Land Rover Disco 1 - ZF4HP22 auto box clunk. When I am cruising along in top gear, slowing down using the brakes, there is a loud embarrassing clunk from the drive train as it drops down to 3rd gear.
I don't get the clunk in any other situation. If the rate of deceleration is slow, by cruising slowly up to a set of lights, the noise is much softer and not noticeable, but if I apply the brakes to slow down in a normal manner, that's when the loud clunk occurs. I changed the auto oil and filter only about 5000km ago. The gear changes are a little sharp also, as I accelerate hard.
There does not seem to be any radical backlash wear in drive shafts, wheel drive nuts, diffs, etc that I know of.
I note that if I select 3rd gear for driving around town, I never get the problem. Its only when I am in Drive and slowing down. Is this a common problem?
I am assuming it’s a gearbox problem? would a gearbox service likely help?