LT230 clack noise and lever twang!

[Eightpot]

I'm working on a Defender with a freshly rebuilt Ashcroft transfer box, and struggling with an annoying loud clack from the box on pulling away and coming to a stop - it also gives a little kick backwards on the hi/lo lever but doesn't make the sound/kick if you hold the lever back.

Have made sure difflock/hi-low engage fully, everything else in the transmission is new though the noise is definitely coming from the lt230.

not come across this before - any ideas before I pull the box and swap it??

[Snagger]

Could it be a matter of adjustment of the selector fork causing the synchro unit dog teeth to be fractionally out of their ideal running position when the detent ball engages in the selector shaft groove, so the lever is where the detent wants it but the teeth then pull everything into the position they want when torque is applied?

[Eightpot]

That's roughly my first thought, the noise does seem to be coming from that area. Annoying as it only seems to be a fractional thing but the sound is probably amplified being in the dry part of the casing.  It will repeat the trick everytime you reapply the power as well.

Just trying to run through anything daft I might be missing before resigning to pulling it back out 😕

[bishbosh]

Is the handbrake correctly adjusted? Mine was just binding a tiny bit and when coasting to a stop made one hell of a racket that I thought initially was driveline or t case related. After swapping out the tcase and fitting new drive flanges I still had the noise. I eventually stumbled across a post on here from years ago that pointed at the hand brake. 30 seconds with a 17mm socket and all was well.