BJ and my best friend Bear (1 Viewer)

[Eurasiaoverland]

Mating a 1HD to an H55F will be an unusual conversion. Also getting the 6 cylinder in the engine bay will be a good bit of work, though it is definitely possible.

I've probably said it before, but why not just drop in a 14B or 15B, either a factory turbo (rare) or a turbo conversion? A factory 15B-FT has at least as much torque as a 1HD-T and can easily be made to beat the factory 1HD-T numbers, albeit without the refinement of an inline 6. But it will be a massive improvement on the 3B. They will bolt straight to your transmission with no further changes to transmission, transfer, cross member or engine mounts.

 

[fullthrottle]

Mating a 1HD to an H55F will be an unusual conversion. Also getting the 6 cylinder in the engine bay will be a good bit of work, though it is definitely possible.

I've probably said it before, but why not just drop in a 14B or 15B, either a factory turbo (rare) or a turbo conversion? A factory 15B-FT has at least as much torque as a 1HD-T and can easily be made to beat the factory 1HD-T numbers, albeit without the refinement of an inline 6. But it will be a massive improvement on the 3B. They will bolt straight to your transmission with no further changes to transmission, transfer, cross member or engine mounts.

Shouldn't be too hard. There have been a number of conversions similar to this, especially in OZ. So far I think it's just a 1HZ bellhousing, likely a replacement input shaft, new engine mounts welded to the chassis, will look at the thrust bearing and some other bits a pieces.
Won't know exactly until I pull it out and identify it a bit better.

Luckily there are a few clever buggers in the club who have mated all sorts of combos together. In some cases with a bit of machining. However if I can get a combo that works from standard parts, even better.

Why, the 1HDT was a really good deal and I've had those motors before and like them.

 

[Eurasiaoverland]

Shouldn't be too hard. There have been a number of conversions similar to this, especially in OZ. So far I think it's just a 1HZ bellhousing, likely a replacement input shaft, new engine mounts welded to the chassis, will look at the thrust bearing and some other bits a pieces.
Won't know exactly until I pull it out and identify it a bit better.

Luckily there are a few clever buggers in the club who have mated all sorts of combos together. In some cases with a bit of machining. However if I can get a combo that works from standard parts, even better.

Why, the 1HDT was a really good deal and I've had those motors before and like them.

Ah, my bad. Indeed the 1HZ bell housing will bolt straight on, that slipped my mind.

I'd be interested in the 3B input shaft from the gearbox in case you sell it, when the time comes.

 

[JuanJ]

Hello,

Is it possible to use an H150F transmission with the 1HD-T?

Just curious.





Juan

 

[fullthrottle]

Hello,

Is it possible to use an H150F transmission with the 1HD-T?

Just curious.





Juan

Yeah I believe so. I'm still careful in trusting the AI search, but according to that..........

AI Overview

+6

The H150F transmission, found in vehicles like the Toyota Land Cruiser with the 1HZ engine, can be used with the 1HDT engine, though it's often recommended to use the stronger H151F transmission, especially with higher power outputs. The H150F is a 5-speed manual transmission, and the 1HDT is a 12-valve 4.2L turbocharged diesel engine.

Compatibility and Considerations:

• Input Shaft Spline:
  The H150F typically has a 21-spline input shaft, which may require a different clutch disc if swapping from a 1HZ with a different spline count.
  
  
• Power Handling:
  While the H150F can handle the 1HDT's power, it may be better suited for lower power tunes. If planning significant power increases (e.g., over 200HP and 600NM torque), the H151F is often recommended for its increased strength.
  
  
• Transfer Case:
  The H150F's transfer case may need to be swapped or modified depending on the specific application and desired transfer case setup.
  
  
• Clutch:
  The H150F will require a clutch disc designed for the 1HDT engine and the 21-spline input shaft, according to a parts website.
  

Alternatives:

• H151F:
  The H151F transmission is often preferred for 1HDT conversions due to its stronger construction and suitability for higher power levels.
  
  
• H152F:
  The H152F, found in later VDJ7# models, has taller gear ratios, and the transfer case may need to be swapped when used with the 1HDT.
  

In summary, while the H150F can be used with a 1HDT, it's crucial to consider the power output, potential need for a stronger transmission (H151F), and appropriate clutch components for optimal performance and reliability.

 

[JuanJ]

Yeah I believe so. I'm still careful in trusting the AI search, but according to that..........

AI Overview
View attachment 3955606
View attachment 3955607
+6

The H150F transmission, found in vehicles like the Toyota Land Cruiser with the 1HZ engine, can be used with the 1HDT engine, though it's often recommended to use the stronger H151F transmission, especially with higher power outputs. The H150F is a 5-speed manual transmission, and the 1HDT is a 12-valve 4.2L turbocharged diesel engine.

Compatibility and Considerations:

• Input Shaft Spline:
  The H150F typically has a 21-spline input shaft, which may require a different clutch disc if swapping from a 1HZ with a different spline count.
  
  
• Power Handling:
  While the H150F can handle the 1HDT's power, it may be better suited for lower power tunes. If planning significant power increases (e.g., over 200HP and 600NM torque), the H151F is often recommended for its increased strength.
  
  
• Transfer Case:
  The H150F's transfer case may need to be swapped or modified depending on the specific application and desired transfer case setup.
  
  
• Clutch:
  The H150F will require a clutch disc designed for the 1HDT engine and the 21-spline input shaft, according to a parts website.

Alternatives:

• H151F:
  The H151F transmission is often preferred for 1HDT conversions due to its stronger construction and suitability for higher power levels.
  
