Author Topic: Oil leak underneath bike  (Read 8852 times)

Offline dfx

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Oil leak underneath bike
« on: December 21, 2014, 02:35:28 PM »
Hi,

1984 K100 120k km. I'm sure someone must've seen this, what is the likely reason for the oil? What is the unit covered in oil? The gearbox?
Thanks!
  • Alsace, France
  • K100RT 1986

Offline Scott_

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Re: Oil leak underneath bike
« Reply #1 on: December 21, 2014, 02:43:02 PM »
Most likely the clutch nut o-ring. Very common as a source of oil leakage as our bikes age.
The oil covered component is the "intermediate gear housing", and it also contains the clutch assy.
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1995 K1100LT 0302044
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Offline i-man

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Re: Oil leak underneath bike
« Reply #2 on: December 22, 2014, 12:56:20 PM »
would it be possible for you to post an exploded view of the part you're talking about? I have the same problem. i looked it up and didn't find a match for clutch nut o ring.

thanks

Offline F14CRAZY

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Re: Oil leak underneath bike
« Reply #3 on: December 22, 2014, 04:50:32 PM »


#17. Definitely want to go to the dealer for it as I tried using one from an auto parts store by eye-balling the old one and it leaked
  • Grand Rapids, MI
  • '87 K75C
'87 K75C w/ Pichler V1 fairing. LED's, CATZ driving lights, Audiovox cruise, LT top case, tons of other mods by Drake...


Offline dfx

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Re: Oil leak underneath bike
« Reply #4 on: December 22, 2014, 05:03:50 PM »
So it's the o ring at number 17? Is it engine oil or transmission oil that is leaking?
  • Alsace, France
  • K100RT 1986

Offline Scott_

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Re: Oil leak underneath bike
« Reply #5 on: December 22, 2014, 07:05:29 PM »
Yes, #17 is the o-ring that leaks. The oil leaking from a bad o-ring will be engine oil.
If you wipe your finger along the bottom and give it the sniff test, you should be able to definitely tell if it has the strong 'sulfur' odor of 90wt gear oil or not.

It is possible for gear oil to leak from the bell housing area, but less likely than engine oil.
  • My Garage
1995 K1100LT 0302044
2017 FLHTK Ultra Limited
1997 K1100LT 0302488 (R.I.P.)
1997 R1100RT ZC62149(sold)
"One who does not ask questions is ashamed to learn" Danish proverb

Offline Scott_

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Re: Oil leak underneath bike
« Reply #6 on: December 22, 2014, 07:16:18 PM »


IF, the oil has the gear oil sulfur odor to it, the most likely cause would be the clutch push-rod shaft seal. (#12 in this diagram seals the push-rod #13 in previous diagram)
  • My Garage
1995 K1100LT 0302044
2017 FLHTK Ultra Limited
1997 K1100LT 0302488 (R.I.P.)
1997 R1100RT ZC62149(sold)
"One who does not ask questions is ashamed to learn" Danish proverb

Offline Motorhobo

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Re: Oil leak underneath bike
« Reply #7 on: December 22, 2014, 09:30:06 PM »
would it be possible for you to post an exploded view of the part you're talking about? I have the same problem. i looked it up and didn't find a match for clutch nut o ring.

thanks

Exploded parts diagrams are on several dealer sites. I use bobsbmw.com because it's easy to navigate. Look here...

http://store.bobsbmw.com/microfiche/BrowseSeries.aspx


1994/1995 K75 ABS Frankenbike: original engine 136k miles, frame from Gary Weaver (RIP), 173k miles -- Current Odometer: 198k miles
1994 K75 since 2013, 82,000 mi (19k mine) w/California Sidecar Friendship II Sidecar & Black Lab 'Miss B' - RIP

Past: 1974 Honda 550/4 (first bike), 1994 K75 (sold), 1995 K75 ABS (parts bike), Sidecar Dog & Best Bud 'Bo' - RIP

Offline TimTyler

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Re: Oil leak underneath bike
« Reply #8 on: December 23, 2014, 12:01:01 AM »
If you choose to replace the O-ring there are other maintenance tasks worth performing at the same time.

Clutch -> Spline lube
Engine -> Rear Main Seal replacement
Clutch -> Friction disk (measure and replace if necessary)
Gearbox -> Tighten Grub Screw if lose http://www.motobrick.com/index.php?topic=4302.0

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