What gearbox do I have?

[spy]

We have an M reg 300tdi disco with a noisey box (not too bad but rumble at idle that disapears when you press the clutch), a 200tdi type knock when you take up drive if your not gentle and a knackered 2nd gear syncro.  I have had all of the above in the past with 200tdi discos but I thought the 300tdi was supposed to be better!  Was the box from the 200 (LT77??) fitted in the early 300's?  How do I tell what box I have? 

The clutch is tired.  Its not slipping yet but bites really high and I know it wont last forever (I have been saying that for the last 15k ish!!).  If it comes to clutch time im wondering if I should stick another box in.  Its an old bus buts its solid underneath, I have done boot floor etc last year, the only thing letting it down is the gearbox... 

[Yoshi]

If reverse is below 5th then its an R380 box.

[crazymac]

As BadgersRover says, if you push the gear lever away and towards the bulkhead then its an LT77, if you pull it towards you and to the back of the vehicle then is an R380.

I would say with it being an M reg it should have the R380. There was as early issue with them around the oil supply.

[spy]

Well, its definately an r380 then.  I take it if I am looking for a second hand box I need a later one if possible?  Also how bad a job is changing the box?  Would normally take engine out to do clutch, is removing box much worse?  Have pit at work etc so not on my back... 

Anyone got a good box for sale? 

[crazymac]

Have a look round ebay etc, about £495 for a new one I think.

Changing it isn't horrendous. Least not on a 200!

The trim round the box inside has to come out, then there is a plate riveted underneath that also needs to go.

Underneath, exhaust removing to get working space, gearbox crossmember loosening, prop shafts off then undo from bellhousing. support under box and remove cross member. lower away.

Its a heavy lump with the transfer box attached, consider taking that separate 1st. 

[Budgie]

not too bad but rumble at idle that disapears when you press the clutch

That could well just be the clutch release bearing on it's way out and nothing to do with the gearbox.
Some of the early 300's didn't have the later transfer box input gear with the oil holes in it which causes the knocking on take-up but I had an M reg one that was register in March 95 and that had the later type fitted.
If you're changing the gearbox then it's worth checking that you have the later type input gear to make sure you don't get the same problem further down the line.
There's good info on the Ashcroft's site.  ;)

[spy]

Well tonight I changed the oil in the main box and transfer box while was servicing it anyway.  I added the some forte treatment to both of them.  It might be in my head but it seems less crunchy into second although its still a bit notchy (well it cant fix syncro can it..).  I think your right, I think my rattle/rumble is the clutch, the noise seems to be coming out of the drain hole on the flywheel housing!  Its definately that end anyway. 

So if we are not bothered about the clunk (you soon get used to driving to avoid it) is it likely to cause any grief?  Should I just wip the engine out and put a clutch in that way when the time comes? 

[Budgie]

If you change the clutch then you'll be able to change the release bearing at the same time. I would also get the release arm just to be on the safe side as they have a habit of waring through at their pivot point.
If you can live with the 2nd gear problem then you can fit a new transfer drive gear (£45 from Ashcroft's) to tighten up the that side of it.
You can access the gear through the cover on the rear of the transfer box, but only do this if the gearbox mainshaft isn't too far gone otherwise you're just waisting you time.  ;)

[spy]

So, how do I know if its too far gone?  How does it work?  Is the gear oversized or something?  I wouldnt do the clutch without the fork and everyone seem to think that borg and beck / AP driveline is the way forward which I have always used to be on the safe side! 

Im not too worried about pulling engine out, I just dont want to try and lug that box about unless I really have to!  It looks like a heavy swine! 

PS, thanks for the replies, mud club to the rescue as per usual! 

[Budgie]

The transfer drive gear slides onto square splines on the gearbox mainshaft.
If the ware is too much then splines will be almost gone, you know when they finally go as you loose all drive to the transfer box.
When you open the cover on the back of the transfer box then you should see the gear and the end of the mainshaft, pull the gear off the mainshaft and have a look at the condition of the spines on both.
The gear will rotate as it's removed because it's meshed with the other gears in the t-box, so make sure the wheels are chocked and have the gear & transfer boxes in neutral.  ;)
IIRC you may have to remove the rear propshaft & handbrake to get at the cover.

[Ja1983]

big wide strap over roof, block and tackle down through the hole - non of this trolley jack nonsense!

sounds like thrust bearing, not a major problem (but if it gets really loud, get it done)

and yes, they are very heavy indeed! (big lump of metal + oil + limited working area)