  
• H152F:
  The H152F, found in later VDJ7# models, has taller gear ratios, and the transfer case may need to be swapped when used with the 1HDT.

In summary, while the H150F can be used with a 1HDT, it's crucial to consider the power output, potential need for a stronger transmission (H151F), and appropriate clutch components for optimal performance and reliability.

Hello,

It makes sense. It may be possible to trust AI on this one.

The comment on the spline count is useful.





Juan

 

[fullthrottle]

Well, so what the heck has been going on....

Yes a bit slack on the old keyboard lately. A big trip to Europe to watch the lad race got in the way a bit. But now, back to reality, work
However I still have the garage and old BJ to escape to.

I've been getting it ready for it's birthday. A heart transplant. I really like how you can completely dismantle the front end. Makes working on the engine so much easier.

 

[fullthrottle]

My shiny new heart arrived. It's had a lot of work done to it, So will make this truck fly....

 

[fullthrottle]

Have also ordered the 1HZ bellhousing from OZ. And once I pull the 3B I can check the input shaft to match up to the 1HDT and flywheel.

A place here in NZ supplies brand new flywheels for a reasonable price, plus a 300mm clutch setup than can be matched to the input shaft.
So it's not just a happy birthday, but also a Merry Christmas

 

[fullthrottle]

And......it's out...

 

[Eurasiaoverland]

Have also ordered the 1HZ bellhousing from OZ. And once I pull the 3B I can check the input shaft to match up to the 1HDT and flywheel.

A place here in NZ supplies brand new flywheels for a reasonable price, plus a 300mm clutch setup than can be matched to the input shaft.
So it's not just a happy birthday, but also a Merry Christmas

The H55F from behind a 3B will have a long 21 mm input shaft, the same spline pattern as a 1HZ clutch. However, it is significantly longer than the 1HZ input shaft for an H55F (which is still available new) so will push your already long 6 cylinder engine even further forward, unless you move the gearbox back.

AFAIK the 1HD has a different spline pattern and the standard 300 mm clutch will not work, so the choice is an aftermarket clutch, or using the 11" clutch disc from a 1HZ. Some Coaster buses had the 1HD-T and these used an 11" clutch, so you can get a Toyota clutch disc and uprated clutch cover if you want to stay OEM. I'm running this setup in my 15B-T.

 

[fullthrottle]

The H55F from behind a 3B will have a long 21 mm input shaft, the same spline pattern as a 1HZ clutch. However, it is significantly longer than the 1HZ input shaft for an H55F (which is still available new) so will push your already long 6 cylinder engine even further forward, unless you move the gearbox back.

AFAIK the 1HD has a different spline pattern and the standard 300 mm clutch will not work, so the choice is an aftermarket clutch, or using the 11" clutch disc from a 1HZ. Some Coaster buses had the 1HD-T and these used an 11" clutch, so you can get a Toyota clutch disc and uprated clutch cover if you want to stay OEM. I'm running this setup in my 15B-T.

Yeah, I was reading about the combinations available.
I'll await the housing to arrive and do some measuring to determine the exact combo. I do remember that some people had trouble with the 1HZ input shafts and the bearing housing is also different.

Anyway, what I have is a 21 spline, with this bearing housing, So I'll research it a bit more.

I will ask the place in NZ about the clutch as they said they could supply a 300mm, 21 spline clutch setup to go with the flywheel and H55. Apparently he was doing the same conversion....

1HDT Flywheel

 

[fullthrottle]

Ok, well I've removed the filthy gearbox and transfer from the truck. Will give it a birthday and rebuild it.
My new (2nd hand) 1HZ bellhousing arrived today and initial measurements show it to be 5-10mm shorter than the 3B one.

I will clean it up, take some more measurements and see how far the input shaft needs to move back so it sits snuggly into the crank spigot bearing.

Was thinking I could just Lazer cut a steel spacer to push the bellhousing out a little further.

Have also sourced a supplier that does the 1HDT flywheel with a 300mm, 21 spline clutch to go with it...

 

[Eurasiaoverland]

If you're going to rebuild it, why not just put a 1HZ input shaft in? They are still available new and will fit stright in if you have the later type H55F (10/85 onward), which I see that you do from an earlier picture of the input shaft bearing retainer.

 

[fullthrottle]

Yeah I could do. But it's all $$'s. Have spent enough already and will save some money for the rebuild.
A spacer is something I can do for free.

 

[Eurasiaoverland]

But then you need to move the transmission back, change propeller shafts, PTO drive shafts. Or modify the front to move the radiator forward.

 

[fullthrottle]

Do you happen to know what the gap is from the front of the 1HDT to the radiator support panel?
I'm not planning on moving the gearbox at all.

 

[Eurasiaoverland]

Here's a picture from an HZJ73. You can see it's a tight fit at the front, the fan blade must be very close to the radiator.

 

[fullthrottle]

Useful sources of info:

1HDT Flywheel and 300mm (21 spline) clutch suppliers

H55F Input Shaft & Bearing Retainer Tech/ID Pag

Rick's HDJ74 with 1HDT (Provides an idea on layout)

Iwan's Bj74 1hdt h55f combo

Diesel tachometer adapter

 

[fullthrottle]

One other thing I've discovered whilst examining the parts collection is that the H55 to 3B bell housing has the tachometer sensor in it.
Whereas my 1HZ bellhousing has no mounting point for such a sensor. Don't even know if it would work anyway as it's a different flywheel.
So will need to look at picking up the signal from elsewhere on the 1HDT.

There seem to be lots of solutions out there. This was interesting...
Diesel tachometer adaptor from JRP