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Discussion Starter · #1 ·
Hey folks...

I have a 2003 Discovery with a 300tdi motor swap. Been working here and there to boost the power, but I have a question about the transmission.

Pretty sure I have the original ZF transmission from when it was a gas engine. Is there a difference for the transmission on a diesel version? UK Version?

Just wandering if a tranny swap would significantly increase my drivability (gearing etc)

thanks,
 

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Yes, different bellhousing, input shaft, torque converter, shift setup between diesel and V8.
 

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The real difference is the shift points and the governor and the weight.
I've converted them before to get the shift points correct.
 

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Oh forgot to mention with the 2003, isn't the transmission electronic?
In that case you would need the diesel software instead of the gas engine software.
But I am only providing hints as I am no expert on late discoveries.
The tips in post 4 were if you had an early V8 transmission from a disco I.
 

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Oh forgot to mention with the 2003, isn't the transmission electronic?
In that case you would need the diesel software instead of the gas engine software.
But I am only providing hints as I am no expert on late discoveries.
The tips in post 4 were if you had an early V8 transmission from a disco I.
Good point. A Disco 2....

You can't have a 300TDI mounted to a Disco 2 transmission so it was probably swapped with a proper 300TDI transmission. Does anything work on the Disco? Getting the BCM to function is not a small ask.
 

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Ah. Complete Frankenrover. You will need to have someone look in person it will be too complex to figure out what was done over the internet.
 

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ideally you’d have a conversion that was from an auto D1 tdis chopped in half

with the right bellhousing you can put basically any engine that came with a 4HP. i’ve even seen D24s swapped up before
 

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Depends on what you have. As Robert said the V8 trans sucks behind a diesel, its all wrong. If you have a 4hp22 with kick down cable,you have to switch the governor in the rear of the transmission so that it works properly with the diesel, changes all the shift points etc. Probably easier to swap trans to proper one if thats the case.
If you have the later 4hp22eh you can swap the controller to the Compushift one and reprogram
the shift points etc with the Compushift software. This is a package Ashcroft offers. About to try a 4hp24eh behind the Cummins 2.8 and play with the software and see if we like it.
 

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Discussion Starter · #11 ·
It’s got a kick down cable so I think it’s the 4hp22. Just not sure it’s for diesel or gas.
 

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Discussion Starter · #12 ·
Is there something I could take a picture of and post it here that would tell us if it’s diesel or petrol?
 

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It wouldn't really matter, what really matters is what you're comparing it to. I've driven several different tdi discos but only 1 auto, it was slower. In Colorado, I can't imagine that's enjoyable to drive. But really it comes down to what you're comparing it to
 

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Let's see, hmmm, what engine would be a good one for comparison?
 

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Hey folks...

I have a 2003 Discovery with a 300tdi motor swap. Been working here and there to boost the power, but I have a question about the transmission.

Pretty sure I have the original ZF transmission from when it was a gas engine. Is there a difference for the transmission on a diesel version? UK Version?

Just wandering if a tranny swap would significantly increase my drivability (gearing etc)

thanks,
Hello, I have a trans out of a UK 300TDI Disco in my Defender, attached is a picture of the serial number. Not sure if these helps identify your trans or not? The Defender is currently stripped down having a bulkhead replaced so I have good access if you want to see anything else. I like the 300TDI Auto combination, its great for the city driving that I do.
 

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You can pull the little 3-bolt inspection cover off the bottom and see how much room you have inside the bell housing. The diesel torque converter is much smaller in diameter then its V8 counterparts which would leave a lot of excess room inside the bell housing cavity.
 
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