Thread: Series III Transfer Box problem

You could try removing the dust/mud covers in the front of the box & free up the shaft which may be rusted in place with disuse. Plenty of CRC etc & a bloody big hammer & moving the hi/lo lever back & forth, should sort it, if it's that.

The gears in the gearbox and transfer case need to be turned to line the teeth up so they will mesh together, so it could be that you will need to repair the clutch and have the engine running to achieve this. If this does not work it may be that the exsternal linkages have rusted and may need to sprayed with penetrating oil and loosened. I hope this info is of some use. from John

Hi DiscoDave
Is it possible the transmission is "wound up".
For this to have happened it would have needed to be driven in 4WD for some time on hard or reasonably hard ground.
It is possible for the yellow hi range knob to be engaged even though it has popped back up.
To un wind the transmission you will need to reverse for a short distance in 4WD,it doesnt mean its jamed just under mechanical load.If the vehicle isnt moveable you could try putting it on blocks and turning the wheels.
Have you got free wheeling hubs??? if so and they are locked??? a telltale sign that the transmission is wound up is one hub wont unlock.
The Series transfercase is one of the toughest made and although they can get quite noisy they dont suffer from many many breakages.
Remove the transmission tunnel and floor pieces,it will make it easier to spot trouble with the linkages.You may even have a stick jammed up there.
Best of luck
Andrew

It,s been a while but here goes. A common problem can be rust on the end of selector shaft. this is located on the front of the tranfer above the output for the front drive shaft. you will find a weid looking cap retained by bolts. If you can take the cap off this will give you an idea if this is the problem. Short of that it may well be a broken or loose selector fork.

really sounds like a strip an inspect. There may be someone on this forum who may have more advice. like I said it,s been a while since I rebuilt one of these.

glen

Originally Posted by DiscoDave

I'm trying to get my semi-abandoned 1976 SeriesIII running again (without much success so-far) and one of its problems was a sudden and seemingly permanent inability to select high or low ratio i.e. the red lever won't move. The clutch hydraulics had a problem which I've isolated to a master cylinder leak but I don't know if that would be the cause of it. Filling up the clutch reservoir and pumping the pedal gives some 'feeling' in the clutch for a while but makes no difference re hi/low selection. The gearshift works fine - even without a clutch I can select two or three gears. The engine is not running at present but when it ran it made no difference to the problem.

Does anyone have an idea what the problem might be? Or can you give me a hint what to look for - I have no experience inside a gearbox at all.

As others have said.

1. Check it is not wound up in four wheel drive - jack up one front wheel and make sure the wheel is free to turn. If that was the problem, the red lever will now be free. Even if the teeth don't line up you should be able to get neutral.

2. Remove RH floor - you probably want this out anyway to get at the slave cylinder - for that matter remove both floors and the transmission tunnel, you probably want to clean up and inspect under there anyway.

3. If the lever will not move, the problem is almost certainly that the selector shafts are seized due to rust outside the transfer case extension. There are three of these, one with the red lever operating on it, the other two hidden by a pressed metal cover that covers the bits that stick out the front of the extension housing. The cover may be missing, but if not remove it (three bolts) and clean and wire brush the shafts. This plus a spot of oil should free them.

4. This step 3 will almost certainly fix the problem, but if not I think your next step is to get a manual. Pulling the extension housing off and repairing it, in the unlikely case it is necessary, can be done with the box in the vehicle, and is fairly easy, although I must stress again with LandyAndy that it is very unlikely there is an internal problem. If there was, it is more likely to be something like four wheel drive will not disengage due to a broken pin or spring rather than the lever will not move.

John

Thanks very much for your prompt and excellent advice everyone. That's given me a lot to go on.

I don't think it would be a rust problem on the selector shaft because the seizure happened before it was "abandoned" and was quite sudden i.e. one day it worked fine, the next day locked solid. But with intervening neglect I guess I need to be aware it may have rusted in the meantime.

Originally Posted by LandyAndy

Hi DiscoDave
Is it possible the transmission is "wound up".
For this to have happened it would have needed to be driven in 4WD for some time on hard or reasonably hard ground.
It is possible for the yellow hi range knob to be engaged even though it has popped back up.
To un wind the transmission you will need to reverse for a short distance in 4WD,it doesnt mean its jamed just under mechanical load.If the vehicle isnt moveable you could try putting it on blocks and turning the wheels.
Have you got free wheeling hubs??? if so and they are locked??? a telltale sign that the transmission is wound up is one hub wont unlock.

The answer is 'yes' to all those questions - all the driving I've done with it is in 4WD primarily on sandstone. I jacked up the passenger side of the vehicle to get at the clutch slave cylinder and noticed I cannot unlock the fw hub and cannot rotate the wheel (by hand anyway).
It would be great if the problem were that simple.

Well - after releasing the handbrake (oops!) I can rotate the front wheel and now the hub can be unlocked. Rotating the front wheel, with the hub locked, also rotates the rear wheel even though the yellow lever is 'up'. Is that normal? None of this made any difference to the red lever which is firmly jammed in neutral so I'm off to take out some floor panels.

Dave.

You are stuck in four wheel drive - almost certainly stuck selector rods, and the stuck red lever emphasises the diagnosis. There is a slight chance it is inside the transfer case extension, but not much. If it was only stuck in four wheel drive, it could be that the pivot for the lever under the yellow knob has fallen out, but together with the stuck red lever, this really does suggest the selector rods are stuck.
John

Well, after taking out the floor (which only required drilling out 2 seized bolts) and the cover over the transmission tunnel (thank you for that hint JDNSW) I discovered what appeared to be a large lump of tar with driveshafts and gearshifts sticking out of it. Application of heavy-duty degreaser and a brush for a while finally revealed the transfer case.
Removal of the tunnel cover required removing the yellow knob and associated spring and after application of lubricant the "selector rod" kind of collapsed and lo and behold I can move the transfer gear lever!

Now it's a little hard to simulate what's going on without the cover and the spring present but it seems the selector rod drops (upwards) into a position that prevents movement of the transfer lever out of the high ratio position and possibly the neutral position. In other words to change from high ratio to low ratio (or even high ratio to neutral) would require two hands, one to hold down the selector rod and the other to move the transfer lever. I'm sure it wasn't like that before.

Can someone tell me how it's supposed to work?