Defender V8 3.9EFI manual to automatic

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Becks Bear

Active Member
Posts
258
Location
Northern Ireland
I have a 4HP24EH monster box stage two built by Ashcroft’s and was fitted to my off roader that is a 300dti and has done 200miles maximum. It has been dried stored for two years full of oil.

At present in my 1989 3.9EFI V8 defender I have an LT85 gearbox that is making one hell of a racket in 5th gear and when sitting idling and I believe it’s the lay shaft but not sure. This box was, rebuilt many miles ago by the previous owner of the 90, it was at that time rebuilt by Ashcroft’s.

Now the questions if I fit the auto box into the V8 what parts do I need


Things I know I need, again good info from Dave at Ashcroft’s very helpful


V8 bell housing to fit RRC 3.9.

Flex plate and starter ring to suit RRC 3.9.

TC to suit the 4HP24EH auto box.

Kick down cable I have from the 300tdi just fit a shorter cable from Ashcroft’s


Things I need to find or advice to work around this

Kick down linkage from the plenum chamber, I can only see goggling this linkage for crabs unless they are the same

What oil cooler to use and where is the best place to position it

I have the disco 1 gear shift and cable but not in the best condition, would a gear shift from a Discovery 2 also do the job


Any other advice or any parts that I need


Very best regards Ivan
 
I have a 4HP24EH monster box stage two built by Ashcroft’s and was fitted to my off roader that is a 300dti and has done 200miles maximum. It has been dried stored for two years full of oil.

At present in my 1989 3.9EFI V8 defender I have an LT85 gearbox that is making one hell of a racket in 5th gear and when sitting idling and I believe it’s the lay shaft but not sure. This box was, rebuilt many miles ago by the previous owner of the 90, it was at that time rebuilt by Ashcroft’s.

Now the questions if I fit the auto box into the V8 what parts do I need


Things I know I need, again good info from Dave at Ashcroft’s very helpful


V8 bell housing to fit RRC 3.9.

Flex plate and starter ring to suit RRC 3.9.

TC to suit the 4HP24EH auto box.

Kick down cable I have from the 300tdi just fit a shorter cable from Ashcroft’s


Things I need to find or advice to work around this

Kick down linkage from the plenum chamber, I can only see goggling this linkage for crabs unless they are the same

What oil cooler to use and where is the best place to position it

I have the disco 1 gear shift and cable but not in the best condition, would a gear shift from a Discovery 2 also do the job


Any other advice or any parts that I need


Very best regards Ivan
Hello
Please any info or help available?

cheers Ivan
 
Hi Ives:D.

So you have given up "big Red" then?

From what I know.

If your auto box is stage 2 it will take the biggest of the TCs (4 bolt) which maybe more suitable as you 3.9 runs the Tornado chip;).
Will that fit in the RRC bellhousing I don't know, but there are plenty of ZF4 HP24 bellhousings available with ring gear and flex plate.
You need to check what oil cooler fittings at the gearbox, are they the HP22 or HP24 as they are a different size. But as for the cooler, up front behind the grill and go to your local hydraulic hose place. Pretty sure any disco or RR box cooler can be fitted up front.

As for the kick down, don't know but pretty sure it would be available RR/Disco 4.0 maybe?
As for the gearshift they look the same, Does your box have the XYZ switch as you will need some wiring mods to get reverse lights I think.

Gearbox mounts?


You retired yet?

J
 
Hi Ives:D.

So you have given up "big Red" then?

From what I know.

If your auto box is stage 2 it will take the biggest of the TCs (4 bolt) which maybe more suitable as you 3.9 runs the Tornado chip;).
Will that fit in the RRC bellhousing I don't know, but there are plenty of ZF4 HP24 bellhousings available with ring gear and flex plate.
You need to check what oil cooler fittings at the gearbox, are they the HP22 or HP24 as they are a different size. But as for the cooler, up front behind the grill and go to your local hydraulic hose place. Pretty sure any disco or RR box cooler can be fitted up front.

As for the kick down, don't know but pretty sure it would be available RR/Disco 4.0 maybe?
As for the gearshift they look the same, Does your box have the XYZ switch as you will need some wiring mods to get reverse lights I think.

Gearbox mounts?


You retired yet?

J
Cheers Jon
i have most information i think i need, its a winter project
yes big red still on the go in the forest and events as much as i can get to........................cheers Ives
 
I have a 4HP24EH monster box stage two built by Ashcroft’s and was fitted to my off roader that is a 300dti and has done 200miles maximum. It has been dried stored for two years full of oil.

At present in my 1989 3.9EFI V8 defender I have an LT85 gearbox that is making one hell of a racket in 5th gear and when sitting idling and I believe it’s the lay shaft but not sure. This box was, rebuilt many miles ago by the previous owner of the 90, it was at that time rebuilt by Ashcroft’s.

Now the questions if I fit the auto box into the V8 what parts do I need


Things I know I need, again good info from Dave at Ashcroft’s very helpful


V8 bell housing to fit RRC 3.9.

Flex plate and starter ring to suit RRC 3.9.

TC to suit the 4HP24EH auto box.

Kick down cable I have from the 300tdi just fit a shorter cable from Ashcroft’s


Things I need to find or advice to work around this

Kick down linkage from the plenum chamber, I can only see goggling this linkage for crabs unless they are the same

What oil cooler to use and where is the best place to position it

I have the disco 1 gear shift and cable but not in the best condition, would a gear shift from a Discovery 2 also do the job


Any other advice or any parts that I need


Very best regards Ivan
1. The kick down cable attaches via a bracket to the throttle along with the existing throttle cable.

2. The 3.9 auto gearbox has two coolers one on the side of the radiator (the opposite side on the rad to the engine oil cooler), the other auto cooler is a small stand alone item positioned horizontally at low level in front of the rad, this is inline with the auto box high temperature warning sensor.

3. The auto selector for a D1 is via a short cable and rod, the D2 is cable direct, I believe.
 
1. The kick down cable attaches via a bracket to the throttle along with the existing throttle cable.

2. The 3.9 auto gearbox has two coolers one on the side of the radiator (the opposite side on the rad to the engine oil cooler), the other auto cooler is a small stand alone item positioned horizontally at low level in front of the rad, this is inline with the auto box high temperature warning sensor.

3. The auto selector for a D1 is via a short cable and rod, the D2 is cable direct, I believe.
thanks discool
i have found the bracket on line but boy is it expensive for what it does

now have the correct size threads required for the auto box so i can get the correct hoses made, so i will go with two coolers or one big cooler

i cant find for love nor money a complete D1 auto selector with the lights that show up the gears, the one i have i might have to rework it when i get back home


cheers ivan
 
thanks discool
i have found the bracket on line but boy is it expensive for what it does

now have the correct size threads required for the auto box so i can get the correct hoses made, so i will go with two coolers or one big cooler

i cant find for love nor money a complete D1 auto selector with the lights that show up the gears, the one i have i might have to rework it when i get back home


cheers ivan
FTC3908 is the part number for the whole selector kit, it costs more than my D 1 is worth.


The early RR may work, its not that dissimilar from the disco, the RR has a buttons on the side of the selector leaver, the disco has a lever underneath.
 
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