R32 Gtr Gearbox Leak

[Mike__]

Hey boyz,

For the past few months i've occasionally seen a drop or 2 of the smurfsblood oil on the floor of my garage. Wednesday night & a longish drive i think somethings let go because i lost a bit of oil. Jacked the car up this morning and hte entire underside of the box + some rear of the car has been sprayed with oil. Leak appears to be coming from up front on top where the box meets the bell housing. Also seems, but hard to tell its leaking out the small hole on the bottom where they meet.

Am thinking hte front seal of the gearbox is gone, & the clutch / flywheel is picking up the oil and throwing it out a vent up top?. The gearbox oil was changed just before i bought the car ~2yrs/6000km) ago so it cant be overfilled. Theres 2 pipes that run above the box. there both covered in oil but no oil internal, assuming one of these is a vent.

So just wanted to post on here incase theres something im missing to check. + have pulled a few boxes out in my time but am literally dreading this one so wanted to be certain be4 i get started...... By far my most favourite car ive owned but damm what a bit^* to work on.

Thanks

Mike

[2LV8ETR]

Does sound like the input shaft seal.

Have you checked to see whether the breather has disconnected or cracked where it joins to the gearbox? (not up on top of the bell housing)

These boxes aren't hard to drop man. With a mate and the right tools it should be in and out in 2-3 hours.

There is only one bitch of a bolt to get to and that's on top of the bell housing. If you disconnect the tailshaft and jack up the front of the engine, you can use a socket and 4 extensions to get to it without any issues.

[GTR1993]

On top near where the bell housing meets the block is where the breathers are, i had the same issue after i accidentally filled my transfer case full of smurfs blood after filling it through my shifter, not knowing it didnt go into the gearbox.

[Mike__]

yeh breather hose / 90deg outlet is in tact. Have all the right tools

thanks

[Mike__]

On closer inspection i followed the two venting tubes running along the top of the gearbox to the top of the bell housing / behind the rocker cover to where they vent. You can see fluid has been oozing out.

Thanks gtr1993, the previous owner can the oil changed before i purchased the car, never leaked a drop until a few months ago. now i bad

Atm i dont think the front seal of the gearbox is gone. Removed the filler bolt and no oil came out, so definetly not overfilled & a prior block in the line.

Car is up on the stands ready to drop the box, just a little unsure what the problem might be now. anyone got any ideas??

Thanks

Mike

Edited April 10, 2009 by Mike__

[SteveL]

There are 2 breather tubes, one for the gearbox and one for the transfer case. The transfer case uses (or should use) ATF, which is reddish in colour and has a distinct smell. From your description the fluid is definitely coming from at least one of the breathers, but if the gearbox is low in fluid it might be that the overflow is coming from the transfer case. Of course the car must be level when you check gearbox, etc.

Suggest you check that fluid levels are correct, thoroughly degrease the area, drive the car normally for awhile and recheck for leaks/overflow.

[Mike__]

Thanks for the response steve. I know the transfer case uses ATF but i didnt check if it had g'box fluid in by mistake, will check tomorrow. car is level for fluid checks. Still stumped as to what would cause the fluid to start spewing out all of a sudden, the car was driven lightly 2.

Its seen the strip & 2 mild track days with no fluid loss. Might refill and see how it goes. maybe the fluid level has been low, caused the oil to get hotter and vent out the tube?

[Mike__]

just checked transfer case. definetly ATF, & at the correct level. Drained it anyhow to replace

Drained the gearbox oil, ~2.7lts total. So i lost ~1.4ltrs out the overflow wed night, got me stumped to why it spewed out.

Going to replace the oil with some new stuff & see if it happens again.

Anyone have any ideas? i know these boxes have an internal pump drive, maybe something is wrong there......

thanks in advance.

mike

[SteveL]

The pump is in the transfer case and only circulates oil (ATF) within the transfer case. From your description there's no ATF mixed with the gearbox oil + the ATF level in the transfer case is correct, so I'd suggest that eliminates that transfer case pump as problem area. 1.4lts is a lot of oil, but it is assumed that the correct amount of gearbox oil was present in the first place (note: 2 years is a long time.....gearbox, etc oil levels should be checked at least once a year, but more often if your doing any trackwork with the car). In any event, at this stage I'd still suggest refilling to the correct level and then simply drive it to see what happens.

[Mike__]

Thanks steve.

Going to replace both diff fluids aswell as th xfer case whilst the areas are accessible

Report back here once i've had a chance to change + longish drive

Mike

[Mike__]

Just to give some conclusion to this thread.

changed the gearbox oil with castrol VMX (didnt want to fork out the $$$ for full synthetic syntrax incase it just spewed out again). Box feels better, as is always the case with changing the oil but everything feels firmer with the heavier 80 weight oil (OEM recommended) compared to the lightweight shockproof that was in there. Much prefer it.

Most important thing, havnt lost a drop of oil since

thanks to all those who replied

mike