Toyota Repair: Toyota Hilux 3.0 KZTE 4x4, toyota hilux, clutch pedal

Question
My name is Reinier. I live in South Africa.
I drive a Toyota Hilux(Tukamo..I think) 3.0 KZTE Diesel 4x4 with manual transmission.
When de-accelerating against engine compression in 3de, 2de or 1ste gear (4th does not have enough compression from the engine) there is a ticking noise comming from the gearbox, or so we though. We have had the gearbox ckecked and nothing wrong was found. When engaging the clutch while the noise is there, the noise dissappears. When accelarating there is no noise. When the engine speed drops below 2000 rpm, the noise dissapears.

Please Help

Thanks

Reinier

Answer
The problem is inside the transmission, the reason I'm sure this is the case is the fact that the noise goes away when the clutch pedal is pushed down, this completely disengages the transmission from the engine and all gears inside the transmission stop turning.
When you release the clutch in neutral all the gears are turning but none are selected and the car does not move until a gear is selected, so it is possible to hear the noise in neutral as well.
The reason you don't hear the noise in fourth gear is that the transmission mainshaft is locked straight to the driveshaft and no gear reduction is used, the transmission countershaft gear is spinning without any load on it, I suggest that the transmission is disassembled and checked very closely for any chipped gears or bad countershaft bearings. Unless you know how a transmission works what I said probably won't make much sense to you but in any case that is where the problem is.