Hi, we're trying to repair a 4wd gearbox on 1985 Express L300 4X4, have bought 2nd car and replaced gearbox, but now can't get 2nd and 4th. Help?!
Original gearbox, wouldn't select some gears, then only when clutch was released, till no longer working at all.
New gearbox in now, but can only get 2nd on occassion once revs are up in 1st and slam gearstick into 2nd, but 4th isn't working. 2nd gear crunches and grinds and won't go in most times.........is there an adjustment, how does the gear box work? Help

G'day Mitsuwa, I reckon I can help you out here. First up, a bit of a story.
I had been away hunting in the Flinders ranges and using 4x4 and Lo and Hi range a lot. 5 days uneventful driving. When I got onto the highway on the way home and had done about 50km's at around 110km's per hour the beast jumped out of 5th. Still had 4th so carried on to Hawker where I stopped to check things out. Found I only had 2nd and 4th. So drove all the way back to the Adelaide using 2nd and 4th. Interesting trip...
I pulled the gearbox and found that the big nut that holds the mainshaft gear cluster had come loose, this allowed the 5th gear in the baby extension housing between the gearbox and the transfer case to work it's way out of mesh and disengage itself from it's brothers, hence no 5th.
If this ever happens, DON'T TRY REVERSE!!!! If you try using reverse you get into an interlock situation in the gearbox and it jams up everything, you will be calling for a tow truck.
As I had the gear box apart, I put a bearing kit through it and replaced the synchro rings, springs, keys etc. Bearing kit I got from a bearing supplier, they got it in from Sydney. All the other stuff was available from Mitsubishi. I would never have bothered with the synchro's unless the box was already out and in bits but hey, while it was out.....
The bearing kit came with new mainshaft and counter shaft nuts which was good. I loctited them on as well as belted in the lock tab. I tensioned them up as per the specs in the manual. With the bearing kit, it has a modified thrust washer spacer thingo that takes care of the mainshaft nut coming loose so this is obviously a historic problem with these gearboxes. In the bearing kit there were instructions about this.
Having said all this, try dropping the plate off the bottom of the gearbox first. There are a bunch of linkages right at the bottom of the box so they are easy to see. They are all held together with roll pins and one drive lock pin. Don't get them mixed up, the drive lock pin only fits in one hole! If one of these pins has snapped, that may be the only thing wrong with your gearbox. It will cost you a gasket and a pin to fix. Maybe $5. If all those internal linkages look okay it will probably be time to go scrounging around inside. You will know if the mainshaft nut has come loose once you take the transfer case and the extension housing off. Mine was nearly all the way off but there was something in there that prevented it from coming all the way off, I forget what it was but I was thankful for it.
I am asuming that all your selector levers and bushings are okay, the ones from the gearbox to the gearstick?
Okay, good luck with it and let us know how you go. I am travelling O/S for the next few days but hope to log back on by about Sunday so any questions, just post them.
Oh, the whole gearbox exercise cost me around $850. Cheap when compared to a rebuild which I was quoted as starting at around $2000. Bearing kit was $330.00

Thanks Bill62 for your info, won't be able to give you an update straight away.
Hubby busy working at the moment, so once he gets a chance he will have another look at her. With a bit of luck she'll be up and running as she should!
I'm sure he's thrilled at pulling her apart again.
What's more, he's now noticed we gotta do the head now! How impressive, I'm sure he's looking forward to that one too.
Luckily I do have my sedan to drive around in, the van is our 'family' car, great for fitting kids, dog and anything else in.
Will let you know how he goes asap.
Thanks again..........

I also had this problem with an l300.As Bill said the big nut at the back had come loose,i sent it off to a gearbox shop in western sydney an had new bearings and synchros fitted,cost bout $750 but was a few years ago.After about 6 weeks later it happened again,they fixed it again but this time loktited it,i suspect they had reused the fold over washer.Second time round it was fine.I sold the van 18 months later.Obviously a common problem,however it was the only prob i had with my 85 4x4,wish i could say the same bout the 1 i have now.Good luck Shane

Hi Bill,
Yay......all done and fixed. Ended up pulling the gearbox apart and checked it all out. Syncros etc were all fine, previous owner had replaced complete 5th gear. Ended up getting the needle bearing from DVG parts and replaced that, got it all back together and hey presto, that was it!!
Oh, yeah did the big nut aswell, as on both gear boxes that was stuffed.
On the road again....just gotta get onto the head next.