These things (late 80s 750 BMWs) use ZF slushboxes don't they?
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And fetch peanuts. And would probably fit under the nose of a Defender or Tomcat/Bowler with a little persuassion. And are a stupidly smooth way of delivering 300 brake.
Anybody got some approximate engine dimensions?
Anybody know how different a car-derived ***22 ZF box is to a ***22 ZF box from a Rangie/Disco V8?
Which bits need to be chopped and changed to bolt a car-derived box onto an LT230, or which bits need to be chopped and changed to bolt a
750 motor to the front of a Land-Rover main 'box and have it change gear properly?
the ZF 4HP22 autobox must supposedly be the same as far as torque specifications apply either when used for a road going or an off road going vehicle.
The upgraded version which can withstand more torque is called 4HP24 and is the one used on the Range Rover 4.6. All other variants of LR vehicles of this or previous model years use the 4HP22 autobox. (apart from the 4.6 engined RaRo P38A)
Some people say that the same autobox (4HP22) may be used without a problem on either a 3.5 or a 3.9 V8 or even a Tdi (200 or 300) engine. I have not been able to confirm that for some years now. Ashcroft Transmissions say that the version of the 4HP22 is different between engine types and variants but users who have transplanted autoboxes from V8 engines to Tdi engines say they have absolutely no problem.
As for the maximum torque allowance I would say that the general guideline may lay between the torque output of the 4.0 and 4.6 V8 Range Rover P38 engines. The 4.0 engine with its 320 Nm of torque uses the 4HP22. The more torquey 4.6 engine with almost 380 Nm of torque uses the 4HP24.
So if the engine you plan to use (nice engines those BMW V12, they were also used on the MacLaren F1 !!!!) delivers more than 380 Nm of torque I would suggest you use an autobox from a RaRo P38. But this may require some sort of electronic control if I remember well.
Ultimately I dunno the answers but suspect the simplest option would be similar to that I've just applied to Percy. I.e. remove 4.2 Jag lump, swap bell housing for the SD1 BW66 to V8 one, refit V8.
Except obviously you will need the bell housing relevant to the zf autos in your case. That way you don't need stress about faffing with transferbox mountings / compatibility.
The V8 now sat in Percys engine bay looks positively little, I only hope it worth all the faffing.
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