Thread: Isuzu 6bd1 into Jeep

Digging up the dead. Does anyone know what happened to this one?

After realising that the sump and oil pickup can't simply be altered, lots changed. I have now cut a rather large hole into the firewall and moved the engine back to allow the sump to clear the front diff. The front diff pumpkin is on the drivers side. Fortunately there's lots of room under the dash to allow the firewall to go back about 15-20cm and aside from an easy mod to the wipers I see no problem with this option. The engine mounts are finished but not the gearbox mounts.
Isuzu t-cases are worth big bucks, so a non Isuzu divorced case seems the best option. What model Landys did the LT230 t-case come out in? Is it a divorced t-case or is that something you do to them?
It seems the divorced Nissan t-cases are from the 720's and that makes me assume they would be a bit light weight. I'm told the MQ/GQ t-case are up too the job. Can they be divorced?
At this stage I'm open to any suggestions regarding the t-case.
The long break in the projects progress is because we've been road tripping and enjoying a few festivals.

Originally Posted by Isuzu Jeep

What model Landys did the LT230 t-case come out in? Is it a divorced t-case or is that something you do to them?

Many...basically any manual 5 speed LR (110, Deefer, disco, RR*..well not all the RRs - some have a borg warner) and many autos as well (but i've no idea which ones.. not a auto person).

There are a few different types, but they are all more or less the same. For a little while the Disco ones didn't have a CDL.

Check the Ratios: Defender - 1.4:1, Disco, RRC - 1.2:1, Isuzu 110 - 1:1

For extra strength slip in a cross drilled input gear (better lubrication) and a one piece center diff pin (stronger) if you are rebuilding one to go in.

I recently got a low km job from a RRC recently for $250 to drop in my Isuzu / R380 conversion (from the markets on this site).

There is a chap on the forum who makes the adapter to fit the LT230 to the isuzu MSA g/box - search around if you are interested.

The LT230 is not a divorced case, but can be (so I am lead to believe) used in such a way.

LT230's were/are fitted to many rangies, discovery 1 and 2 (don't know about 3's) and defenders from early 80's, but somewhere around early 90's rangies changed to BorgWarner viscous transfer. Came with all 5 speed manual boxes or autos in discos and some rangies.

The easiest way to divorce them IMHO would be to modify a spud shaft from the ZF auto (as used in discos).

The spud shaft has a male spline on one end that fits into the LT230 input gear (and a centre bolt to retain it).

The other end is larger diameter and has a female spline that goes onto the output shaft of the ZF auto. This end protrudes from the front of the LT230 - I would weld (needs appropriate pre-heat and electrode/filler wire) a flange onto it so that a short driveshaft could couple the gearbox and T/case.

1st pic shows a divorced LT230 in a Land Rover with Cummins engine and a USA gearbox. 2nd pic shows early (left) and late spud shafts for the ZF auto. The longer splines on later shaft are needed for the fix to cure premature spline wear. You can see the retaining bolt in the top of the left shaft.

Originally Posted by isuzurover

I have 33's with a 4BD1, 3.54 diffs and overdrive 5th gear. That setup is great on the highway.

33's, 4BD1, 1:1 top gear and 3.54 diffs are also OK on the highway.

However you will have 33's, lower diff ratios, and a lower revving engine...

But by now you should be driving it - so you can tell us what it is like on the road???

Well its still in the shed, funny how these projects are easy to start.
So if my tallest compatable ratio with both diffs is 3.73 and I get an overdrive gearbox and run 33' tires, I should get reasonably low revs, right? Would a TC with a further overdrive be overkill? Anyone have an opinion on the best choice out of these LT230's for my application? Defender - 1.4:1, Disco, RRC - 1.2:1, Isuzu 110 - 1:1
Of course I could still change to a dana60 rear diff to obtain 3.54, though I'd rather not add another job to the list.
I've found a chap who has a selection of Isuzu 6speeds for around $1400, he's told me to split my engine and gbox to measure and count splines on the shaft, apparently there's a few different sorts.
I've been gifted a GU G/box & TC so it's time to decide if I create a GU divorced case or LT230 divorced case. They are both likely to be up to the job but perhaps the extra gearing available from the LT230 is desirable.
And what about the Defender - 1.4:1 TC and keep my non O/Drive 5 speed?
Some guidance from da guru's please

Different gearbox input splines just mean a different clutch plate is needed. Not a show stopper.

Well I bought a second hand 6 speed with overdrive for $1000. Now I just need to decide if I use the GQ transfer I already own or buy a LT230. Both will need divorcing or adapting.

Well I want a pto and the Gq TC doesn't have one so does anyone have a lt230 for sale?
Does a 1.4:1 TC give a lower engine rev than a 1:1?