gearbox oil leak

[ericcs]

i need to change the inner cv boot on the passenger's side. is it normal for gearbox oil to leak from a split boot, i thought the flange was sealed fro the box?

[sports racer]

There shouldn't be any leak but you might have some oil that's seeped out over the years.

Give the flange a wipe down and see if it's leaking. If it is you've got a problem.

[ericcs]

the boot's torn completely round, and there is no grease at all, just a pool of oil!

[gldgti]

well not quite true, there is an oil seal on the inside of the gearbox driveshaft flange, and these can pretty easily be damaged by over-compresson of the inner cv joint - the end of the driveshaft will punch into the seal and thats it. You can get these easily and cheaply.

Also, over a long time, some greases will decompose and the lighter oils which are normally trapped in the grease can seperate out. See this plenty of times, you open up a cv boot and you get a pool of oil and some thick black/brown gunk (thicker than normal grease). I'm pretty sure if you use proper cv joint grease this doesnt normally happen, but a lot of people think grease is grease.

Whenever I take out a driveshaft, I always make sure to check the inner seals for damage and change them if necessary. They are so cheap I keep a stock of a couple just incase.

[ericcs]

thanks for the info. so if i drop the drive shaft, will it be obvious to see if the seal has been damaged?

[sports racer]

If they are anything like the ones on my MK2 it should be easy to see. Wipe off all the oil and grease and look for any damage. The seal is a large metal cap with rubber around the edge and a press fit. Might be different though, 1 of the 4 I've taken off today was a metal cap that was screwed on, needed an allen key to take it off and it was so tight I gave up.

[ericcs]

thanks paul, just have to work out how my son gets the jack under the car, the sump is only 50mm of the ground

[ericcs]

well, iv'e taken the drive shaft off. when i removed the 6 screws and pulled the shaft back, a heap off gearbox oil dripped out.
there is absolutely no sign of grease ever being in there, so can only assume it was full of oil. the cap is on the inside of the flange.
beats me how, if it was filled with oil, how they got it in there?

[roccodingo]

New CV boot and 90 G of moly disulphide grease then pop it back in. Check the outer joint for lube and boot condition and do it while you got the assembly out.
Be done by morning smoko .....................................whats next ??

[ericcs]

New CV boot and 90 G of moly disulphide grease then pop it back in. Check the outer joint for lube and boot condition and do it while you got the assembly out.
Be done by morning smoko .....................................whats next ??

thanks, you answered my next question on how much grease to use!
still can't explain why it was full of oil and no grease?

[Guest001]

thanks, you answered my next question on how much grease to use!
still can't explain why it was full of oil and no grease?

Possibly because driving with a torn boot has spun all the grease out and only the oil leaking through the gearbox seal is left. Is the usual reason if you dont find it quickly

[ericcs]

Possibly because driving with a torn boot has spun all the grease out and only the oil leaking through the gearbox seal is left. Is the usual reason if you dont find it quickly

the boot has only torn in the last couple of months. initially i didn't notice it as no grease flicked out, like a typical torn boot would produce, only oil, which i thought was coming from somewhere else. hopefully this is not still the case.

[Guest001]

the boot has only torn in the last couple of months. initially i didn't notice it as no grease flicked out, like a typical torn boot would produce, only oil, which i thought was coming from somewhere else. hopefully this is not still the case.

Doesnt take long would do it in one trip of an hour or so Or did in mine once Could also have had the oil leaking into it which stuffed up the grease and it looked like oil when it came out.

[ericcs]

can oil leak out past the cap on the flange, and does it need to be removed to remove flange incase it's the flange seal that's leaking?

[ericcs]

looks like the flange seal was damaged from a previous removal
$15 genuine, took some finding!