I just keep cleaning it up at each washing. I use Castrol gear lube in both tranny and FD so I can't tell for sure which is leaking. I checked the transmission fluid after about 5,000 miles of leaking and the oil came out the threads slowly when I removed the fill plug. That is how I filled it at the last change so it didn't appear that the tranny has lost much oil.

I can't be as sure for the FD as I replaced it using only 220 cc per Tom Cutter's recommendation. He says that filling to the threads (which is about 250 - 260 cc) often causes seal leakage. So, since the oil is a half inch or so below the fill hole it is harder to tell if it has dropped. However, it didn't appear to have dropped much.

A few drops of gear oil will cause quite a mess. I may pull my FD this year just for a look see and to try out my new modified socket, but then again, I may just keep riding it and cleaning it up until the leak gets bad enough to be a danger to the brake. As it is now, it takes about 500 miles to completely coat the torque arm mount on the final drive so I just wash the bike every couple of weeks and mostly ignore it.
 

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saddleman said:
John, I can send my seal replacement kit with Lee if it would help any. It has drill bushings for the trans seal & slave seal, removal tools & correct depth installation tools. It also has spare seals.

The drill bushings make it easy to drill the hole in the center of the seal for the screw used to remove the seal.

That drilling guide is AWESOME...has to be the cats meow for us crooked drilling folks.
 

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Discussion Starter #18 (Edited)
This is interesting stuff. I feel like I'm sitting in on a medical school lecture; I've heard some of the terms before, I know where some of the things are, but I've never seen them or inside of them, or understand how they work together. Anyway...

We got back from Cleveland just awhile ago. 340 miles round trip. At a gas stop halfway there, I looked at the bottom of the swing arm. Completely dry. Same thing after arriving at our destination. And, I just looked at the bike now and it's completely dry. Except for checking it when we were stopped, I didn't even think about it - thanks to the piece of mind from the first series of posts and conversations with John and Dave.

It's been 5 weeks since I washed the bike - it was on 9/3/12, the day after I got home from CCR. It must take that much time for enough leakage to occur - and the subsequent accumulation of dust and dirt - that I notice it.

Now the bad news. As I was looking at this just now, I noticed a drop of oil at this location; it's the same pale yellow color that I noticed inside the rubber boot at the aft end of the swingarm. Notice, also, the oil collected on the centerstand. What does this mean...?



Here's another photo, from a different angle (a little out of focus):

 

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Your output seal is right above that, I would say that is the culprit that is leaking, get it taken care of at the fall reunion by John. Not a huge job,
 

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Mike is correct Howard. This just helps confirm the leak is where we thought it was. In fact that is the only place it showed up on my bike @18K when I had it done under warranty.
 
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