How 2 change a defender 90/110 transfer box.

Right folks, I’ve just had a w’end doing this for the first time and made a few mistakes but got there in the end, so, I thought I would put together a help guide to any of you also facing this for the first time.

I have included as many pic’s as I can, and there may well be things that the more experienced out there would suggest as not done the best way, but that’s fine.
This is purely from a non- experienced account, for other novices to get their teeth into.

To start with:
I would suggest that you start inside the cab of your 90 or 110 by removing the middle seat or cubby box.
Then remove your gear stick nobs, gaiter and foam insert.


If you are lucky enough to have the sound proofing and/ or carpet covers. Remove these also.
Your gaiter is fixed onto the gear system housing which in turn you can see is held by a series of screws and you may also have to remove the floor panels if, like mine, they have been fixed down on top of this housings lower rim.


Now that all this is apart you will clearly see the linkages, the front prop shaft joining the transfer box and also back towards the rear prop shaft, handbrake drum and linkages etc so you can get to everything at all angles which is very useful so worth the time to get there.

Now it’s time to remove the linkages to free the transfer box from gear box.
My finger is pointing at the linkages to which I refer.


Now, I made the mistake of taking apart these linkages at the very top where I am pointing but you DON’T need to do this.

Both of these linkages connect to the transfer box at the lower end.
The following picture shows the lower end of the outer linkage disconnected as well as the mistake of upper end disconnected. The lower end is the 10mm nut you see in bottom of pic. Undo this and the metal link plate simply lifts away and shows folded back in this pic.


Look again to the top where the pic shows another link behind and under the link arm you have just disconnected. This link goes back through the gap in the seat tray panel and connects with a pin and split pin, as well as a double nut linkage as shown in this pic:


Now the mistake I made here was that because I had disconnected this at the other top end, when I put the box back on this link arm wasn’t considered and ended up flipped over on the lower linkage and was located on the middle seat side of the seat housing gap it should be going through. I therefore had to then undo these lower linkages to remove arm all together and position it correctly before joining all these links up again.
If I were you, I would disconnect this arm from the bottom linkage and leave it attached to the top one. The simplest way to do this is via the two nuts. Slacken off and remove or remove the clip you can see on the pin link at very end. I honestly can’t remember if that pin is removable or not due the room on one side of it. You will be able to see when you look down there though.
If you choose to disengage this arm at the TOP linkage, that’s fine… but.. MAKE SURE ITS FACING THOUGH THE GAP WHEN YOU PUT BOX BACK ON.

At this point you have done everything you need to from inside the cab, BUT , if you have removed the floor plate on drivers side, take advantage and undo the upper prop shaft bolts as its looking right at you. These are 9/16th spanners. 1 ring and one open ended or a prop shaft removal socket.

Now time to get on your back.

Get underneath and start by removing both front and rear prop shafts. Slacken all nuts on both with the handbrake on. When release the handbrake (HAVING CHOKED THE WHEELS) you will get rotation to get to the bolts in turn a little easier. If you need to, simply put handbrake back on and it will lock in position to undo each further.

Now lighten the load by removing the handbrake drum which is simply a case keeping handbrake on and undoing the two large retaining screws that are shown on the next pic.


Then release the handbrake and the drum should turn and with a bit of jigging it will pull off the shoes inside. A light tap with a rubber hammer might help also.

With the drum removed you will see 4 retaining bolts inside on the back plate between the shoes. Ease these off but don’t remove yet.

Now look behind the back plate and you will see the link where the handbrake cable joins in through the back plate of the drum to the shoes. See pic:


You need to undo this by removing the split pin and pushing the main pin out. Handbrake is now separate. Now go back to the inside of the back plate and remove the 4 bolts you have already slackened off, the whole back plate will now remove with shoes in place and undisturbed. DO NOT undo the large centre nut that you can see. Simply slip the whole plate over this housing.

You now have a clear view at the speedo linkage where it goes into the transfer box. Remove the small nut that holds the fork clip in place. The fork clip will fall away and the speedo cable will simply pull out. See pic:


At this point go back into the cab and remove the handbrake, not by the top linkages which are a pain to do, but by simply removing the gaiter from the handbrake itself and then the linkage underneath is a split pin through a metal linkage pin. Remove these pins to disengage cable but then you need to undo the gear lever mount itself by getting a spanner behind it through the middle seat aperture, and another on the bolt heads on the handle side. Once you have done this handle and its base will come away and the cable will pull though the bodywork in under the landy.
Doing this also makes it easier to see the linkages from the driver’s side when it comes to putting everything back together.
Ignore the handbrake frame housing if you have this. It is easier to remove and simply swap to the other box, if needed, once the box is off.

