Offroad-Express

hi team,
i have recently acquired an isuzu 4jg2 motor and 5 speed gearbox. i am mulling over the idea of putting it into my stage 1 (series 3). it looks as though it will physically fit ok. the only big issue i may have is that the rear driveshaft comes out of the transfer box in the centre but the landy rear axle is of course offset. i have read up on the lvvta requirements but don't understand whether this may be a problem.
has anybody had any experience with this??

Technically, so long as the U-joints are in phase and working within their operational limits in terms of angle, you shouldnt have problems with vibrations. Since its a LWB the rear driveshaft will be quite long which will make it even easier.

ie the transfer case output flange and diff pinion flange centrelines need to be perfectly parallel.

I've just been through this, I had both flanges parallel and an angle of 15° on the uj's on my rear driveshaft. Under load everything was fine but on coast there was a concerning whir coming from the gearbox. It turns out that the maximum angle the uj can be depends on the driveshaft speed.

This document is a little in depth but what you need is on page 12. Use the "driveshaft rpm" column and "maximum operating angle column", don't worry about the other two columns.

http://www2.dana.com/pdf/J3311-1-HVTSS.PDF

I can work out your maximum drive shaft rpm if you get for me the following.

-Max intended road speed in km/h
-Tyre size
-Diff ratio

max intended road speed - say 110km/h?
tyre size - 265/75/16, (31.6 inch), but will probably be replaced soon with 31 inch
diff ratio - 3.54

unless its an old offroad beater its not really desirable to have a centred T/C and offset diff, its a whole shitload more work but if your already ripping the drivetrain out and basterdising the truck you could also swap the axles out to something that's rear centred to match the T/C output

31" tyre= 2624rpm
31.6"tyre= 2574rpm
33" tyre= 2464rpm
35" tyre= 2323rpm

About 7° max.

You might be able to add another degree or so to this if your lucky.

Adapt the LT230 onto the Isuzu gearbox?

the gearbox, transfer case is all one unit on the isuzu

there's conversion bellhousings available to hook isuzu 4j engien to landrover transmissions. that plus 3.54 diffs would probably be pretty lush.