Thread: Dead ZF 4HP22

Where are you Dave?

Methinks Dave hails from Ashcrofts in the UK. Dave I want to build a stump puller using a strengthened ZF4HP22 & LT230 (going in a D1) to take >300HP and 300 lbs ft @ around 2K (measured @ the wheels).

Is a strengthened ZF up to that? Is there anyone in Australia doing this work using your upgrade parts?

Cheers

Simon

Originally Posted by cockie55

Methinks Dave hails from Ashcrofts in the UK. Dave I want to build a stump puller using a strengthened ZF4HP22 & LT230 (going in a D1) to take >300HP and 300 lbs ft @ around 2K (measured @ the wheels).

Is a strengthened ZF up to that? Is there anyone in Australia doing this work using your upgrade parts?

Cheers

Simon

There are a couple of places down in Melb that can do these mods but the price starts at $3k + mods as most of them require a full rebuild.

A&B used to Dyno test all their autos (back when my mate was working there) before they ship them out so you know that it should be up to your specs when you get it.

A good clewy auto repairer is quite capable of rebuilding the ZF's and I have seen one put together without all the special tools but it makes for hard work and because of tolerences they are a bit f hit and miss if they will work properly once you get them back together and you wont know until you have got it going.

I would go see a rebuilder up your way or talk to others up in brisvagas about where is best and then go talk to them about the mods.

Originally Posted by cockie55

Methinks Dave hails from Ashcrofts in the UK. Dave I want to build a stump puller using a strengthened ZF4HP22 & LT230 (going in a D1) to take >300HP and 300 lbs ft @ around 2K (measured @ the wheels).

Is a strengthened ZF up to that? Is there anyone in Australia doing this work using your upgrade parts?

Cheers

Simon

Hi Simon,

to me the daddy of the ZF is :

big converter :



stage 2 upgrade with 4HP24 internals, info here :

Ashcroft Transmissions

and control it with the compushift :

Ashcroft Transmissions

if you buy this lot from us you are looking at around £ 2000 or I can talk either you or your autobox shop through which 24 donor box you require.

we have built quite a lot of these and the only ones we have had back are ones that have failed due to either oil pipes being torn off or water damage from severe wading, I don't remember seeing one back due to a failure from excess power but there's always a first time !

Dave

Thanks Dave.

That Compushift looks as though it gives the 4HP22 a new lease on life. I take it the larger converter will solve heat issues or are upgrades to pump (if possible to fit) and cooler recommended?

No problems I assume matching larger converter to a D1?

Is it possible to swap out a hydraulic 4HP22 for the electronic 4HP24 with or without a Compushift? Or does the 24 require an electronic transfer, requires sensor inputs that pre Gem ECU's (D1's, RR Classics) don't output and or the 24 is larger and just won't fit anyway without other mods?

Simon

FWIW IMHO, the larger converter wont solve the heat issue but it will mitigate them a little, the only cure for the heat problem is better cooling for the box and a bit more oil in it to make up for the extra capacity of the bigger TC and cooler.

A better flowing pump also helps but you have to watch you dont go over what the existing pressure regulator can deal with or you can blow seals and clutches inside the box.

Originally Posted by Blknight.aus

FWIW IMHO, the larger converter wont solve the heat issue but it will mitigate them a little, the only cure for the heat problem is better cooling for the box and a bit more oil in it to make up for the extra capacity of the bigger TC and cooler.

A better flowing pump also helps but you have to watch you dont go over what the existing pressure regulator can deal with or you can blow seals and clutches inside the box.

Bigger convertor will help with heat, when putting HP through as it stops the convertor flaring

Also a larger lockup clutch

when your slugging it up a hill in 3rd unlock your still going to heat it up... thats part of how a TC works..

It will take longer to cook it tho.