78 Series rear Diff - but any other models had this issue?

TroopiePete

Member
Hi
I recently had my rear Diff explode while just driving around town, actually on the way to work!
Problem is I less than a month away from starting an 11,000km 7 week CSR trip so I am both pleased it happened now but pissed off it happened at all.
As I am not familiar with Diff's I thought it about time I became so, also the car was really not drivable although I got home in 4WD with the hubs locked as I had no drive from the rear Diff and at that stage had no idea what had failed.
To wind back a little back in May 2017 I had the diff rebuilt as it was making one hell of a whining noise.. again just before a Desert trip.
Move forward to the Madigan line trip last year and just as we started the line I noticed oil dripping from my Diff, on inspection i found all 10 Nuts very loose and it was almost out of oil, tightened all of the nuts up, it stopped leaking so we filled it back up with the correct oil (mate had a full bottle)
Anyway forgot all about this but have changed the oil since and no further leaks...
What has happened now and forgive me as I am still learning the terms but the two carrier bearings that hold the actual centre differential, in my case an ARB Air Locker the Left hand side it looks like one of the two bolts became loose then with mechanical stress it snapped the head of the other bolt.. this caused the centre to fall down, destroy the Locker activator and because the crown and pinion gears are not correctly meshed it has taken hunks out of both gears...
Needless to say I am not amused and will possibly never use that company again .. out of warranty and all..

SO the long and short - is this something others have experienced or am I the unlucky duck in the pond.
Taking it to a new guy recommended by a mate tomorrow.
 

Albynsw

Well-Known Member
I had a similar thing happen in my Hilux that had an Air Locker, one of the bolts rattled loose and went through the gears before getting spat out the side of the pumpkin cover.
 

Aaron Schubert

Moderator
Sounds unlucky mate, but if it ran for a while without oil you may have have damaged the bearings, which would have meant a rebuild anyway (although probably not to the extent it needed to be)

Aaron
 

TroopiePete

Member
Sounds unlucky mate, but if it ran for a while without oil you may have have damaged the bearings, which would have meant a rebuild anyway (although probably not to the extent it needed to be)

Aaron
The Diff only would have ran for a short time without oil - yes any time is bad but I doubt this caused any issues resulting in this fault.
Ray (Diff Guy) did find the input flange warped a little and this would have caused a vibration - even though never felt.
Still not clear on what caused the fault but it's now been basically completly replaced and rebuilt - only original part is the ARB Locker.
Worrying part is I depart for 7 weeks on the 1st of July and basically working full time so little time to play before then.
 

dno67

Well-Known Member
Sound like a possible conbination of sevral things going wrong lf the bolts were locktited and the head broke, possibly over tourqued. Oil leak, also suggests possible poor fitting, but the low oil was probably the fuse.
 

Buxter

Well-Known Member
Troopy Pete

You might find you don't need the diff lock in sand, but that will depend what you are used to
I don't find my ARB Diff lock and use in sand, it's all about tyre pressures

Cheers
Buxter
 

Buxter

Well-Known Member
Hi
I recently had my rear Diff explode while just driving around town, actually on the way to work!
Problem is I less than a month away from starting an 11,000km 7 week CSR trip so I am both pleased it happened now but pissed off it happened at all.
As I am not familiar with Diff's I thought it about time I became so, also the car was really not drivable although I got home in 4WD with the hubs locked as I had no drive from the rear Diff and at that stage had no idea what had failed.
To wind back a little back in May 2017 I had the diff rebuilt as it was making one hell of a whining noise.. again just before a Desert trip.
Move forward to the Madigan line trip last year and just as we started the line I noticed oil dripping from my Diff, on inspection i found all 10 Nuts very loose and it was almost out of oil, tightened all of the nuts up, it stopped leaking so we filled it back up with the correct oil (mate had a full bottle)
Anyway forgot all about this but have changed the oil since and no further leaks...
What has happened now and forgive me as I am still learning the terms but the two carrier bearings that hold the actual centre differential, in my case an ARB Air Locker the Left hand side it looks like one of the two bolts became loose then with mechanical stress it snapped the head of the other bolt.. this caused the centre to fall down, destroy the Locker activator and because the crown and pinion gears are not correctly meshed it has taken hunks out of both gears...
Needless to say I am not amused and will possibly never use that company again .. out of warranty and all..

SO the long and short - is this something others have experienced or am I the unlucky duck in the pond.
Taking it to a new guy recommended by a mate tomorrow.

Need to personally go back over each diff nut, (1 at a time) and wack some thread lock on them !
That will ease your mind
 
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