No transferbox output unless diff lock on

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dconnrt

Member
Posts
15
Hi everyone, This morning bringing my young lad to school, it felt and sounded as if one of the gear sticks popped out of gear but it was quickly obvious that this wasn't what happened. I found that I only had drive if I put the transfer box into diff lock and, when I did that, I could feel the front wheels pulling through the steering (I can't be sure its only front wheel drive but it didn't wind up on the rest of the journey). When its out of diff lock it makes a grinding whirring noise but neither prop turns. I took off the tunnel cover and had a look at the high/low/diff lock selector linkage but I suppose it probably can't be the problem here because it does select high and low with diff lock on.

I'm thinking that its looking like a transfer box replacement but does anyone know if there are any other common failures with the output flange or anything to look at while the transfer box is still in the vehicle ?

thanks very much!,

Derek
 
Hi,

Are you sure it is not a diff or halfshaft? where was the grinding noise coming from.


Cheers

When I don't have diff lock engaged (when I'm in diff lock off high or low ratio) neither prop moves - there is only a whirring / grinding noise that is coming from around the transfer box. I first thought when this happened was a broken half shaft or CV joint of something but then I looked under and neither prop is doing anything
 
'Well it's not the selector - all that seems fine. Now that's I've got the tunnel cover and cubby box & panel removed I can hear that the whirring/grinding noise sounds like its coming from the rear output end of the transfer box (in front of the handbrake drum). I wonder did I break the output shaft in the lt230 ?
 
When I had one die - almost like this I could just occasionally get drive for a moment after wiggling the levers.

The cause was a failed bearing that was letting the lower shaft move around, and that led to the selector fork getting mangled - effectively putting it into neutral.
 
'Well it's not the selector - all that seems fine. Now that's I've got the tunnel cover and cubby box & panel removed I can hear that the whirring/grinding noise sounds like its coming from the rear output end of the transfer box (in front of the handbrake drum). I wonder did I break the output shaft in the lt230 ?
it would be unusual if you did ,diff gears or shaft would be more common failure
 
I started it up and drove it today (with difflock enabled so front wheel drive only). I notice now that the difflock/high-low selector doesn't feel right - it feels very sloppy - it does go left and ring (difflock on to the left off to the right) and it does to up and down to low & high ratios but it doesn't seem to have the defined H pattern it used to have. What boguing mentioned above might be what's happened. Today I dumped the oil and replaced it with new oil just before I took it for a drive (I'll need to take it for a drive in order to fix it and I reckoned that if I changed the oil I might get some metal fragments out which can only help). There was a bit of hairy icon filings on the drain plug magnet but not that much.
 
I started it up and drove it today (with difflock enabled so front wheel drive only). I notice now that the difflock/high-low selector doesn't feel right - it feels very sloppy - it does go left and ring (difflock on to the left off to the right) and it does to up and down to low & high ratios but it doesn't seem to have the defined H pattern it used to have. What boguing mentioned above might be what's happened. Today I dumped the oil and replaced it with new oil just before I took it for a drive (I'll need to take it for a drive in order to fix it and I reckoned that if I changed the oil I might get some metal fragments out which can only help). There was a bit of hairy icon filings on the drain plug magnet but not that much.
hi lo lever doesnt have a h pattern lever gose side ways wherever lever is forward/back,front wheel drive would indicate failed diff center as front shaft is driven from outer diff case in diff lock
 
hi lo lever doesnt have a h pattern lever gose side ways wherever lever is forward/back,front wheel drive would indicate failed diff center as front shaft is driven from outer diff case in diff lock

Thanks V much jamesmartin. The lever is fine so and working as it always did. Looks like the next thing I need to do is think about whether to use a transfer box from a discovery I have or to buy a rebuilt one from Ashcroft transmissions...
 
If only it was - that would be great as its a much easier repair. With diff lock off and the gearbox in 1st (or any gear) there is no prop movement so the problem is the transfer box
Could I suggest even if only to convince everyone else that the diffs are ok front and rear, jack up one front wheel, turn it by hand, witness the drive shaft is turning, repeat the process for the rear, if they both turn the driveshaft attached to them there ok, try both with difflock in and out.
I had a pinion shaft break in my front diff on the RRC, it broke so cleanly that nothing was out of place and it was hard to decide if it was a broken axle, cv joint or what, the problem with yours is definitely not the same by what you describe but I still think it could be the cdl centre or one of the output shaft splines stripped, maybe drop the drive shafts out and have a look, certainly better than having to change the whole transfer box.
 
Could I suggest even if only to convince everyone else that the diffs are ok front and rear, jack up one front wheel, turn it by hand, witness the drive shaft is turning, repeat the process for the rear, if they both turn the driveshaft attached to them there ok, try both with difflock in and out.
I had a pinion shaft break in my front diff on the RRC, it broke so cleanly that nothing was out of place and it was hard to decide if it was a broken axle, cv joint or what, the problem with yours is definitely not the same by what you describe but I still think it could be the cdl centre or one of the output shaft splines stripped, maybe drop the drive shafts out and have a look, certainly better than having to change the whole transfer box.

I'm so sure that it must be a fault in the transfer box because both props don't move when I go into 1st gear and have diff lock off but I'll do this test (and although I'm 99℅ sure I hope I'm not red faced after this !).

The other thing you mention - that the output shaft splines might be stripped is worth checking before I go for a complete transfer box swap. I think it might be possible to withdraw the output shaft if I remove the rear cover ?

Derek
 
I'm so sure that it must be a fault in the transfer box because both props don't move when I go into 1st gear and have diff lock off but I'll do this test (and although I'm 99℅ sure I hope I'm not red faced after this !).

The other thing you mention - that the output shaft splines might be stripped is worth checking before I go for a complete transfer box swap. I think it might be possible to withdraw the output shaft if I remove the rear cover ?

Derek
You will need to ask @jamesmartin if you can take the shafts out of a transfer case whilst it is still in place, I've not ever done that, think cross members etc could obstruct. The splines I was talking about are the driveshaft flange splines, they can be checked by dropping out the drive shafts to expose the large nut inside each flange.
 
You will need to ask @jamesmartin if you can take the shafts out of a transfer case whilst it is still in place, I've not ever done that, think cross members etc could obstruct. The splines I was talking about are the driveshaft flange splines, they can be checked by dropping out the drive shafts to expose the large nut inside each flange.
you can remove both shafts by removing the circlip and withdrawing the out put bearings,but the gears and cross shaft would fail long before output shaft splines
 
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