GTSSportCoupe
2LTE abuser
Thought I'd post up some info for all you LJ7x owners out there. In all my experimenting with the 2LTE and LJ78, one of the best upgrades is dumping the pathetic undersized radiator fan for a proper size fan. It makes an immense improvement in cooling. All the 'heavy duty' landcruisers come with decent sized fans. Toyota put a small fan on the Prado, even though the truck weighs just as much as the other cruisers, and the engine works just as hard if not harder. After the first generation cylinder head cracking problem, I'd say this is the #2 design flaw on these trucks. Toyota probably did this to reduce the noise and parasitic draw on the engine. FAIL.
I've tried a few fans and hubs now. The problem with many of the North American gas engine fans is they have the wrong offset. So I had made a spacer on the waterpump to deal with this. This was a PITA and beyond most DIY mechanic's ability to do as it require a lathe to make it. So I found a fan that is an ideal bolt on upgrade. I'm very happy with it, and it is a relatively easy and economical upgrade for everyone out there.
If you guys do this upgrade, please also service the viscous hub at the same time! It makes all the difference. Follow the instructions by the OP in this thread: Blue fan clutch mod
The fan I upgraded to is Toyota part # 16361-17010. It's found on a ton of cruisers out there including all the HZJ7x, PZJ7x, HDJ8x trucks of the early 90s. It's what should have been put in our trucks to begin with. This upgraded fan has the right offset, has eight 'swept' design blades. It's 17.5" in diameter instead of 16.5" (stock Prado fan).
Now, the only thing I can't comment on, is how well this fan fits the upper part of the factory LJ78 fan shroud. Reason being, I had cut that out and riveted a piece of metal there a long time ago during my past fan upgrades. So it is possible this fan will interfere with the upper part of the factory shroud. You can see in my pictures how I modified mine however. Just do the same thing if it's a problem. It might seem the fan clears the upper part of the shroud, but be aware, that when the fan is running hard, the blades pull in toward the radiator a fair amount, and might interfere at that point.
Also, I've run a few 17.5" fans before. I've done a lot of off road driving. The bigger fans have never hit the shroud while the truck is flexing. The frame is very strong on the 70 series and does not seem to flex as much as the older 40 and 60 series frames (I often hear the fans hit on those trucks while we're out wheeling).
I'm using this fan on the LJ78 viscous hub. However, I did get a HDJ81 viscous hub with the fan as well. I may give it a try in the future. I compared the HDJ81 hub to a untouched LJ78 hub, and the HDJ81 hub is a few mm longer (would bring fan closer to rad). The HDJ81 hub is much stiffer though. I'm thinking it might be a superior design inside, or maybe Toyota put better silicone fluid in it. Or perhaps the silicone fluid inside is just newer.
I've tried a few fans and hubs now. The problem with many of the North American gas engine fans is they have the wrong offset. So I had made a spacer on the waterpump to deal with this. This was a PITA and beyond most DIY mechanic's ability to do as it require a lathe to make it. So I found a fan that is an ideal bolt on upgrade. I'm very happy with it, and it is a relatively easy and economical upgrade for everyone out there.
If you guys do this upgrade, please also service the viscous hub at the same time! It makes all the difference. Follow the instructions by the OP in this thread: Blue fan clutch mod
The fan I upgraded to is Toyota part # 16361-17010. It's found on a ton of cruisers out there including all the HZJ7x, PZJ7x, HDJ8x trucks of the early 90s. It's what should have been put in our trucks to begin with. This upgraded fan has the right offset, has eight 'swept' design blades. It's 17.5" in diameter instead of 16.5" (stock Prado fan).
Now, the only thing I can't comment on, is how well this fan fits the upper part of the factory LJ78 fan shroud. Reason being, I had cut that out and riveted a piece of metal there a long time ago during my past fan upgrades. So it is possible this fan will interfere with the upper part of the factory shroud. You can see in my pictures how I modified mine however. Just do the same thing if it's a problem. It might seem the fan clears the upper part of the shroud, but be aware, that when the fan is running hard, the blades pull in toward the radiator a fair amount, and might interfere at that point.
Also, I've run a few 17.5" fans before. I've done a lot of off road driving. The bigger fans have never hit the shroud while the truck is flexing. The frame is very strong on the 70 series and does not seem to flex as much as the older 40 and 60 series frames (I often hear the fans hit on those trucks while we're out wheeling).
I'm using this fan on the LJ78 viscous hub. However, I did get a HDJ81 viscous hub with the fan as well. I may give it a try in the future. I compared the HDJ81 hub to a untouched LJ78 hub, and the HDJ81 hub is a few mm longer (would bring fan closer to rad). The HDJ81 hub is much stiffer though. I'm thinking it might be a superior design inside, or maybe Toyota put better silicone fluid in it. Or perhaps the silicone fluid inside is just newer.
Is that a factory LJ78 fan you have there ? Could you compare for me the dimensions in the photos I posted on Nas90tdi build thread ? Maybe this way we could have another option for a different part numbered fan.
The blades definitely pull in toward the radiator when the fan is getting full power, so you need at least a 3/4" clearance there.
