Outer Limits 4x4 Board

All the crown wheel bolts came loose and fell out and mashed up in my back diff ( GU diff centre/ARB locker ) made quite a mess. I fitted the locker and and used loctite 262 and Primer "T" on the bolt threads and they came loose. If it wasn't for a job i done last week on the front diff of a fulltime 80 series that all the crown wheel bolts came out and destroyed the diff and locker ( dont know who fitted the locker ) are the only ones ive heard of this happening. Ive been fitting Air Lockers for over 15 years and never had it happen before. A bit disturbing as it was fitted correctly and they came loose. Im drilling the heads of the bolts this time and lock wiring as an extra precaution. I know 80 fronts and Hiluxs have locking tabs on the crown wheel bolts STD but are discarded when fitting a ARB locker and use Loctite to secure the bolts but on Nissan diffs they only use Thread Locking compound. Has any one had this happen also

Wally

I've seen it wally it happened to Henry (pro comp) some time ago. I clean the threads and bolts with brake clean and use red high strength loctite.
Cheers
Joel

happened to m,y daily driver also, except the locker had been in for some where around 15 years or so before they came loose

when one of my bolts came out, it took a chunk of the crown wheel mounting surface of the locker with it, but i used metho to wash out the bolt holes and loctited it all back up, hasnt had a dram since,
]

had it happen on my daily driver (welded center)

5 of the bolts sheared off, and one spat out the coverplate on the diff

left a nice 1.8km oil trail through a nice snooty estate

This happens a bit with aftermarket patrol crown wheels, some of the crownwheel threads aren't an exact match.

Liam wrote:This happens a bit with aftermarket patrol crown wheels, some of the crownwheel threads aren't an exact match.

They are/where genuine gears and bolts.

Wally.

I`ve had the locker housing bolts come loose and go threw the gears but not the crown wheel bolts.

there are a few things that might cause this. Overtorqueing the crownwheel bolts causes distortion of the crownwheel itself and the thin flanges, which can cause minute oscillations as the diff rotates under load. Pulling the crownwheel on with the bolts instead of heating it and dropping it over the centre will definitely cause it. excessive or insufficient carrier bearing preload will also cause it. This can be an install time problem, or an issue of big tyres, generous power or a combionation of. It's not a common problem but it does happen. Drilling the bolt heads and adding lock wires will only prolong the inevitable if it's going to happen.

Daniel Bongard of ARB might have more tips for avoiding this failure.


cheers
DD

Well, Wally doesn't have generous power or big tyres so it can't have been that

Sorry for not adding any tech... couldn't resist.

Have seen the bolts come loose that clamp the centre together on the 4 gear sierra diffs when welded, but not crownwheel bolts.

Steve.

put a full spool in this is another good alternative