1100 Gearbox Drain Plug?

[ThreeDawg]

Just changing the fluids in my 97 1100GS and didn't notice a washer coming out with the gearbox drain plug. Is the one I have the later revised 'washerless' one, and if so, am I right in thinking that the torque setting for this type is higher (circa 30Nm rather than 23?) than the ones with a crush washer? The Haynes manual doesn't seem to mention a washerless type.

 

[MattW]

Looks like the normal plug that takes a crush washer to me (although I stand to be corrected).

Are you sure there's not a crush washer stuck to the gearbox casting?

 

[ThreeDawg]

Doesn't seem to be. I'll check, although the outer face of the case where the drain hole is isn't flat. Hum, this will need another picture. Bear with me...

 

[ThreeDawg]

Don't think it's a washer...

 

[MattW]

Don't think it's a washer...

That looks very much like a crushed crush washer to me. If you can make some sort of right angled pick you should,be able to tease it out.

 

[Bryn]

Small screwdriver, give it a tweak

Edit: Matt beat me to it

 

[ThreeDawg]

Hmm, well of course my first thought was washer, so I tried to pop it out with a small screwdriver, but no go. I'll give it a go with a right angled pick.

 

[ThreeDawg]

Have to say, if that's a washer in there then it's pretty firmly attached to the gearbox case. Made a pick to try to hook it off from inside, no dice, and a screwdriver on the outside (gently) won't shift it either.

 

[maikhoepfel]

Stupid questions, aren't the washers copper and should be easy to spot? But I guess if you haven't had any leaks, I'd leave it as-is and check it every now and then.

 

[ThreeDawg]

No, the ones from BMW seem to be made of aluminium. I have changed the oil in this bike before and can't remember if there was a washer present- before that it was done at a dealership.

I am beginning to think mine has the washerless type- reckon I'll do as you suggest- nip it up and keep an eye on it.

Still like to know if it should be tighter than 23Nm though.

 

[MattW]

Stupid questions, aren't the washers copper and should be easy to spot? But I guess if you haven't had any leaks, I'd leave it as-is and check it every now and then.

Annealed (so they 'crush') aluminium.

Looking at the picture 'down the hole' and the removed plug, you can see where there's a little step in the crush washer which corresponds with the sealing face of the plug.

You could just refit the plug and carefully tighten by hand. Many people reuse crush washers even though the official guidance says you should use a fresh one each time. However if you do, the factory torque settings are meaningless - you must tighten by hand. What you shouldn't do is use another washer - it won't seal against the existing one. A turn of PTFE or a smear of Heldite will help the plug seal against the pre crushed in-situ washer.

However, I'd either make or get hold of a long hooked (or right angle) pick and hook the washer on the inside edge. Might take a few attempts though...

 

[ThreeDawg]

Looking at the 'washer' down the hole- even if it was annealed aluminium it would be hellishly crushed to get that shape. I made a very sharp pick and couldn't shift it.

The shape of all the other drain plugs is completely different- doesn't have the conical bit below the head at all, just basically straight like a short bolt.

Also, the washers have straight sides- the raised bit around the outer edge of the 'washer' in the pic is at about a 45 degrees angle.

 

[MattW]

Looking at the 'washer' down the hole- even if it was annealed aluminium it would be hellishly crushed to get that shape. I made a very sharp pick and couldn't shift it.

The shape of all the other drain plugs is completely different- doesn't have the conical bit below the head at all, just basically straight like a short bolt.

The conical bit will be to centre the washer before it starts to crush (the other plugs don't need this as they're not at the bottom of long close fitting tunnels) - you can see a little conical face on the inside of the washer in your picture. That said, yours has probably been over torqued and has expanded so that it has jammed against the inside of the recess (or the wrong sized washer has been used).

 

[Trullion]

That looks just like the plug on my 1996 1100RS. I have recently changed the oil on mine. As has been said, you usually get an aluminium washer, not a copper one (though I think I've had copper in the past). It is a bit fiddly to ensure that this sits centrally on the shoulder on the plug. My guess is that if it doesn't the washer gets squashed and "welds" itself to the casing. I used to have an 850GS manufactured in 2000. This had the later type drain plug, without the washer (as Haynes indicates). This needed to be tightened to 30nm rather than the 23nm for the earlier type with the washer. I believe that overtightening of the earlier type (ie to the torque of the later type) is the cause of occasional threads on the oilhead forums along the lines of "why is my gearbox leaking/" or "I can't get my drain plug out".

Hope this helps.

 

[ThreeDawg]

Thanks for all the replies. I fitted a new aluminium crush washer and torqued it down to 23Nm. I'll keep an eye on it and reinvestigate if it leaks- I really don't think there is a washer welded to the gearbox housing down there.