Gearbox drain plug washer NOT ????? Eh ?

kfrogzx7 · Post by **kfrogzx7** » Sun Mar 15, 2015 1:44 pm

Would those striations be designed to bite into the gearbox casing ? Still they'd only do that once even if that was the idea ?
What was BM's thinking if indeed this plug is designed to be used without a crush washer ?
BTW pics taken with my Defender phone , not too bad I thought ?

Corvus · Post by **Corvus** » Sun Mar 15, 2015 2:11 pm

It's a built in/moulded in seal. Probably high shore to add friction to the gearbox surface. Job done mate......

kfrogzx7 · Post by **kfrogzx7** » Sun Mar 15, 2015 2:36 pm

So you're confident I should just bung it back on and they'll be no leaks ?

Corvus · Post by **Corvus** » Sun Mar 15, 2015 3:38 pm

kfrogzx7 wrote:So you're confident I should just bung it back on and they'll be no leaks ?

Yes.

But look at it from a logical skeptics point of view.

Are we worried that if I'm wrong it will fall out? No.

Are we worried that if I'm wrong it might drip? Maybe.

So the worst case ain't so bad.

I'm as confident as I could be based on photos anyway.

kfrogzx7 · Post by **kfrogzx7** » Sun Mar 15, 2015 6:13 pm

Thanks Corvus, so the only question that remains is why did BM use this type of seal here and crush washers everywhere else, I presume they don't do things like that just to be contrary ?
It must have been a rational decision ?

nab 301 · Post by **nab 301** » Sun Mar 15, 2015 9:20 pm

The answer is in this thread , according to Blackal it's a twin anular ridge , either way I've never fitted a seal and it's never leaked in the 95k ish miles I've added to the odometer...
viewtopic.php?t=18250&postdays=0&postorder=asc&start=15

kfrogzx7 · Post by **kfrogzx7** » Sun Mar 15, 2015 10:19 pm

Thanks Nigel, that's enlightening.
I still wonder why BM chose this type of seal for transmission ?
and why such a large drain plug requiring such hefty reinforcement around the orifice in the bottom of the gearbox case ?

Corvus · Post by **Corvus** » Mon Mar 16, 2015 6:23 am

kfrogzx7 wrote:Thanks Nigel, that's enlightening.
I still wonder why BM chose this type of seal for transmission ?
and why such a large drain plug requiring such hefty reinforcement around the orifice in the bottom of the gearbox case ?

There could be a few reasons, but the most likely one I can think of is something along the lines: ok, we need a plug this thread size (to let the thick oil out) , we want a magnet in it (another reason for the large thread size) and we want a low profile head (probably the main reason for the large thread size) for ground clearance, Armed with that specification they go to outside suppliers and this one is available which ticks the boxes.

nab 301 · Post by **nab 301** » Mon Mar 16, 2015 10:14 pm

kfrogzx7 wrote:.
I still wonder why BM chose this type of seal for transmission ?
?

Is the transmission not by Getrag ?

Corvus · Post by **Corvus** » Tue Mar 17, 2015 6:38 am

nab 301 wrote:
kfrogzx7 wrote:.
I still wonder why BM chose this type of seal for transmission ?
?
Is the transmission not by Getrag ?

Just substitute "bm" for "getrag" then.

Found this:

http://www.largiader.com/tech/oiltrans/interview.html

Probably been on here in the past, but an interesting read for those, like me, who haven't seen it before.

nab 301 · Post by **nab 301** » Wed Mar 18, 2015 11:08 pm

Just substitute "bm" for "getrag" then.

Found this:

http://www.largiader.com/tech/oiltrans/interview.html

Probably been on here in the past, but an interesting read for those, like me, who haven't seen it before.

I've read that before but I think it relates to the 5 speed transmission , the article dates from '96