Author Topic: Which is the BIS gearbox oil filler hole? (Read 2601 times)

petal · « **on:** October 07, 2006, 03:11:42 PM »

I removed this hex-header 13mm bolt, thinking it was the filler hole, ( high up on gearbox, right side in front of the half-shaft. top-centre in photo)

But then I noticed a rather damaged-looking square-headed bolt (1/3 way up the gearbox, right side, to the rear of the half-shaft. bottom-left in shadow, rather out of focus)

I can't find a clear picture/statement in the BIS CD-manual as to where/what the filler plug is.

I'm inclined to think it's the square thing. Do I need a special tool for it? What is the other bolt for? (have I undone something inside the gearbox by removing it? I hope not...)

Thanks,
Bill

petal · « **Reply #1 on:** October 07, 2006, 03:50:41 PM »

Another thought:

What if the lower bolt is the filler hole, which also marks the level, but I can't get it out?

Can I fill the box through the upper hole, with a measured volume of oil as specified in the manual? I suspect that this is risky, as each gearbox case is a little individual so the capacity will vary and overfilling can be harmful. Is that so?

ChrisRLewis · « **Reply #2 on:** October 07, 2006, 11:23:59 PM »

Not sure if it's the same on the Bis but here is an aircooled box

petal · « **Reply #3 on:** October 08, 2006, 09:24:38 AM »

Thanks, it's clearly the lower square bolt.

Now I'm a bit worried that removing the upper hex-headed bolt I've given myself more trouble...

I tried a reversed 1/2" square drive on it, but it didn't fit. I'll try to buy a special tool, and if that doesn't work out I'll have to make one.

Ta,
Bill
Bristol

banjomandolin · « **Reply #4 on:** October 08, 2006, 10:41:20 PM »

You are lucky the square plug is not more mangled. Don't know what you mean by "reversed" 1/2" socket. I always use the 1/2 socket. You may have to hammer it on or file a bit off the plug. It helps if you use a long extension.