What am I leaking?

Willy · Post by **Willy** » Wed Sep 14, 2011 2:34 pm

Whenever I park up after a decent drive, I seem to get a very small puddle of fluid appear under my gearbox end. Maneuvering the car in and out of the drive and playing with the suspension doesn't produce this elusive fluid - even after being parked up for 24 hours, it only seems to appear after a long ride out. Judging from whereabouts the leak originates (see pictures) - I reckon it's gearbox oil - caught some on the end of my finger and it took alot of soap to get the greasiness off. How can I check the fluid level? It's a 1991 XU5S and the Haynes helpfully just says "there's a filler/level plug on the gearbox end cover"...

The leak is only directly under the gearbox end cover (see where it looks "wettest"

The diff housing also looks "wet" but there was no leaking underneath here.

As did the accumulator sphere area, but again no evidence of leaking underneath, and the reservoir was at "max" (in high with engine on) so I ruled out an LHM leak

And finally a slightly better pic of the transmission end - maybe when the oil has warmed up it's thin enough to escape through a loose screw? Really have no idea...

Cheers, Will

rmattila · Post by **rmattila** » Wed Sep 14, 2011 3:22 pm

Looks like a slightly leaking gearbox end cover seal - might get better just by tightening the bolts slighty, if you're lucky.

Unscrew the bolt to the left of the center point of the first picture, and fill through the breather cap until it starts leaking from the hole of the removed screw. Measuring the amount needed to start the overflow, you know how much shortage there was.

Post by **Defender110** » Wed Sep 14, 2011 3:34 pm

rmattila wrote: Unscrew the bolt to the left of the center point of the first picture, and fill through the breather cap until it starts leaking from the hole of the removed screw.

I thought the level plug was the one on the right of the last picture?

Gibbo2286 · Post by **Gibbo2286** » Wed Sep 14, 2011 3:41 pm

Defender110 wrote:I thought the level plug was the one on the right of the last picture?

It is.

citronut · Post by **citronut** » Wed Sep 14, 2011 6:12 pm

mine you only use BV spec gear oil,

the leak could be the level plug copper washer needs replceing, as it does look wet/oilly on to of the lip of the end cover just below the level plug,

i think if it were the end cover gasket lealing it would not go up over that ledge/lip,

regards malcolm

Willy · Post by **Willy** » Wed Sep 14, 2011 6:18 pm

Thanks people.

It only leaks after the car's been driven some distance, then it'll stop. Strange. I'll try and get it over the inspection pit in a couple of days to check the fluid level/bolts.

rmattila · Post by **rmattila** » Thu Sep 15, 2011 5:09 am

Defender110 wrote:I thought the level plug was the one on the right of the last picture?

That is correct. I've apparently been filling my gearboxes for the last 15 years based on wrong information regarding the level plug. No problems have been caused be that, however, even though I usually drive the boxes to 700 000 km or more, so I guess a slight difference in gearbox oil level is not a big problem, as long as it keeps the oil inside and the level does not drop.

But yes, it's better to use the plug actually meant for level control (if your box is new enough for that to exist, that is).