Toyota 80 Series LandCruiser 1HD-FT with a 5 Speed A750 Tip-Tronic Automatic

About the Author

Jonathon "Jono" joined Wholesale Automatics in 2013 to provide a solid IT / Computers / Electronics background. Jono has been instrumental in the development of the Land Cruiser 6 Speed Automatic, Land Cruiser 5 Speed Automatic and Nissan Patrol 5 Speed Automatic Transmission Computers. Jono also leads the development of the Torque Converter Lockup kits and the Website.

In 2008, I made the decision to purchase my first 4WD. It came down to two choices – 80 Series Turbo Diesel or Nissan Patrol GU 4.2 Turbo Diesel. The 80 Series Won and in rolled my stock standard 1996 4.2 Turbo Diesel Multi-Valve 80 Series. Proud as punch I was.

Of course the first thing anyone does when they buy a 4WD is deck it out with everything they can; bull-bars, winches, mud tyres, dual battery system. I was no different.

But one thing I was in 2 minds about was the fact it was a Manual. I liked the idea of a Manual that gives you full control over what is happening, you select the gear because you know what you will need for the current scenario.

However, I have a little teeny incy wincy problem with my left foot… I don’t have one!

So I spent most of the time crunching 2nd and 3rd gear because my prosthesis can’t bend at the ankle and I have trouble pushing the clutch all the way to the floor. I was determined to master it, but unfortunately I could never get a consistently smooth gear change.

Fast forward 5 years and I’m now working for Wholesale Automatics, specifically handling the Manual to Automatic Transmission Conversion Projects and the Compushift Transmission Computer systems that we use to do the conversions. I had an idea, and that idea has finally come to fruition. Put the 5 Speed auto from the 100 Series into my 80 Series LandCruiser. But not just that, make it Tip-Tronic also. So out came the old H151 5 Speed Manual to make way for my beautiful 5 Speed A750 Automatic (and I mean beautiful in the way your child is always more beautiful than all others).

The H151 manual gearbox is 75mm shorter than the A750 transmission which meant some adjustments were needed to cross-member, drive-shafts and transfer linkages. The drive-shafts needed to be lengthened and shortened so I sent them out to a specialist and had them re-built at the same time. The transfer linkage simply needed a length of threaded rod welded in to lengthen it.

But much debate was done over how to do the cross-member. Originally we were going to cut and weld the cross-member but this obviously meant difficulty for being able to send these out as kits. The final decision was to plate it. This solved 3 problems.

The Cross-member needed to move 75mm rearwards
The Cross member needed to drop 20mm to allow for a slightly taller transmission
I REALLY didn’t want to hack my cross-member apart

After a couple of weeks of CAD drawing and laser cutting all the adapters and spacers to get them spot on, we finally had it finished…. well mechanically anyway. During that time, I’ve raided my shed for whatever timber I can find to make a temporary (wood-grained) console for the shifter assembly to sit in. Personally I think I did a great job. Would any one buy it? Don’t think so!

So this weekend, I’m on a road trip to get the mob that did an awesome job of our 70 Series 6 speed console, to make a console that looks the part (and it also needs to fit in the custom center console fridge that I am making – more on that another time).

We originally had some issues with signal compatibility with the LandCruiser 4.2 tacho but with some electrical wizardry we were able to get the RPM signal we needed. I have so far spent probably 150+ hours on test driving and calibrations to make sure we have ironed out all the bugs and get all the shifts running perfectly and I am extremely happy with were it is. All that is left is to tidy up is the 4-5 and 5-4 shifts, and now that we have tacho signal, to fix up the garage shifts (Park to Reverse to Neutral to Drive and back again)

The last software feature that we are working on for the A750 will be to do with the Torque Converter Lockup process. Through the use of the powerful processor inside the Compushift we will be implementing a software algorithm that will calculate, on the fly, a smoother application of the torque converter clutch. So instead of having a fixed speed and pressure application of the clutch, it will instead be applied using a algorithm that will apply the clutch smoothly in a given space of time. This will make application of the torque converter at low throttle far smoother.

The best part is that once we have it perfect will be able to roll this out to our other transmission controllers including the Toyota AB60 6 Speed and the Nissan RE5 5 Speed

Between the Brisbane 4×4 Show and some annual leave that I am taking it was a good opportunity to get the console work done. After the Brisbane 4×4 Show (11th, 12th and 13th March) our USA Software Engineer will be returning to help us go full steam ahead to finish off the A750 (and Nissan RE5) control systems.

Just a quick note on the different shifters usuable with the A750 Compushift Controller. The Compushift will be made with 2 different looms. One for the Tip-Tronic Shifter and one for the Gated Shifter. This means those with 100 Series 1HD-FTE and 2UZ-FE engines as well as Hilux 1GR-FE V6 Petrols can replace your factory ECU with our Compushift System while maintaining your factory Shifter. This will allow for infinite adjust-ability for those transmissions while still looking like it’s a factory vehicle.

Below is examples of the two types of shifters. Tip-Tronic or Sports Shifters has physical locations for Park, Reverse, Neutral & Drive and then usually a side shift to an area that allows for control over the gear changes by pushing up or down. Gate Shifters have a physical location for all gears and usually configured into a Z-Gate type pattern to prevent incorrect selection of a gear.

Tip-Tronic or Sports Shifter

Gate Shifter

The Differences

Factory Toyota 80 Series 5 Speed H151F Manual Gearbox Ratios

1st Gear	2nd Gear	3rd Gear	4th Gear	5th Gear
4.081:1	2.294:1	1.490:1	1.000:1	0.881:1

Toyota 4 Speed A442F Automatic Gear Ratios

1st Gear	2nd Gear	3rd Gear	4th Gear
2.950:1	1.530:1	1.000:1	0.765:1

Toyota 5 Speed A750F Automatic Gear Ratios

1st Gear	2nd Gear	3rd Gear	4th Gear	5th Gear
3.520:1	2.042:1	1.400:1	1.000:1	0.716:1

The above shows the differences between the Toyota 80 Series H151F manual, the standard 80 Series and 100 Series A442F 4 Speed Automatic and the 100 Series 5 Speed A750F Automatic. As you can see first gear in the A750 is not quite as low as the manual but equally lower than the standard A442F making it very good for take off and steep downhills. However the greatest benefit is out on the freeways when you get up to 100km/h and in 5th gear the engine revs drop to just under 1900RPM compared to just over 2000RPM with the A442F and 2300RPM with the H151 manual gearbox.

I am enjoying driving my 80 Series with the 5 speed auto soo much that I have a smile bigger that Joker and will continue to enjoy it for many decades to come. By the way, the sports/tip-tronic mode is awesome for having a bit of fun.

Cheers

Jono

Update

Just a quick update for those of you who managed to make it to the end of the post!!
Here is my finished console with the fridge section as part of it. Pretty happy with that result!