transmission? H150 or H55

[beanz2]

Hey guys, I have an HJ75 troopie I am about to swap in a 1HD-T turbo diesel. The engine came from a GXL 80 series and came mated to an aluminium H151f transmission and a full time transfer. I have also bought a lower ratio H150f transmission and a part time transfer from a DX 80 series with the thought of swapping these instead of the full time transfer and higher ratio H151 tranny.

Now, the HJ75 has an H55f iron 5 speed. The fellow I've asked to swap the new drivetrain is having reservations about using the larger aluminium tranny as he says the floorboard needs to be cut, the support crossmember needs to be relocated because the aluminum tranny is much larger (though stronger), the propeller shafts would need to be resized, etc. etc.

I know Toyota never intended the iron tranny (H55) to be mated to the higher powered turbo diesel. And the higher powered petrol 1FZ-FE and the turbo diesels always are mated with the larger aluminum tranny. My preference is to keep the aluminium tranny but this guy does an excellent job swapping engines.

Should I insist on using the aluminium tranny or would the iron one be good enough? I would hate not using a transmission that was so difficult to obtain around here, but then, using the iron tranny would let me keep the modifications to the rest of the vehicle to a minimum.

Cheers,
Dave

[dumbdunce]

"quick60" on this board has a 1HD-T in a 60 series with the H55F gearbox, he has quite a few years and km on it and it seems to go pretty well. the H55F is not bulletproof by any means but it will stand up to some punishment. They seem to manage ok behind chev V8 diesels in 75 series etc.

that said, I doubt that it would be necessay to cut any of the body of a 75 to fit a H150F.


cheers

Brian

[beanz2]

I might just keep the H55f for a bit then if and when it croaks I'll swap the H150f in.

What the guy is saying is the floorboard needs some cutting to allow for the H150f/transfer shifters. Are the floorboards on the FJ75/HJ75 and the HZJ75/FZJ75 different? I know the FZJ75 has had the H151 since 1993.

I got some suggestions from guys on this and another forum to use an Isuzu clutch disc as it has the correct splines to work with the H55f input and the correct 300 mm diameter. The one that seems to fit is one specified for an NPR Isuzu delivery truck with a 4BDT engine. These cost upwards of US$325 (AU$465) around here. How much do these cost in Oz?

Dave

[dumbdunce]

I might just keep the H55f for a bit then if and when it croaks I'll swap the H150f in.

What the guy is saying is the floorboard needs some cutting to allow for the H150f/transfer shifters. Are the floorboards on the FJ75/HJ75 and the HZJ75/FZJ75 different? I know the FZJ75 has had the H151 since 1993.

I got some suggestions from guys on this and another forum to use an Isuzu clutch disc as it has the correct splines to work with the H55f input and the correct 300 mm diameter. The one that seems to fit is one specified for an NPR Isuzu delivery truck with a 4BDT engine. These cost upwards of US$325 (AU$465) around here. How much do these cost in Oz?

Dave

no idea on the clutch - surely you could have a custom clutch disc made up for not heaps if you supply the coarse centre off a H55F clutch and the disk from the H150F? or use a 1HZ flywheel and a daikin safari tuff clutch, has plenty of bite for the torque of the 1HD-T.

as for the floor, it would probably only require cutting to the section that unbolts anyway? not a big deal, probably worthwhile bending up and cutting a custom plate to suit the shifters, or maybe getting your hands on the floor section from a '93+ model.