The Range Rover / Landrover Gearbox Swap information Page

Ive created a dedicated page to try and collect as much info as possible about the different gearbox combinations that can be used or considered in a range rover. If you have any relevant information or photos, please send them in. Comments, questions or got answers? Please use the Mez Forums to get in contact or chat about this page.

FAQ - Updated 16/07/2011

Q)Can I use a 2WD box with a propshaft?

A) Possibly - take a look at this website: Rakeway Engineering They make some lovely parts for the LT230, which includes parts to allow you to attach a 2wd box using a UJ and also parts to shorten the box by 70mm - which may save moving the box any further back (4L80e conversion). Q)Can I use a TH400 automatic gearbox?

A)Possibly. You need to check if the front prop will hit the gearbox.

Having made a 4l80e fit, a th400 should fit also.

Q)Can I use a 4L80e automatic gearbox?

A)Yes! - Using a Marks 4WD adapters. Photos of the adapter can be found on my 4l80e information page

2008 Update: I'm also making my own adapter for the 4L80e, information can be found here:

Q)Can I use a TH350 Automatic gearbox?

A)YES -Ive done it - see See my conversion

Q)Can I use a TH700R4 Automatic gearbox?

A)YES. You need to extend the distance between the box and transfer case to get the front prop to clear the side of the case. This means (at least in two cases i know of) you need to move the transfer box backwards and extend the front prop and shorten the rear prop. If you had enough room at the front, you could just move the engine forwards (3") I have successfully fitted one see:700r4 upgrade

Main issue with the 700r4 is that it doesn't handle high toque / horsepower very well (Did I mention that i'm running twin turbos on a 5.7L V8). Im now rebuilding my third box using 5 pinion planetaries and the Torque drive Engineering (TDE) drum and shell package. Details Here

How do you make the coupler shaft?

This is essentially the 'trick' to the conversion. You get a LT230 coupler shaft then machine and weld it to a TH350 propshaft yoke. I'm now posting the information, for the benefit of others - plus I stumbled accross the orginal box with the part number for the shaft the otherday.

You need an FTC5090 coupler shaft:

And either a splined yoke or an old propsaft with the correct splines for the gearbox:

you cut the splined section from the Yoke and then machine the internal diameter of the couple shaft so the splined yoke section slides in a little to provide a register. Then TIG weld it all the way round. It should look like this:

Sounds very easy, but that coupler shaft is hardened and is difficult to turn on the lathe. So now you know the 'secret'

Q)What about the HP22 4 Speed auto-box and a chevy?

A)The HP22 only handles 280FT/Lb (Nm?) of torque. Also, the later ones relied on the ECU to manage gear changes. (you need a 1991-1994 non electronic box i think)

Q)Which transfer Box?

A)I used a 1003:1 LT230 Box that came from the 3 speed Range rover (which had the torque-flyte? box in it). With 35" tyres the gearing is quite tall. 3000RPM is about 75-80MPH. I think any LT230 box will do though. I'm also now trying a 1.19:1 transfer box in it with the 700r4 to see how it goes. The Later borg-warner chain-drive box looks different, so i dont know if you could use it.

Q)Can i purchase the adapter from you?


Please dont email me asking to sell the conversion, its quite easy to make your own following the details in these pages.

Consider the following:

My adapter requires the original adapter that Landrover used to fit the 3 speed auto to the 3.5 Range rover circa 1982 onwards. I also used the LT230 transfer box from this vehicle (1003:1) ratio. Click Here to see a picture of it

I believe the part number is FRC5622.

You need to change the front prop-shaft to the thin solid type. If you dont, the prop may hit the transmission oil pan.

You need to fabricate the exhaust system - i *Belive* my headers are from a '79 chevy blazer(mine came free with the engine and the engine was from a blazer - so i'm only assuming)

You need to Fabricate The engine mountings, plus varios other brackets for alternator, PAS pump etc

Make sure you cooling system is up to scratch - I added an extra row to the standard 3.5 EFI rad.

Think about your brakes - i fitted vented disks to the front

Think about your transmission, i'm running 24spline half shafts and 4 pin diffs


The output shaft of your TH350 needs to be the "short" type. It sticks out about 3-6" front the end of the box WITH THE EXTENSTION HOUSING REMOVED. Dont confuse this the VERY short 4x4 type that dosn't stick out at all.(This is too short). Also note that the output shaft then needs to have about 1" hack-sawed of the end of the shaft, potentially rendering it useless for other purposes. (Or at least will need the shaft replacing)

Other related links:

Marks Adapters List TH400 and 4L80e adapters.

This is a very similar to mine, but using a 700r4 which isn't supposed to be possible, looks like he cut the gearbox to get clearance. (plus later transfer box)

Someone else whos done a 700r4 conversion

Legal stuff::

All the information posted here is for my personal reference only. The author makes no recommendations on suitability for installation on any vehicle whatsoever.