Drain plug seepage

[RAMBLIN RED]

I have had some transmision drain plug seepage on this R11RT since I purchased it, not much, just enough to get a whiff of burning oil when I stop. Had the right side tupperware off today, removed the foot peg bracket/silver thingy and verified all the seepage is at the drain plug. I always use a new crush washer when I change trans oil and torque to 17 lbs. My first oil change revealed no crush washer,Iadded one. Now, reading a maintenance file from Internet BMW riders, I find that "newer" R11RTs didn't need crush washers. I doubt that anything on my bike could be considerd "newer" since production date is listed as 4/96 but it does leave me questioning if the crush washer is the cause of the seepage? Between changes (12k)the oil level drop is less than 1/4" so this isn't a big deal, but I would enjoy this thing more if it stunk less.

 

[Skywagon]

I certainly don't know, but perhaps this diagram and link can help you decide. I am sure someone who does know will weigh in soon. Give it a minute to load the picture on the bottom right hand side of the page.

 

 

https://www.ascycles.com/Illustrated_catalog2/MicroList.aspx?id=51680&bindName=5-gear_transmission&bindCat=23_0279

 

[RAMBLIN RED]

Thanks David, I have seen this and continue to use a crush washer. Don't know why I have this seepage. Actually the crush washer didn't change anything, I seeped before the washer and after. As long as it doesn't get any worse I see it as a minor smelly nuisance

 

Uh, I think I answered my own question about the crush washer

[Selden]

Wrap the threads with teflon tape, and use a crush washer.

[RAMBLIN RED]

Wrap the threads with teflon tape, and use a crush washer.

 

good idea...I'll try it

[Jim Moore]

I think the 23 nm (17 ft-lb) spec is wrong. I think it's supposed to be 32 nm, like the oil drain plug. The numbers got transposed in the manual and it's been wrong ever since. In my experience 23 nm frequently isn't enough to crush the washer.

[Trullion]

According to Haynes up to the early 1996 models the torque is 23nm; late 1996 onwards it is 30nm. My late 1995 (1996 registered) 1100RS has no crush washer on the drain plug. The 2000 850GS I owned from new did have a crush washer and the design was lightly different to accommodate it. I believe that oil seepage at the plug is the result of using the wrong torque for the type of plug fitted (i.e. washer or washer-less). 23 and 30 don't transpose and I've seen the same torque values quoted in more than one source. Seepage at the drain plug is not uncommon on the 1100 and 850s.

[Trullion]

Sorry, forgot to add that the 23nm applies to the earlier washerless plug, so it wouldn't be sufficient to properly tighten the later type with the crush washer.

[Jim Moore]

That's interesting. i've enver seen "30 nm" referenced anywhere. I've only seen 23 nm. Maybe I had an old manual.

 

Edit: I just checked my R1100S manual. It calls for a crush washer and 23 nm. I'm sure it's wrong. It's either left over from the non-crush washer spec, or the numbers are transposed. Either way, I think it's supposed to be 32 nm.

[Trullion]

The information I quoted was for the 5-speed 1100RS, RT, R and GS, not the 1100S which has the later 6-speed box. I believe the 1100S plug needs an allen key to remove it (I could be wrong as I've never owned one) whereas the earlier ones like mine need either a box spanner or socket (13mm). That said, I got my latter post the wrong way round (too much Xmas booze). The earlier plug has no washer and the torque setting is 23nm. The later (late 1996 onwards) is 30nm and has a washer. FWIW the engine oil drain plug tightening torque is quoted as 32nm. Clymer only quotes 23nm for the gearbox drain plug torque irrespective of year, but I believe that this is incorrect.

[Gary S]

I'll tell you what my experience has been. I have a 1999RT and the manual has the higher torque for the newer models. But when I use the higher torque the washer deforms and the plug leaks. So I use the lower setting. But I also use little grease on both sides of the new washer to keep it centered on the plug while torqueing. I have not had a leak since.

[Trullion]

I'll tell you what my experience has been. I have a 1999RT and the manual has the higher torque for the newer models. But when I use the higher torque the washer deforms and the plug leaks.

 

well, I suppose it would. The later bikes have a washer-less plug that should be tightened to the higher torque (30NM). The recommended torque for a spark plug with crush washer is 20NM, so tightening the drain plug to 30NM with a washer fitted could well deform it and cause a leak. I've never has a leak on my RS with the earlier plug and washer torqued to 23NM or on my 850GS with the later washer-less plug torqued to 30NM, in both cases as per Haynes. Simples.

[Gary S]

Well there appears to be some confusion as to whether the plug takes a seal or not. My Haynes manual has the two different torques and states late 96 and up have no washer. But my BMW manual shows the drain plug with a seal and the lower torque. I guess the main point here is to achieve a good seal. On my first gearbox oil change it had a washer and no leak so I continued with the washer.

[RAMBLIN RED]