problems with 2002 toyota 78 series transmission 92000 kilometers

Robert, not at all familiar with Toyota's, but http://www.lcool.org/forum/ should be able to help you out, good luck.

The issues with the R151F box get discussed a lot on the "Troopcarriers of Australia" Facebook Group and there are a couple of experienced Landcruiser mechanics on that group.

Robert,
Usually a transmission fault will make it's noise everytime you begin.
I would be first looking at the front spring hanger bushes and pins for looseness which jumps the whole spring forward slightly until it hits and stops, therefore taking up slack as torque is delivered to the driveline. Because some movement can happen in suspension the driveline WILL flick and appear as though it is loose. Sometimes on cruisers the spring wrap is close to the front hanger anyway and ANY bush degredation makes the spring wrap "kiss" the hanger and the it feels in the driveline.
Not always a driveline problem.
If it is a drive on the LHS of the road, most likely the LHS front bush/pin/spring. If drive on RHS of road then possibly the RHS is the culprit.

Hi Rob. Have you checked the tailshaft universal joints, they make a "click" or "clunk" type of noise when they get worn. Just climb under and see if there is any play in them.
Good Luck
Len

thank you all for help........ we have found from underneath that the noise is coming from the trans on forward movement 70% of the time. a person was under when the vehicle was moved forward and he could hear the area of the noise. is this the beginning signs of the faulty 2 piece shaft on the 2002 troopy? has anyone had this problem before replacing the shaft with the newer 1 piece shaft?

There was/is a problem with this transmission where, due to wear & tear, and maybe lack of maintenance, the gear set in the t'case would wear the main shaft spline and, in extreme cases, the gear set would spin on the main shaft. Don't recall if the symptom you mention was noticeable prior to a loss of mobility?

On pass. side of t'case, there is a plate maybe 70 x 150mm in size. Remove this and the rear of mainshaft should be visible. There will be a double gear set held by a large flanged nut. If this nut is at all loose, then there will be accelerated wear on the splines. To tighten the nut, remove the cone shaped tin cover at the rear of t'case.

If the double gear set has play on the spline, then a quick fix is to weld(using suitable low hydrogen rods) the 2 sections together, using the side opening for access. A longer fix would be to remove rear of t'case & weld 2 sections of gear set together.

As suggested by others there may other areas causing the slop in the drive train. Uni's, rear pinion gear, wear in rear diff, spline on rear tail shaft.

Good luck,
Bob

thanks bob great info.... the noise is for sure coming from the gearbox and not other areas of the vehicle. we had someone stand below in a pit while we moved the vehicle forward and he verified the noise in the gearbox. my question is can this shaft be replaced by separating and dropping the transfer case without dropping the transmission? also i hope i have the correct one piece shaft to install. does anyone have the part number of the shaft needed and what other parts seals and gaskets that we will need to replace. thanks again for all the help.