Rear diff leaking !! Need advices

Hi guys
I was noticed my rear diff is leaking today when i wash the car , after i jacked the car up, its looks like the oil had spilled out from the fill plug bolt which facing toward the rear bumper , i had checked the drain bolt properly and there were no leak at all at the drain bolt which iam very worry about ! So my question now is does it leak because of any overfilled case ?? I just did my diff serviced about last 2000 km and my mechanic seem like he had pumped the full amount of 1 liter of oil into the fill plug until its spilled out instead of 0.7 liters as recommended by Honda !!

So after i took the car to the work shop today,my mechanic was just clean all the oil leak and i saw the leak seems like comes from the fill plug, so he unbolt the fill plug and there were a lot of oil left in the diff as its spilling out when he unbolt the fill plug,then he put everything bolt on back to normal and said its just like because of an overfilled oil into the diff from last serviced !

After that i just drive the car to work and come back home about 300 km and as i can see so far there are no further leak to the diff for now !

So just need some genuine advices about this happened . Is that normal and just becaused of an overfilled or there is something else i need to check out to my diff ?

Helps will appreciated !

Even if the diff is overfilled I wouldn't think it would leak from the fill plug. Fill plug should be tight and use an aluminium washer.

There is a vent on top of the diff but it would have to be pretty full to leak out of there.

But if the level is now good and the fill plug properly tightened you should not have issues.

Fill plug won't leak if it's overfilled.

So its mean there are leak from somewhere else ??
But how come i saw its leak from the fill plug when we checked up ???
And its not leaking now !!!

Hmm, just thought of how you could get a leak at the fill plug. 8(

If you over tighten and crack the diff cover...

Are they any chances of the heat ?
Because it was around 35-39 degree on the last few days,do you think the oil gna expand in hot weather ?

not that much.

Diffs get much hotter from friction than ambient.

Hmmm but haven't see any further oil drop on the ground atm !! Should i check it again this week or not ?

Keep checking, could have made it too tight and cracked the cover slightly. Should be ok though.

What about if the cover cracked ? Can i just do anything about it ??

if it's not leaking anymore don't worry about it.

monitor the situation and if there is further leaking investigate further.

Start with bolts, then move to other areas. Cracked diff case is unlikely but possible...

^ what he said.

Worse case is the case is cracked. Involves pulling the pumpkin, removing cover and having it welded (or replaced).

Best case is it doesn't leak again. Just keep an eye on it.

dont stress too much mate.

Rear diff filler hole could leak for a few reasons.

when you mechanic changed the oil, did he put a new aluminium washer and wipe the surface. if he reused the washer he is tight and i wouldnt go back. re-using the washer can work no worries but sometimes the are too crushed and they no longer seal. Make sure washer is new.

Unlikely that you cracked the diff case but its a possibility. when you havee aluminium washers, you do not need to over tighten them at all. they seal easy. factory torque spec would be in your owners manual.

just look under the car before you get in it in the mornings and see if its still leaking. if not dont worry.
if yes investigate further and replace washer again... do not over tighten.

some mechanics use the same washers and they can leak

Yea thanks guys
I still keep an eye on it till now . Did a service again few days ago with a new washer so they are seem like no further leak to the diff !

If you goto greenacre most of the mechanics there would do it cheap and quick, it doesn't really take much skill to weld a crack shut. Actually if u could get ap hoto of the crack we could probably tell u if its worth getting repaired or replacing - sometimes u can come across good diffs for dirt cheap specially in your area. Fairfield had a fair share of gd wreckers back in the days.