Gearbox & Diff Oil Leaking.

[Tweaky]

Just throwing a quick question out there bout Gearbox & Diff oil leaking. Just got these two areas of my skyline serviced by a workshop & now after the service has been carried out both of them are slightly leaking. Both were not leaking before i got them serviced & now leaving puddles of oil on the garage floor. Could it be they have over filled both areas & over a period of driving both will stop leaking ? Have checked all filler & drain plugs on both of them & all are tightly done up. The oil on the ground is a nice clean oil , so least that part they have done right !!

[Moodles2]

It's possible they were overfilled and what's on the ground is just from the breathers

[mad082]

yeah could be from breathers, or it could possibly a bit of spilt oil from when they were filling them. maybe get under the car and give the gearbox and diff a good wipe down with a rag to get any excess oil off and see if that makes a difference.

[Tweaky]

Have been under the car & wiped both gearbox & diff . Still both are leaking but my main concern is the gearbox , diff is getting less amount on the ground now. Do the breathers sit at the top of the gearbox near the bell housing ? When under the gearbox i noticed the oil was leaking from the bottom , where there is 4 bolts. 3 out of the 4 were tight but the bottom one was loose. So i tightened it up , but then it loosened off again. So that one bolt has been stripped inside the gearbox & can't get full lock onto it . That's where the oil is dripping from , also looks like it tightens upto some sort of gasket which where the gearbox bolts onto the back of the engine. If i drill it out & retap a new thread in there , so i can tighten the bolt back onto the gasket. Then do u think that will stop the leak ?

[mad082]

can't hurt to try. also just see if you can get a longer bolt the same size. you may be able to get it to tighten up without having to retap it or anything like that.

[Tweaky]

can't hurt to try. also just see if you can get a longer bolt the same size. you may be able to get it to tighten up without having to retap it or anything like that.

I'll pull the bolt out take it down the street & get a longer one. Hopefully with a bit of luck it will tighten as u said. If not then will have to retap a new thread in there . Thanks for the suggestion

[ARTZ]

measure the depth of the hole before you stick longer bolts in there. It may the bolt is too long and that is why it wont tighten up properly

there shouldnt be any oil leaking where the gearbox bolts to the engine as that could been your rear main seal is shot and its engine oil thats leaking not gearbox oil..

Often dirty old oil will gum up and block leakages, sometimes replacing and cleaning it will cause it to leak again..

This happens alot when people clean their dirty old engine of oil and gunk and find all sorts of leaks that weren't there before.

New thin oil will leak alot easier than thick dirty old oil, so it could be that the leaks were there already but the problem was masked by thick gunky old oil

Edited December 16, 2010 by Arthur T3

[Tweaky]

measure the depth of the hole before you stick longer bolts in there. It may the bolt is too long and that is why it wont tighten up properly

there shouldnt be any oil leaking where the gearbox bolts to the engine as that could been your rear main seal is shot and its engine oil thats leaking not gearbox oil..

Often dirty old oil will gum up and block leakages, sometimes replacing and cleaning it will cause it to leak again..

This happens alot when people clean their dirty old engine of oil and gunk and find all sorts of leaks that weren't there before.

New thin oil will leak alot easier than thick dirty old oil, so it could be that the leaks were there already but the problem was masked by thick gunky old oil

The problem after all wasn't the gearbox leaking oil , so u were right on that one ! Thank god also it wasn't the rear main seal either , big job to fix that one ! It was the driver side rocker cover which wasn't tighten down enough where the oil was leaking from. Was leaking at the back of the engine , running down onto the bell housing & dripping off the gearbox. All we did was tighten up the screws on the cover ( got a couple of turns out of the back ones ) & so far oil has stopped leaking.

[ARTZ]

The problem after all wasn't the gearbox leaking oil , so u were right on that one ! Thank god also it wasn't the rear main seal either , big job to fix that one ! It was the driver side rocker cover which wasn't tighten down enough where the oil was leaking from. Was leaking at the back of the engine , running down onto the bell housing & dripping off the gearbox. All we did was tighten up the screws on the cover ( got a couple of turns out of the back ones ) & so far oil has stopped leaking.

thats good news, common problem too ..mine did it as well but not that bad..

I ended up taking the covers off for painting anyway and putting some goo on them while at it..

what happened with the bolt

Edited December 18, 2010 by Arthur T3

[Tweaky]

thats good news, common problem too ..mine did it as well but not that bad..

I ended up taking the covers off for painting anyway and putting some goo on them while at it..

what happened with the bolt

We end up just leaving the bolt as is . It is still bolted in just not as tightly done up as the other 3 bolts . Can't undo by hand & still firmly in the gearbox. The mechanic said the bolts were only there to hold up a guard on the gearbox & wasn't a big issue. If leak starts up again will take off the cover put a new gasket on it , with some new rubbers washers for the screws also. But all is still good so far

[mad082]

yeah oil leaking from the rocker covers and from the power steering pump both seem to be factory optioned oil leaks. i have seen so many skylines with leaks from either of those 2 locations you can only assume it was an option box on the factory order form, LOL.