Right. Back underneath.

You now have the handbrake disengaged lever side and box side, the handbrake drum removed to lighten the weight, the speedo cable disengaged and tucked up out of the way, the 2 linkages from the transfer box to the gear levers removed and also both prop shafts removed from front and back.
I think there are also a couple of wires to disconnect. Just look all around and remove anything left that will adjoin the transfer box if you see it.

Now, the main bolts that hold the transfer box to the gear box. You will see these quite clearly around the top, but, the lower ones are tucked away a little. 1 is lower side slightly left and on the front facing side. The other is best seen by looking behind where the linkage arm from the gearstick comes through the gap in the seat box housing.. just tucked in there. I used and extension socket arm to reach it. You can refer to your replacement box to see clearly where these are located.

The box is now held up by the transfer box chassis mount which is the one with a big round rubber collar sat inside a bracket joined to the driver’s side of the chassis. Undo the single nut underneath the bracket, then get your trolley jack and jack it up to the underside of the box to take a bit of weight. Then undo the 3 nuts that secure the mounting bracket to the chassis so that it will completely drop away from the transfer box. Your jack is doing its job instead. If you need to you can jack the box up to free it from the bracket if its snagging in any way.

Now.. time to start pulling the transfer box away from the gear box.

THIS IS HEAVY and if, like me, you are not feeling strong, be cautious and have a trolley jack lowered slightly away from the box so you can still physically move it, but close enough so you can rest it down onto it as it comes away and you need a rest. It also pays to have a helper ready who is capable of operating this jack.

You should be able to physically get a hold of the box and put some muscle behind it to jiggle it and break it away from the gear box. It won’t fall down on you immediately as it is held on the gear shaft that joins through the middle. I got it to start separating then used a crow bar to prize it slowly further away.
At this point as you separate further apart, to approximately 5 inches, it will start to tip and come away from the splines with the full weight. This is where that trolley jack is very useful, or, you simply have to take all the weight and get ready to lower it down to the floor. I prefer the jack option.

Make sure the jack is well positioned to balance the transfer box on it. Force the box free and rest it on the jack but support it from tipping side to side with your own hands and strength and get you jack operator to slowly lower it down as far as you can, then lower to one side off the jack onto the floor. I actually did this onto a bit of old carpet which I could then grab a hold of and pull out from under the landy nice and smoothly rather than lifting it.

ITS OFF. WHIPPEEEEEEEEEE.

Now you have your old and new transfer box next to each other and you can see how the handbrake bracket can be undone and swapped over easily if you need to.

The rest is now easy as its simply a reverse of what you have just done.

When getting the new box up in position, use your jack again to lift it in position operated by your buddy or mrs in a low cut top like I did.. it adds a bit off fun to things. Get your helper to pump the jack and raise the box slowly whilst you support and angle it. I had my jack sat on a big sheet of shinny vinyl so I could jack up into position and physically push the box onto the splines, when lined up, by dragging the whole jack on the smooth vinyl an inch at time whilst my mrs moved back end of jack in same manor. It takes a bit of getting onto the splines and a lot of grunting and, in my case, swearing, but once it engages it will simply slide on so you can remove the jack and physically force it back down the shaft to marry up with the gear box.

The rest you know as you disconnected it all so do all the same in reverse to complete the job.

Once completed and everything is checked and double checked to be sure, there is just one thing left to do which is renew the transfer box oil. Use ep90 gl4 which can also be used on the axle diffs but not in the gearbox itself. For the gearbox use MTF94. I’m sure someone else can advise of any other types you could use.

The drain plugs are quite visible at the bottom of transfer box and diffs. The top up plugs are about 3-4 inches above and if you undo the top ones first you will be sure that you can get more oil in if you drain off and air will get in when you drain off enabling a quicker drain with no vacuum building up inside. Then undo the drain plug and let her drain off into a bowl.

To top up you simply fill through the top plug until the oil starts to drain out of this plug. That’s what sets your oil level. Approx 2.8 ltrs so make sure you get a 5ltr tub. Use the rest on one of your axle diffs using the same principle.

Well, that’s basically it folks. I just hope your replacement box doesn’t whine and have bad bearings in it like mine has once I took it for a test drive.

I HAVE TO DO THE WHOLE BLEEDIN THING AGAIN.. but probably in half the time lol.

GOOD LUCK… HOPE THIS HELPED.

HAWKY666.
:beer2:

 

Don't suppose you still have the pictures from this as it seems photobucket isn't showing them anymore?

 

Agreed, that would be great.