Life of drive train in turbodiesel auto after head replacement?

[Dukalook Lurker Find all posts View Profile Close Dukalook]

About 3 months ago the radiator on my 2001 TX (auto turbodiesel) failed suddenly at the housing for one of the ATF cooling lines, resulting in a near total loss of coolant and partial loss of ATF. At first I thought I had got away with just replacing the radiator, but soon afterwards I noticed an excessive amount of coolant was being transferred into the overflow tank and not syphoned back on cooling. A TK test confirmed that combustion gases were entering the radiator. Apparently the pre-combustion chambers in the 1KZ-TE motor are prone to cracking. So now I have a new aftermarket head and a new radiator, water pump and thermostat. I've been told that a head replacement often accelerates deterioration of the drive train and can lead to other expensive engine problems. I'm reluctant to quit the vehicle because it only has 160,000km on the clock, had been exceptionally reliable until the radiator failure incident and has around $12,000 worth of aftermarket upgrades and accessories that I would get next to nothing for. I should mention that I use the Prado to tow a 2.1 tonne off-road caravan into the back of beyond, so mechanical reliability is a big issue. Can't afford a new Prado and used ones with the D4D motor are still very pricey. Any advice?
GrahamS

[eatlovelearn Junior Member Find all posts View Profile Close eatlovelearn]

down grade the van if you can , i wouldnt tow anything over 1.5 tonne with mine , just to much strain

[williade Avid PP Poster! Find all posts View Profile Close williade]

Hi Graham,
Unless the transmission was damaged due to loss of ATF or from engine coolant mixing with the ATF, I can't see how any part of the drive train (transmission, transfer-case, prop shafts, diffs) would be affected by replacing the cylinder head.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

The Auto trans in the prado is one of the strongest in the business, it comes straight out of the Landcruiser 80 and 100 series. Like what Declan has said, unless the loos of ATF has cause damage to the trans, then you should be ok, however if you lost too much ATF, then the trans would not select any gears, preventing any damage. So at worst, you may have cooked the fluid, but a simple flush will fix that.

[Dukalook Lurker Find all posts View Profile Close Dukalook]

There's sometrhing to be said for that, Marty. Long towing runs with 2.1t behind is a bit of a strain for the old 90 Series. However, the van is worth a lot more than the vehicle and we enjoy using it, so if push comes to shove I'd replace the Prado with a younger second hand unit rather than replace the van.

[Dukalook Lurker Find all posts View Profile Close Dukalook]

Thanks Declan,
The scenario presented to me was that the additional power (doubtful?) resulting from the installation of the new head was likely to magnify any pre-existing weakness or deterioration in the drive train. I haven't felt any sign of transmission damage, although at the time of the radiatior failure, the vehicle felt as if I had put it into low range just as I pulled over (which was as soon as I noticed the engine malfunction warning light). That might be the effect that crooza talked about.
GrahamS

[Dukalook Lurker Find all posts View Profile Close Dukalook]

Thanks croozza. The ATF was flushed and replaced when the radiator was replaced. GrahamS

[Dukalook Lurker Find all posts View Profile Close Dukalook]

Hi Graham, sounds like everything is fine. You shouldn't have any problems with the driveline at those kms, as long as the driveline has been serviced properly. It would pay you to put on an aftermarket oil cooler for your auto transmission and take some of the heat out of both the cooling system and the auto especially seeing you are towing. It's a mod you should really do in the 90 auto models. One that mounts in front of radiator panel will do the trick and bring down those temperatures by about 30 degrees C.
Have a look at this link www.daviescraig.com.au under oil coolers.
Hope this helps, the Roo.

Thanks Roo: I will do this if I keep the old girl. GrahamS