1PZ to 1HDT conversion - 70 series (1 Viewer)

[willnz]

Hi guys, I am rebuilding a 1hd-t with the intention of replacing the 1pz in my pzj73 landcruiser. I have read about people swapping the 1hz with the 1hdt and it seems like it should be almost the same, but I still have a few questions.

Gearbox - I originally thought I would keep the original r151 box and source a 1hz flywheel (1hdt came from auto) and use a heavy duty clutch. Apparently the bellhousing for a 1pz is slightly different to 1hz/1hdt so that would have to change too. However I have come across a h151 for sale with flywheel, it seems like that would be an easier and more sensible option (but more expensive). The problem is that the h151 has a full time transfer case.. Could I swap the transfer case from my 1pz?

Also, would I have to change anything with gearbox mounts, driveshafts or selector levers?

I have seen an h55 for sale also, but it was from a 3b so i would have to get new input shaft and bellhousing. And it is shorter so the selector lever would be relocated if I am correct? I would rather not have to cut holes or weld things to get it in..

The gearbox is my main concern but I also wondered about the following:

- fuel lines for 1pz to small?
- radiator to small?

Any other tips would be great!

Cheers, Will

 

[crushers]

same rad PZ and HZ
fuel lines same size
the PZ tranny will bolt behind the HDT, use the HZ flywheel combo you MIGHT have to drill and tap the upper 2 mounting holes on the block. i would run a H55.
you will need to move the tranny back to allow proper clearence in the engine bay.

 

[Tapage]

. i would run a H55.

better tranny than H151 and R151 well better than probably all other Toy trannys ..

 

[Dougal]

The 1HD-T is more efficient, so it'll produce a lot more power and torque from not much more fuel or radiator heat.
Your fuel lines and radiator should be fine.

 

[willnz]

Thanks for the responses.

I still get the impression that the h55 would be more difficult to get set up..?

If I went with an h151 does anyone know if I can use the transfer case from my 1pz? And if the gearbox mounts will be the same?

 

[willnz]

Thanks for the responses.

I still get the impression that the h55 would be more difficult to get set up..?

If I went with an h151 does anyone know if I can use the transfer case from my 1pz? And if the gearbox mounts will be the same?

Sorry i mean using the transfer case from my r151 box on the h151

 

[wongtsenhin]

Sorry i mean using the transfer case from my r151 box on the h151

Doesn't fit at all.

 

[Petzel]

I swapped out my PZ for a 1HD-T and went with the H55F(with input shaft changed). Your T-case will bolt up to the H55F. You just need to get a bell housing, flywheel and heavy duty clutch for a HZ. While you are at it, you may as well rebuild the t-case. Rad and shroud will work with the 1HD-T.

Notes from memory:
transmission cross member from H55F on 70 series
vacuum canister will be in the way of turbo
airbox lid and piping to turbo
H55F transmission cover out of BJ70

Hope that helps. It is so nice driving the 1HD-T compared to the PZ with the dual mass flywheel that WILL break on you!!! More power now and nicer shifting.