v8 auto box into 300tdi defender

[Bazzle218]

Hi one and all. I know the best conversion is to drop a 300 tdi auto into the 110, ute Unfortunatley I have access to a few v8s boxes but no diesel boxes. Has anyone done this and what was involved. I can do most work myself so thats not a problem. What parts do I need and mods to the box. Baz

[justinc]

Hi one and all. I know the best conversion is to drop a 300 tdi auto into the 110, ute Unfortunatley I have access to a few v8s boxes but no diesel boxes. Has anyone done this and what was involved. I can do most work myself so thats not a problem. What parts do I need and mods to the box. Baz

Baz,

The V8 box is different in a few areas, that IMO make it a bit of a pain to change to diesel 'spec'. Firstly, the obvious bellhousing and pump housing, but less obvious is the cam profile for the throttle (kickdown) cable is way different, and the governor is a different weight to allow lockup etc at a lower road speed. (Not much, about 10km/hr so you COULD just leave that, the V8 is around 85km'hr, the diesel 75km/hr. Note that in a 110 with a 1.410:1 high range you will have even lower road speed upshifts etc, like 65km/hr to 70km/hr for converter lock in 4th)

The differences in the valve body I haven't been able to quantify, they may be unimportant , affecting shift pressure (Harshness?) etc maybe.

The cam can be changed out for the relavent diesel profile one, but this involves removal of the valve body, and a shaft that can't be done in the vehicle as there is not enough clearance.

JC

[Casper]

Baz,

The V8 box is different in a few areas, that IMO make it a bit of a pain to change to diesel 'spec'. Firstly, the obvious bellhousing and pump housing, but less obvious is the cam profile for the throttle (kickdown) cable is way different, and the governor is a different weight to allow lockup etc at a lower road speed. (Not much, about 10km/hr so you COULD just leave that, the V8 is around 85km'hr, the diesel 75km/hr. Note that in a 110 with a 1.410:1 high range you will have even lower road speed upshifts etc, like 65km/hr to 70km/hr for converter lock in 4th)

The differences in the valve body I haven't been able to quantify, they may be unimportant , affecting shift pressure (Harshness?) etc maybe.

The cam can be changed out for the relavent diesel profile one, but this involves removal of the valve body, and a shaft that can't be done in the vehicle as there is not enough clearance.

JC

JC, from my experience with this box, the govenor on both should be set to lock up at 80kms with the 1.004 TC but you are correct with the kick down cable but they could be changed in car in a Deefa as you could pull the tunnel out unlike a Disco

Shift pattern I believe is controlled by the valve body and I have driven 300Tdi's with the V8 valve body and they hold gears way too long to where power starts to drop off and economy really suffers.

The pump and housing is the biggest hurdle as previously mentioned and the bell housing is an easy changed over but you ahve to put a 300 TDI converter and drive plate aswell as your V8 one is not compatible.

Cheers Casper

[Bazzle218]

thanks folks, Given the above information i will wait out on a diesel box. Justin I seem to recall that you recomended I stay with the defender TC if i go to auto, is that the case.

[Casper]

thanks folks, Given the above information i will wait out on a diesel box. Justin I seem to recall that you recomended I stay with the defender TC if i go to auto, is that the case.

Yes I would as with the 750/16's (approx 32") it's beeter to keep the Deefa TC.

I ran 235 85 16's on my Disco with the Disco TC and it struggled towing and on hills but I fluked getting a deefa case second hand and it made a heap of difference to the drivability.

Cheers Casper

[twitchy]

With all these supposed differences why does the manual show you how to put a TDi in front of the V8 auto?? Apparently Land Rover seem to think it will work.
The main difference in bolt up ( not talking about the internals here) is the gearbox to TC adapter is longer in the TDi than the V8, the bell housing is also a different length & needs to be notched in one place so it will bolt up.

Why would the pump be different??? the oil has still got be the same pressure to operate the transmission... I understand the characteristics of the torque converter being different.
The valve body will be set differently.

I will investigate some of these issues next weekend anyway, I can then say what will & wont fit where!!!!!!!!

[langy]

If I may add a little bit I found on the subject:

Ashcroft Transmissions ( actually a member here too..Ashtrans) have a section on using an auto from a v8 with the 2.8 tgv /300tdi - and they mention a kit which appears to be one or two adaptor plates, the small mod that Mr T mentioned - and not too much else. They compare the 3 sizes of torque converters, and their logic is - you have the torque, you may as well use it. Apparently, if you bolt on a TC from a 4.0/4.6 with a lower stall speed, and the 4HP22 ( or better a 4HP24 etc) with a 300tdi /2.8, the auto box responds well, with better conversion of torque to motion. They do not mention any changing of the interior of the auto ( with the exception of fitting '24 parts to upgrade the '22 if you were intending competition).

the information about the adaption is at the lower end of the webpage

Ashcroft Transmissions - ZF4HP22

[Casper]

With all these supposed differences why does the manual show you how to put a TDi in front of the V8 auto?? Apparently Land Rover seem to think it will work.
The main difference in bolt up ( not talking about the internals here) is the gearbox to TC adapter is longer in the TDi than the V8No thats not the case, I have used the trans to TC shaft from a V8 in my 300Tdi and Vice versa, the bell housing is also a different length & needs to be notched in one place so it will bolt up.

Why would the pump be different???[COLOR="rgb(65, 105, 225)"]Vibrations, the 300Tdi trans pump is Isolated I have been told but I have not seen it myself so I can't be 100% on that.[/COLOR] the oil has still got be the same pressure to operate the transmission... I understand the characteristics of the torque converter being different.
The valve body will be set differently.

I will investigate some of these issues next weekend anyway, I can then say what will & wont fit where!!!!!!!!

If I may add a little bit I found on the subject:

Ashcroft Transmissions ( actually a member here too..Ashtrans) have a section on using an auto from a v8 with the 2.8 tgv /300tdi - and they mention a kit which appears to be one or two adaptor plates, the small mod that Mr T mentioned - and not too much else. They compare the 3 sizes of torque converters, and their logic is - you have the torque, you may as well use it. Apparently, if you bolt on a TC from a 4.0/4.6 with a lower stall speed, and the 4HP22 ( or better a 4HP24 etc) with a 300tdi /2.8, the auto box responds well, with better conversion of torque to motion. They do not mention any changing of the interior of the auto ( with the exception of fitting '24 parts to upgrade the '22 if you were intending competition).

the information about the adaption is at the lower end of the webpage

Ashcroft Transmissions - ZF4HP22

I don't know about Ashcrofts but they are also talking about the UK versions of things, quite often there are changes on OZ spec cars and quite often the trans is one of them due to our harsh driving conditions and extreme distances we travel.

What may work for them may not work for us but as far as I have seen they are the experts so possibly Ashtrans can elaborate.

Cheers Casper