Thread: Mystery noise (Loud bang)

The vac switch directs vacuum to either side of the diaphram. If the diff lock is engaged and there is a leak in the system, it wont disengage.
The first thing I would do is jack up a wheel and see if the diff lock is in fact engaged.

Cheers, Murray

Without some indication as to where in the drive train it's coming from it is just a guessing game. Some possibilities are uni joints, centre diff cross shaft gears (noticeable when turning corners), gear damage in transfer/gearbox or front/rear diff centre gears.

Could also be the hand brake not releasing till moving off , Does it happen after being parked for awhile with the hand brake on and just after taking off

Originally Posted by rijidij

The vac switch directs vacuum to either side of the diaphram. If the diff lock is engaged and there is a leak in the system, it wont disengage.
The first thing I would do is jack up a wheel and see if the diff lock is in fact engaged.

Cheers, Murray

I think this might be misleading, to my understanding the vaccume CDL has atmospheric pressure on both sides of the diaphram thus no actuation and CDL disengaged but when you use the knob in the cab to select engagement the vac pump buy its nature reduces the pressure on one side of the diaphram, this reducing pressure on one side allows atmopheric the greater pressure to push the diaphram and selector to engage the CDL. So if you have a vac leak you won't be able to select CDL thus it won't be the reason its stuck.

Could it be the noise of the Isuzu?????????

as bearman has said it is hard to tell with out more info. dose it still move, the high low selector could have jumped out of gear one of my box's has done this once and I thought the sky fell in. but it is really a process of elimination. keep posting info

A loud bang coming from under a Land Rover? Never!

My 120 did this for a while, it sounded as though something really big and important snapped, usually when taking off and with a load. I later found that the front radius arm bushes were completely stuffed and the bang was from one radius arm whacking the chassis mount as the front axle torqued on take off.

There was also the transfer case jumping out of which ever position it was in, but that is pretty obvious because you'll then proceed to come to a standstill, after the loud bang. un-nerving I klnow. I found the cause of this, in my case, to be that my once favoured mechanic, Silastic and Son, over did the goo when putting the output housing back onto the transfer case. There is a machined recess in the housing that needs to be clear for the high/low selector shaft to move into, but when full of silastic, it cannot. There is also a divot on the shaft for the spring loaded retainer to keep it in either high or low position. This also had silastic in it so I could not be sure the Rattler would stay in either high or low until I removed every last scerric of of the offending goo.

There are not many things on a Landy that wont go bang at some stage of the game, but only the really big BANGs should stop you...

Hi guys,
Did this one get resolved? i am thinking i have a similar issue with my RRC, had the CDL engaged driving up at stockton dunes on the weekend, when we pulled up i noticed a hissing noise (vacuum leak?) definately coming from the CDL push pull lever and after trying to cover it and some forwards and backwards the diff lock light remained on.. but went out a few k's down the road.. if it is a leak is it an easy fix?