necessary changes? 1hz to 1hdt

Pither80 · **Posted:** Mon Jun 27, 2011 10:15 pm

Hey everyone,

Ive got about a week before my 1hdt arrives, so i thought i better get my arse into gear and organise everything i will need.
The 1hdt is from a 1996 gxl, and my car is a 1990 1hz gxl.

The things ive come up with so far is:
-New mounts (1hz and 1hdt same?)[/color][/color]

http://www.ebay.com.au/itm/TOYOTA-LANDC ... 19bfe9794f

http://www.ebay.com.au/itm/Engine-Mount ... 415b0bf3d4

-New exhaust (going a 3in system)
http://www.ebay.com.au/itm/Landcruiser-80-Series-HDJ80-Wagon-3-High-Flow-exhaust-/130530575820?pt=AU_Car_Parts_Accessories&hash=item1e643a85cc

http://www.ebay.com.au/itm/LANDCRUISER- ... 2564cfa262

-new clutch (this where im stuck)
http://www.ebay.com.au/itm/Landcruiser- ... m11562b07f

-new radiator (copper/brass or alloy/plastic)
http://www.ebay.com.au/itm/Toyota-Landc ... 45fb5a2ff7

http://www.ebay.com.au/itm/TOYOTA-LANDC ... 4a9eb949d4

http://www.ebay.com.au/itm/TOYOTA-LANDC ... 4a9cf27fd9

-hoses,belts,fluids, oils ect

is there anything i have missed?

Ive chucked up some links that i was thinking of buying, check them out at give me some feedback/advice if possible

My major issue is the clutch. Ive heard the 1hdt have a 300mm clutch, while the 1hz is 275mm?
What do people generally do with this? use a 300mm flywheel and run the bigger clutch or bolt the 1hz flywheel on and use a 1hz clutch. I ask this because my 80 apparently had a new clutch fitted 5 months ago, before the previous owner cooked the motor. In theory that clutch should be in great nick. The head on the engine warped and caused oil to leak out between the head and the block. Ivbe heard that this clutch may be stuffed due to the oil leaking down and seeming through onto it.

Im pretty sure my engine is coming with the flywheel, as it comes as it is outta the car nothing unbolted from it.
So with all this in mind im thinking i would be better getting a new 1hdt 300mm clutch, howver im struggling to find one online, any ideas?

Pete. R. · **Posted:** Mon Jun 27, 2011 10:33 pm

Change to a HD clutch, I used Terain Tamer. Nothing else required. Do the other mods in slow time.

dkr059 · **Posted:** Tue Jun 28, 2011 5:47 am

The 1HDFT runs a different gearbox I'm not sure on th hdt but I imagine it would they have more splines on the input I think, hopefully your pressure plate will bolt up to the new flywheel

shanegtr · **Posted:** Tue Jun 28, 2011 9:35 am

the engine mounts are physically identical, I belive its just the rubber compound thats different so you shouldnt have any issues there

thehardroad · **Posted:** Tue Jun 28, 2011 5:48 pm

Hi mate,

The 1HZ and 1HDT have a different gearbox. There are some different ratios but the difference that matters in this case is the input shaft on the gearbox; the spline count is different. The 1HZ driven plate has a 275mm OD, 29mm ID and 21 splines, the 1HDT driven plate has a 300mm OD, 32.4mm ID and 14 spline. I used a 1HDT flywheel (I don't know if it's different to the 1HZ flywheel) and pressure plate to get the 300mm diameter and used an NPR Isuzu truck driven plate that had the correct 29mm ID and 21 spline count and the required 300mm OD, try a R12065W driven plate. It was easy to get, I rang Clutch Industries direct to sort that parts and they found me a dealer nearby to buy it from. Their website will let you find the parts you need also.

Other than that it was plug and play other than the exhaust.

Cheers
Muz

thehardroad · **Posted:** Tue Jun 28, 2011 5:50 pm

Oh, and a 1HDT aircleaner lid and pipe from it to the turbo wasn't all that dear and made the job nice and factory.

Cheers
Muz

Pither80 · **Posted:** Tue Jun 28, 2011 8:20 pm

Really I was under the impression that the Gearboxes were the same! Dam!

So muz what your saying is if I use the 1hdt flywheel that will already be mounted to the 1hdt, buy a new 1hdt pressure plate and the izuzu driven plate I can mount the 1hdt to my gearbox?

Will the ratios create any issues?

You say that the exhaust is different, if I go one of these 3 inch systems it should all mount up?

Pither80 · **Posted:** Tue Jun 28, 2011 8:25 pm

Oh and muz I have the 1hdt airbox lid coming, the lid with the down facing elbow to connect to the turbo.

The 3 in exhaust isn't a mod more a neccesity as I don't think my factory 1hz exhaust will bolt up so I figured I may as well get a new one seemings I'll have to chase one up anyway.

