A quick call for ideas please.
The Landy garage has just called. They have fitted the new transfer box and they have reported being unable to select high/low range and a horrible grinding noise from the transfer box when run.
The transfer box is about 10 years old and completely unused. I had the case apart to change the epicyclic gears from manual to auto. Nothing was else was disturbed and it went back together easily enough. It turned over by hand when reassembled. Can't think what could cause this. Ideas please gents?
The garage is going to have another look at it they said. Hope they put fluid in it.

Sounds like it has jammed so it is not quite in high or low, but with the teeth just touching and causing the grinding noise. They should be able to take the motor off and turn the triangular spindle one way or the other. It turns though about 300 degrees to go from high fully engaged to low fully engaged.

Thanks Richard. That sounds plausible. I have relayed your comments to the workshop foreman who is supervising the job.
Hope it is as simple as that.

The garage finally came back to me (Landranger Services, Middlewich). Car had gone to the back of the queue because of a backlog of jobs.
They tried the suggestions, but they couldn't solve the problem and have put the old transfer box back in.
Recons there is a problem with the new box. He says the spindle was free and moved OK. Old box is fine.
Including changing the engine mounts, 11 hours labour @ £68 an hour.
£878 all in and I am back to square one. Nothing to show for it. F**king disaster.

Sounds like you'll be pulling that transfer box apart then. The overhaul manual is pretty comprehensive so you should be able to work out what the problem with it is.

I am not convinced that there is anything wrong with it but I will investigate.

I am reluctant to let that particular garage touch it again, even though the foreman is adamant they spent 11 hours on it.

2 hours to swap the box the first time round, 1 hour to change the engine mounts, 2 hours to swap the old box back. 5 hours so far.
Missing 6 hours pissing about.

Hang on a minute? If it was a problem with the transfer box it would only make a noise when the gearbox is in gear as that is the only time it is turning. If it makes a noise with the gearbox in neutral, then it isn't the transfer box. Or are they saying that when they put it into gear (so the gearbox output shaft is turning) the car doesn't move but it makes a grinding noise? That would suggest the gearbox output/transfer box input isn't engaged properly.

Could it be the transfer neutral setting ? Had a defender strip teeth between gearbox/transfer box

what was the original reason for the swap i missed that ?

I have made arrangements to pick the car up on Thursday, so will grill the garage then. At the moment I don't have all the details about it.

mad-as: I wish to keep the car in as good condition as I can and I have been ticking jobs off during the lockdown. I have just done the headlining for example. Anyway long story but I aquired a brand new transfer box on Ebay about 10 years ago. The seller was from Bridgend in South Wales where a BorgWarner factory shut down. I didn't ask questions. It has been on the floor under my workbench since then. It was for a manual box but I aquired a set of epicyclic gears for an auto box and changed them over. Reason for changing? Because I had it and the old box although it works OK has done 165k miles. I figured the chain and viscous coupling must be on their last legs. I thought a quick job to swap them over.

Well, I am £900 poorer. I picked the car up today with the old transfer box back in. Back to square one.
I did however get new engine mounts and a new gearbox oil seal.
I spoke at length to the workshop foreman and the mechanic who actually did the job.

Facts: with the new transfer box fitted, there were no problems running the car in neutral. It was only a problem when it was put into drive to move the car. There was a horrible crunching sound. He said he didn't make too many attempts but there might have been damage caused.
The car was pulled out of the workshop to park up outside to get on with other jobs. There were no problems towing it which proves the chain and drive side is OK. The high/low motor also works OK.
The mechanic reckons it is the viscous unit (originally new and unused). Because of laying up for 10 years+, the oil can settle in one place?? possibly locking it up?? Can you believe that??
I had the viscous unit out to have a look at it when I previously had the box on the bench. I don't think I could have assembled it wrongly.

The next stage, I think I will try fitting the new viscous coupling to my old box in the car to test it. It is fairly easy to do.
I need to get geared up to changing the transfer box myself. Richard: you mentioned using a scissor lift was preferable. Any recommendations?

What is more disconcerting is a comment by the workshop foreman that Landrover parts that have been rejected for quality control problems and should then be scrapped, find there way back onto the market. As an example he said about Freelander diff units that were destined to be crushed then are sold off as new. The scrap yard is contracted to crush the parts but if there is money to be made.
His garage had been offered them in the past. I don't think that is the case with the transfer box though.

If it can be towed without making any noise then it won't be the viscous coupling as that is between the two outputs. As you say, the chain will also be turning when towed so again that would rule that out. That leaves the input side of things. So you would be looking at the input shaft where it connects to the output of the gearbox, but as you have changed the epicyclic gears to those for an auto, then the splines on that which engage with the gearbox output shaft should be correct. That really only leaves the high/low gear or the epicyclic gear set you fitted was knackered. When putting it together the manual does say to put it into low ratio so everything lines up. I suppose it's possible that the selector fork came out of engagement with the cam groove that makes it move from one ratio to the other, so it isn't moving the sliding gear. With the motor off, you should be able to turn the shaft over something like 300 degrees (almost a full turn) and hear the gear engaging at each end of the travel. If the shaft just turns freely, or won't turn over the full range, it isn't doing anything.

When we took my TC off we used a scissor lift as there was one available but it isn't ideal due to the angle the TC sits at. The first time I took one off it needed two of us under the car to wiggle and wobble it about until it lined up. The second time, before taking it off I made up a bracket that fitted onto my trolley jack so I could sit the TC on it and hold it at the correct angle. The theory being that the jack would take the weight and it could be moved back and forth to remove it and put it back. When putting it back, I used a couple of very long M10 bolts in the more accessible fixing holes so it would slide back into place on those too. With those bolts and the input shaft it all lined up nicely. I didn't remove the exhaust Y piece (which you may not have on a diesel) that runs across the car under the TC or the crossmember. I also didn't disconnect the gearchange cable that the book tells you to do as with an assortment of socket extensions and a knuckle joint, I was able to get to all the bolts that hold it to the gearbox. A couple of the bolts are a pain to get to but it can be done. As they've been out recently you shouldn't have too much of a problem.