Gearbox :(

I wouldn't worry too much. If you want to be sure, take the "PTO" cover off the back of the transfer box and have a look in there. What you are looking for is where the mainshaft from the main gearbox enters the splined part of the transfer box gear. There were issues with lubrication on these splines leading to them being worn thin. The clonk when you take up drive would be die to movement in here. It's usually Aa gungy, metally mess in there if it's worn.

However, it's not all doom and gloom, its more that likely worn bushes or play in the diff or even worn propshaft splines, a little bit of wear in each of theses components often adds up to a big clonk.

My 90 did it too but I never had any problems with it, my Range Rover does the same too, and it's now got 138000 miles on it.

Dave

Its got a new prop on the front, and the rear one is in good nick.

The clonk is still there in low and high, diff locked and not.

I dont want it to explode on me! If it does break whats likely to happen. Cant select gears?

Hi Mark, just to let you know I had a similar clonk taking up drive which turned out to be a worn A-frame ball joint. Very quick replacement job and no more clonking. Some excellent information here :-

Dave.

Yes, you'll just loose drive. The gears will still be selecting as normal it's just that you will not be able to transmit drive. Like the transfer box slipping into neutral. Taking the cover off and looking will take about 20mins so well worth a look

If the clonk indicates wear on the mainshaft splines (and this is a R380 problem not an LT77 one) the failure will simply result in no drive in any gear. But seriously, I would look for where the free play is - you will be able to feel it at the gearbox regardless of where it is. If you chock the vehicle, then jack up one back wheel and have someone rock the wheel back and forth while you look for where the movement is (handbrake off) you should be able to track it down. My guess is it will be an accumulation of small bits of slack. Some of the places likely to have a lot of slack are the A-frame ball joint, lower link bushes, splines on the drive flanges of the rear wheels, side play in the rear diff centre, side play in the centre diff (in both cases wear on the thrust washers on the planet and side gears). None of these are likely to indicate imminent failure, but any play in U-joints on either prop shaft should be rectified ASAP, and if there is excess play in the front axle, suspect a CV joint which should also be rectified at an early date. Similarly, if you find a lot of play anywhere in the suspension bushes or ball joint, these should be fixed, not because they presage some disastrous failure, but because they affect handling. Hope this helps, JD

I've heard rumour that if you catch them early enough you can get away with just putting the transfer gear in this can be done without gearbox removal (apparantly) so a much easier job! Saying that there is no substitute for doing it properly.

There is a couple of outfits near me that charge around £500 to remove overhaul refit, hope this helps

Icky

The first five years were probably clunk free in mine. The next eighteen have had an increasing clunk though and I have anticipated a failure for all that time. It hasn't happened yet. However yours could fail in the next mile or so ;-) Don't worry about it. If it fails, it fails. If it doesn't, then great news. In this case, if it ain't broke then don't fix it. This has stood me well for eighteen years after all.

Huw

On or around Fri, 01 Sep 2006 21:23:40 +1000, JD enlightened us thusly:

I think you mean "and". I rather thought that later R380s were more immune. all the LT77s suffer, unless they've been worked on.

it'll carry on for some time if you treat it carefully, but eventually, the splines disappear altogether.

recon box and a cross-drilled T-box gear. cost me about 600 notes for a recon box for my disco, but they are available cheaper, but possibly not better - it was a nice smooth one.

fitting depends on who does it. anything from about 100 to 300 notes, as a guess. LR book time is about 6 hours, but I don't know anyone who can do it that quick.

On or around Fri, 01 Sep 2006 12:54:45 GMT, "icky" enlightened us thusly:

once it's really clonky, it's too late. Mine had almost no splines left on either the gear or the shaft.

If you get it *before* it's worn, then you can fix with a cross-drilled gear.

Mines a bit clonky I've had it in bits and it didn't worry me I could hardly tell it was worn. Fitted a steve parker oil dribbler under the end plate that should stop it going further (but I've got a spare g/box squirrled away just in case). It seems as soon as theres any play at all it starts to clunk, but I've got smooth gearchanges sussed.

-- Jon

On or around Mon, 4 Sep 2006 18:47:53 +0100, "jOn" enlightened us thusly:

Mine was clonky when I bought it and did about 30K miles before I actually did anything with it. There's clonks and clonks, though - some are built-in, and I've yet to see *any* LR that isn't a bit clonky, there's just too many gears all with a bit of lash in 'em, plus all the prop joints, diffs and CV joints and hub splines...

Amplifying that a little.... Don't assume that because you have a clonk that you have a problem. Most importantly don't assume that if a particular unit has free play that it is the source of the problem. As previously mentioned the ball joint over the rear axle can be a good clonk generator as are the propshaft UJs but both are very easily diagnosed.

Most of the the clonking can be controlled with delicate footwork.