The radiator is stuffed I'n mine from when he cooked the 1hz and just seems old. Has a few pin holes and the plastic tanks are cracked. Am I better off upgrading to copper/brass or staying with alloy/plastic?

Pither80 · **Posted:** Tue Jun 28, 2011 9:39 pm

Ok muz ive found this information on the clutch industries web site:

Kit No. R1242N
Dimensions: 300mm X 21T X 29mm
Cover Assy: R1200-509
Clutch Plate: R12065W
Release Bearing: GSB484

Click here for Performance Options

Kit No. R1242N
Dimensions: 300mm X 21T X 29mm
Cover Assy: R1200-509
Clutch Plate: R12065W Release Bearing: GSB484

Click here for Performance Options

Kit No. MR1242N
Dimensions: 300mm X 21T X 29mm
Cover Assy: R1200-509
Clutch Plate: MR12065W
Release Bearing: GSB484

So the part number listed above is what i need? i then need to buy a 1hdt pressure plate and then it will all mate up to my gearbox and the 1hdt flywheel.

Can the above part number be purchased seperately (as it just the R12065W clutch plate)? or do i need to buy that whole kit.

any idea what the clutch will end up costing me?

as in R12065W clutch plate, 1hdt pressure and thrust bearing?

Pither80 · **Posted:** Tue Jun 28, 2011 9:41 pm

Kit No. R1087N
Dimensions: 300mm X 14T X 32.4mm
Cover Assy: R1200-506
Clutch Plate: R12064W
Release Bearing: GSB434

Click here for Performance Options

Kit No. MR1087N
Dimensions: 300mm X 14T X 32.4mm
Cover Assy: R1200-506
Clutch Plate: MR12064W
Release Bearing: GSB434

This is the 1hdt clutch kits, so ill need a pressure plate from a kit like this?
what realase bearing to i purchase?

shanegtr · **Posted:** Tue Jun 28, 2011 11:21 pm

Pither80 wrote:

Really I was under the impression that the Gearboxes were the same! Dam!

So muz what your saying is if I use the 1hdt flywheel that will already be mounted to the 1hdt, buy a new 1hdt pressure plate and the izuzu driven plate I can mount the 1hdt to my gearbox?

Will the ratios create any issues?

You say that the exhaust is different, if I go one of these 3 inch systems it should all mount up?

Physically the boxes are the same, just different 1st & 2nd gear ratios. Wont create any issues - from what I've read some prefer the 1hz ratios

thehardroad · **Posted:** Wed Jun 29, 2011 5:43 pm

Pither80 wrote:

Oh and muz I have the 1hdt airbox lid coming, the lid with the down facing elbow to connect to the turbo.

The 3 in exhaust isn't a mod more a neccesity as I don't think my factory 1hz exhaust will bolt up so I figured I may as well get a new one seemings I'll have to chase one up anyway.

The radiator is stuffed I'n mine from when he cooked the 1hz and just seems old. Has a few pin holes and the plastic tanks are cracked. Am I better off upgrading to copper/brass or staying with alloy/plastic?

Hi mate,

I used a R1200-506 Pressure plate and GSB434 thrust bearing, which are 1HDT items. I used a R12065W driven plate, which is the Isuzu part.

I'm not sure on the exhaust but I am pretty sure the cars are basically the same so if you bought a 1HDT exhaust it would all bolt straight on.

After much deliberation, I bought an aftermarket radiator of the same construction as the Toyota item ie. plastic tanks. So far it's doing the job. I can't remember where I got it from though.

As Shane said, the 1HZ gearbox has lower first and second, I'm happy with that.

I put in new engine and gearbox mounts and all the hoses and stuff while I had the thing in bits, but that's up to you.

Yep, the airbox lid with the outlet pointing down is the go I think; it's just neater.

Cheers
Muz

Pither80 · **Posted:** Fri Jul 01, 2011 1:13 pm

Do these prices seem fair.

R1200-506. $400
Gsb434. $110
R12065w. $250

rezpkt · **Posted:** Fri Jul 01, 2011 7:06 pm

Watching this thread with a vested interest!

As for the 1HZ/1HDT exhaust mounts from memory 1 or 2 exhaust mounts are slightly different (middle and back? - can check) but very easy to modify.
FYI I'm running factory ct-26 turbo with all 1HDT parts (except oil feed) on my 1HZ.

An alternative cheaper 3" exhaust system is one of these that quite a few people run.
Just cut the middle muffler out and run 3" straight through, it's a perfect note with good performance.

http://www.ebay.com.au/itm/TOYOTA-LANDC ... 1c1a99b847

Best of luck and look forward to future posts

Pither80 · **Posted:** Fri Jul 01, 2011 8:03 pm

That sounds pretty interesting mate, did you track down all the 1hdt parts and just swap them over onto your 1hz? hows it go?
Your 80's looking pretty beffy in your pic! Cant wiat to get some lift and tyres onto mine! hopefully not to long after its on the road.

Also mate watch my thread in the projects thread, thats where ill be posting up all the install pics and stuff

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