80 series 1HDT to 1HDFT. What do I need

[Diorama]

After destroying my engine last weekend I've decided to replace the 1HDT in my 80series with the more modern 1HDFT 24valve engine.
What I would like to know is besides the engine what am I going to need. Looking at getting the engine from a 96 or later 80 series. Do they have a different trans. My trans is fully hydraulic so I know I can bolt straight to it and it will work. Did the later 80 series with the 1HDFT engine have a different trans. If so am I better to change as my trans was always a weak point as I do a lot of heavy towing. If I change trans what else am I going to need i.e. is it computer controlled. will I have to do anything with the speedo.
Basically I need to know everything I would need to do the conversion.

I managed to pick up a second hand 1HDT to keep me going till I sorce everthing I need.

[BlakeNZ]

you keep saying the trans was a weak point. Can you explain what you mean please?

[Diorama]

you keep saying the trans was a weak point. Can you explain what you mean please?

I tow a 3.5T boat. I have installed 3 auberins gauges Boost, EGT and Trans temp. On hill climbs with the boat on the trans gets pretty hot. I have an alarm on it so when it goes off I pull over and select low range. I have done the mod so I it doesn't engage the centre diff lock. Means I can stay in 4th gear with the torque convertor locked so the trans cools off. I have also put a new valve body in which enables the trans to lock in 3rd gear provided I'm above about 55k. As soon as it unlocks the temp climbs rapidly. Either a better trans may be the answer or more power to keep my speed up hence a locked convertor. Since I need to do something as far as engine goes may as well upgrade.

[Im a Tumor]

Have u tried putting a larger transcooler on?

[Diorama]

Have u tried putting a larger transcooler on?

Yep
trouble is once my speed drops there's very little air flow through it compared to the heat being generated. Even put an aux fan in front that I can turn on.
Its all about keeping the torque convertor locked for as long as possible

[sig]

trans difference i think is 1hdt is full hydraulic and 1hdft is computer activated solenoid controlled ( correct me if i,m wrong)

[silveradoman]

go manual ?

[Big]

trans difference i think is 1hdt is full hydraulic and 1hdft is computer activated solenoid controlled ( correct me if i,m wrong)

nup.. mine is electronic controlled trans 92 1HDT i think the 91 is hydraulic.. very interested also in this or even change from 12v to 24v head and pistons as an option...

[Lchundy]

you keep saying the trans was a weak point. Can you explain what you mean please?

I tow a 3.5T boat. I have installed 3 auberins gauges Boost, EGT and Trans temp. On hill climbs with the boat on the trans gets pretty hot. I have an alarm on it so when it goes off I pull over and select low range. I have done the mod so I it doesn't engage the centre diff lock. Means I can stay in 4th gear with the torque convertor locked so the trans cools off. I have also put a new valve body in which enables the trans to lock in 3rd gear provided I'm above about 55k. As soon as it unlocks the temp climbs rapidly. Either a better trans may be the answer or more power to keep my speed up hence a locked convertor. Since I need to do something as far as engine goes may as well upgrade.

Your at the limit of what a cruiser rated to tow
You running bigger tyres etc(extra stress on driveline)
Maybe re gear it or buy something big and American or get smaller boat?

[Diorama]

trans difference i think is 1hdt is full hydraulic and 1hdft is computer activated solenoid controlled ( correct me if i,m wrong)

nup.. mine is electronic controlled trans 92 1HDT i think the 91 is hydraulic.. very interested also in this or even change from 12v to 24v head and pistons as an option...

Mines Hydraulic control

[Diorama]

you keep saying the trans was a weak point. Can you explain what you mean please?

I tow a 3.5T boat. I have installed 3 auberins gauges Boost, EGT and Trans temp. On hill climbs with the boat on the trans gets pretty hot. I have an alarm on it so when it goes off I pull over and select low range. I have done the mod so I it doesn't engage the centre diff lock. Means I can stay in 4th gear with the torque convertor locked so the trans cools off. I have also put a new valve body in which enables the trans to lock in 3rd gear provided I'm above about 55k. As soon as it unlocks the temp climbs rapidly. Either a better trans may be the answer or more power to keep my speed up hence a locked convertor. Since I need to do something as far as engine goes may as well upgrade.

Your at the limit of what a cruiser rated to tow
You running bigger tyres etc(extra stress on driveline)
Maybe re gear it or buy something big and American or get smaller boat?

I have already done the diffs and changed the ratio. The gearing is now what it should be. Speedo reads accurate. Changing vehicles is not an option for me. Smaller boat no. I want to go bigger.

[Lchundy]

What's gears you get 4.88 or 5.29?
4.88 gets you closer to standard gearing with 37s
5.29 gears it down more than standard but improves pulling power with 37s
I have a 80 with 37s running 5.29s
Loaded up with 4 people ,camping gear,full exo,tool etc it still goes ok with standard engine running factory 8-9psi no intercooler or after market trans cooler.