100 series VX 4.2litre Turbodiesel 1998 model automatic gearbox problem

[Crag Rat]

Hi Guys. My car started overheating when accelerating on uphill climb and also when negotiating very sandy tracks on level ground. The latter was at around 15 to 20 km/hr in 2nd gear. The radiator was boiling and the A/T oil temperature warning light showed up. The gearbox oil smells burnt. I've been told it's burnt clutches. The car still runs well on tarmac and gravel roads at up to 100 km/hr with revs around 2800 rpm keeping fairly steady. No overheating. My question is this...does anyone guess how long the clutch will last under such circumstances without completely failing? The odometer is around 300k. Many thanks

 

[Jon Wildsmith]

If the gearbox oil smells burnt, it needs changing.

If the radiator was boiling, then you have an engine cooling problem, which may be the reason your gearbox overheated.

 

[Crag Rat]

Thanks, Jon. The engine cooling system has been checked and it's fine- I have driven over a 1000 kms on tarmac and gravel roads at 100 kph and engine does not overheat- however, on very steep roads and sandy roads, when the gearbox has to work hard, it over-heats.

 

[forkliftdrew99TD42&LC300]

CragRat, I have a very similar issue with my TD42T patrol (factory setup). Overheating can be caused by many things, it’s not just your gearbox working hard up hills and on dunes, it’s your turbo is on full boost and when that’s happening, your fuel pump is spewing extra diesel into the engine to create more power. More fuel = more heat. I just replaced my factory radiator after 22 years service. I sent it to get ‘rodded’ and the shop said “it’s 50% blocked and will fall apart. New one required”. So I replaced it, also the thermo fan clutch, all hoses, all belts, thermostat and even the fan itself (the blades were cracking and likely to let loose). So ever since then, i cannot get the temp gauge to move, even on sand/towing up Cunningham’s gap (both situations i used to overheat on. So given your vehicle vintage, I’d suggest a cooling system overhaul and flush out. I ran mine on straight water for a few short trips and kept draining it. Surprising how much keeps coming out. 24years of service will do that. The other thing to consider is worn injectors/injector pumps, as they deteriorate and can alter fuel timing, which means the injectors crack later and the extra fuel isn’t given the time/air it needs to burn. That results in extra engine heat (and dangerous EGT’s), so a tune might also help. Also don’t look past any missing wheel arch rubbers and cowlings around the engine bay. Missing flaps impacts the intended factory flows. So it may not be a gearbox issue at all, it’s just your gearbox can’t get cool because your radiator isn’t working for it.