Gearbox oil leak inside drive shaft flange

Hello

Took the drive shafts off my gearbox last week. Drivers side was okay, dried up grease, passenger side was a black oily mess!

I've read this is gearbox oil leaking from the drive shaft flange into the drive shaft joint.

Some people say I just need to replace the flange seal inside there - but I am confused, as if gearbox oil is leaking from the seal inside the drive shaft, doesn't that mean there is another leak further in?

Can I get away with just replacing the drive shaft flange seal, or do I need to dismantle the entire thing?

Read this guide here, but it doesn't quite cover which bit could be leaking.

020 Flange

If it's leaking inside the drive shaft then it will be this seal that has gone - http://www.brokevw.com/pic%20203s.jpg
If the main flange seal was leaking you'd see it coming out where the flange goes in to the gearbox. Replacing the inner seal is pretty easy to do.

paceman said

If it's leaking inside the drive shaft then it will be this seal that has gone - http://www.brokevw.com/pic%20203s.jpg
If the main flange seal was leaking you'd see it coming out where the flange goes in to the gearbox. Replacing the inner seal is pretty easy to do.

Fantastic, you've reassured me immensely! Fingers crossed I can get it done!

The hardest part of replacing the inner seal is getting the drive shaft out of the way to get to the seal.
Sharp screw driver and either leaver the old seal out of stab the seal and lever it out.

Good time to also upgrade the gearbox oil to fully synthetic. Just make sure you can remove the filler plug on the side of the gearbox before draining any oil out of the gearbox.

Gearbox oil I've been using for a few years now.
 2 bottles/ 2 litres is plenty.

https://www.eurocarparts.com/p/triple-qx-ep-75w90-transmission-fluid-fully-syn-1-litre-522776022

I've found the best way to get the driveshaft out the way is to seperate the bottom ball joint and the steering ball joint off the hub and then you can swing the suspension out. If you undo the trust from the hub you'll have to get the camber re-checked. If you only touch the ball joints, you won't have that issue.
Drive shaft bolts are a pain - nearside you can get to through the wheel arch, but offside is a different story (unless you have a really long extension bar!). Make sure you clean out the splined bolt heads well or you'll end up stripping them when you can't get the spline drive in all the way.