Do i have a knackered T-Box?

Hi All,

Vehicle is a 'fender with a 3.9v8.

As above (yes, I have searched- please help). Symptoms feel very much like a knackered UJ- LOADS of play in the drivetrain (shunting and clonking) at low throttle load (EG pottering about at 30mph), but I recently replaced both props and all UJs (2 months ago), and I've checked them all and can't find any play.
The gearbox is a recon unit with no wear to the output shaft- it's only covered 4k since I put it in.
The front Halfshafts are pretty recent, not sure about the rears- not had chance to inspect them yet.
The rear diff was fully rebuilt 25k ago (it's a Salisbury)
The transfer box was one I got for about £30, is from a V8 disco.

Vehicle was fine until a couple of weeks ago, when I was doing a lot of greenlaning (including violets lane, although that was the most extreme- the rest were all gentle), and since then clonking and shunting has been getting much worse- today it's almost undriveable.

Heading up to the LR show in a couple of weeks, so really want to have fixed by then so I can go and get my geek on

All help hugely appreciated, as always.

have you had the pto cover off? think if its oily its ok if its dry its fooked

Had a look at all four drive members? A little play in the splines = a lot of drivetrain play and clonking.

Thanks for the swift responses chaps! Haven't investigated too much yet as it's gone dark. I do know the front drive shafts and flanges are pretty good- not sure about the rears. The clonking is pretty consistent though which makes me think it's something central. If it was just the fronts or rear drive shafts it'd only clonk some of the time (please correct me if I'm being a pleb...). Not had chance to check the internals of the transfer box yet, but i am pretty sure it doesn't have a cross drilled shaft (it's from quite an early disco).

I have a 26tooth cross drilled input for sale if needed

Thanks doc, I'll bear that in mind. How tricky are they to replace?

easy, just prise the old one out

I've heard that one before! ;-)

I'll try and confirm, and check the box's serial number to make sure it'll fit. How much are you looking for it?

£30 ?

Cool. I'll try and confirm the problem and get back to you. If its not cross drilled already (I'm fairly sure on this), I'll probably take it off your hands anyway.

you need to count the teeth, some are 28 some are 26

Will do, thanks!

Is it more noticeable when cornering?

Hi bennehboy, mo it's not. It's pretty much constant wether cornering or not.

Right, had a quick look at the drive flanges before I go to work (haven't had time this morning to do anything major), and the rears seem very worn- nearside is getting on for being smooth! So i figure that's a first port of call. I'll inspect the transfer box as soon as I get a spare hour too. Thanks for the suggestions folks, I'll keep you posted.

Hi all- quick update. I've replace drive flanges and the slack has gone by 50%, which is great. Also found a little play in the props, so i've applied grease liberally, which seems to have helped too. I've inspected the Transfer box gear and can find only the tiniest amount of play (0.5mm), so i'm satisfied it's not that.

There does seem to be a lot of slack in the diffs- the front especially, so i figure i may have to spend a little money on those at some point, but i'm happy for now. Thanks all for your help.

S