Series 3 selector shaft O-ring oil leak and a nasty surprise!

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Simon Perks

Active Member
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Location
Switzerland East
Decided to check the gearbox oil level this evening as I have the standard gearbox selector Oring leak.
removed the fill plug and using my squeeze bottle and tube put a good half liter of EP in until it started to drip out.
Then i decided to check on the rear transfer box, removing the filler plug and expecting as previously to have to top it up too I was shocked to be met with a torrent of oil and i mean almost 3/4 of a liter!!

Now i seem to recall that the process is the same as the gearbox, land rover on the level and fill until it starts to drip from the filler plug and your good to go ..right?

Is this indicative of a leak between the gearbox and the transfer?
Would you drain the transfer completely and then put the two and a half liters back in?

On another note i was also thinking i will have to replace the rear main oil seal as there is a bit of a drip from the bottom of the transmission brake drum in the last month or so...

I would be grateful of an advice here.

Simon up the Alp
 
Decided to check the gearbox oil level this evening as I have the standard gearbox selector Oring leak.
removed the fill plug and using my squeeze bottle and tube put a good half liter of EP in until it started to drip out.
Then i decided to check on the rear transfer box, removing the filler plug and expecting as previously to have to top it up too I was shocked to be met with a torrent of oil and i mean almost 3/4 of a liter!!

Now i seem to recall that the process is the same as the gearbox, land rover on the level and fill until it starts to drip from the filler plug and your good to go ..right?

Is this indicative of a leak between the gearbox and the transfer?
Would you drain the transfer completely and then put the two and a half liters back in?

On another note i was also thinking i will have to replace the rear main oil seal as there is a bit of a drip from the bottom of the transmission brake drum in the last month or so...

I would be grateful of an advice here.



Simon up the Alp

The oil is running past a worn output shaft seal on the main box, and overfilling the transfer box.
You can go on for a while draining the excess out if the transfer box, and replacing it in the gearbox.
But in the long term, it would be better to replace the faulty seals in both boxes
 
The oil is running past a worn output shaft seal on the main box, and overfilling the transfer box.
You can go on for a while draining the excess out if the transfer box, and replacing it in the gearbox.
But in the long term, it would be better to replace the faulty seals in both boxes

A big job or a saturday morning escapade?
 
A big job or a saturday morning escapade?

Depends on how skilled you are, and how good your tools are, all sorts of variables.

It is years since I have done it, but from memory you don't have to dismantle the gearboxes, but you do have to remove the handbrake, and the transfer box from the back of the gearbox.
I could be wrong, though, it is decades since I had a series.
 
Your transfer box output leak may subside now the oil level is not so high.

but i guess it's just going to fill up again ...
However as I was a mechanic (citroen) in my previous life .. like i did my apprenticeship in the 80's & re built the engine on this when i first got it, i'll give it a go ..
 
I'm not sure, I overhauled my gearbox and I'm pretty sure I changed this seal but I didn't split the box and transfer box. You have the top cover and the big hole where the overdrive would go and I think there may be enough space to get to it. I think getting the old one out will be the hardest part. I need to look at the manaul and referesh my memory
 
I'm not sure, I overhauled my gearbox and I'm pretty sure I changed this seal but I didn't split the box and transfer box. You have the top cover and the big hole where the overdrive would go and I think there may be enough space to get to it. I think getting the old one out will be the hardest part. I need to look at the manaul and referesh my memory

Removing the transfer box isn't a huge job anyway. Removing the handbrake is a very fiddly job, after doing that, the transfer box will seem like a pleasure.
 
I've never really understood why this seal seems to fail. If I was an oil seal this would be my position of choice, oil both sides of me, no pressure to deal with and only modest temperatures.
 
I've never really understood why this seal seems to fail. If I was an oil seal this would be my position of choice, oil both sides of me, no pressure to deal with and only modest temperatures.

Gearboxes do have a certain amount of pressure in them, and a certain amount of heat, both caused by the stirring of the oil by the gears.
And the oil in those is fairly thick so will generate a bit more pressure and heat than some.
 
Series gearbox shouldn't have any pressure in it, its vented to atmosphere, If I had a hole in my tyre the size of the vent hole in the gearbox it would flat in no time, surely the only positive pressure in the gearbox comes from the slow increase in temperature.
 
Some times its not the seal but the bearing carrier in the alloy casing letting oil past.
The seal can be got at from the rear attached pic shows the shaft with out the gear on viewed from the rear the seal is behind the slpash plate which ahs the running surface on for the seal.
Maybe possible to get the seal out and renew but not easy.
 

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I'm more sure it can be done in situe. You would need the fancy castellated spanner, lock washer 217476, the spacer the seal runs on 502482 perhaps the flinger 212415 and the seal 236305. I seem to recall the flinger is pressed onto the spacer and they come out as one peice, but its easy to bend the flinger and it then gets loose on the spacer. Also it may be leaking because the spacer has a wear groove. The whole lot is under £20 even if you buy the "de-lux" seal. Only expensive bit is the fancy spanner. Get an old small screwdriver, heat it and bend the last 5mm over to 90 deg. With the spacer out you will have get inside the seal to pull it out.
 
Series gearbox shouldn't have any pressure in it, its vented to atmosphere, If I had a hole in my tyre the size of the vent hole in the gearbox it would flat in no time, surely the only positive pressure in the gearbox comes from the slow increase in temperature.

If someone played a hose on you, you would feel pressure, even though you would be standing in the open atmosphere.

The oil in a gearbox is the same, it is sprayed around by the moving gears.
 
If someone played a hose on you, you would feel pressure, even though you would be standing in the open atmosphere.

The oil in a gearbox is the same, it is sprayed around by the moving gears.

I don't think you are feeling pressure, its the force you are feeling. Once the water has left the hose there is no pressure.
 
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