gearbox problems

Hi guys,
I'm having a problem with my series 3 petrol gearbox, the problem has only just started acer replacing my dizzy!, when driving under load in 3rd/4th gears I am getting a grating noise, ujs seem to be ok, driving along with footplates out and noise seems to come from front of transfer box.
Has any on else had similar problems and what was it?, and where should I start, noise is not present when clutch is depressed neither in 1st or 2nd or when not under load.
Thanks in advance perry

Clutch release bearing possibly? Not sure, jamesmartin is the one to ask about gearbox issues

How would I test for clutch release bearing, would it not do it in all gears?

is it exactly the same in 3rd and 4th . if its just speed related ie only in higher gears it could be t/box as well ,try draining a little oil out of both boxes and tell us what you find

jamesmartin said:

is it exactly the same in 3rd and 4th . if its just speed related ie only in higher gears it could be t/box as well ,try draining a little oil out of both boxes and tell us what you find

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Not as bad in 3rd but 4th gear is really bad but only under load, i have changed gearbox oil today and transfer box was still full as only replaced 1 month aho. I've been informed you are the main man so all advise is welcomed. Perry

what was oil like any signs of debris or silver colour

jamesmartin said:

what was oil like any signs of debris or silver colour

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No silver that I could tell, no debris either

Oil wasnt emulsified was it?

samc88 said:

Oil wasnt emulsified was it?

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No, just looked like used oil, not very dark as only changed a month ago

not a lot to narrow it down then, though i would advise getting box out and looked at sooner than later

Ok I've had a blonde moment, I have not drained oil from transfer box only gear box, just waiting for rain to subside and will drain oil and let you all know my findings

Ok, I've just dropped oil out of transfer box and looks identical to the oil from main gear box, can see a little silvery sheen in both oils but no fragments at all, I have put a magnet in the used oil to see if any deposits would stick and magnet came back clean, could it be a clutch/ pressure plate problem?
It is really bad in 4th but only when under load I.e going up hill etc

from what you say suggests a worm bearing or bearings

jamesmartin said:

from what you say suggests a worm bearing or bearings

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Are these hard to do/test, is it gearbox out time? Many thanks for all help once again, I am eternally grateful perry

Yes its a gearbox out time. They arent too hard to replace, can get away with using a large socket and an extension bar as a drift if you havent got a press. Using a blow torch helps get them in and out too.

If they're worn, you'll feel it when you rotate the shaft, might feel a bit gritty

samc88 said:

Yes its a gearbox out time. They arent too hard to replace, can get away with using a large socket and an extension bar as a drift if you havent got a press. Using a blow torch helps get them in and out too.

If they're worn, you'll feel it when you rotate the shaft, might feel a bit gritty

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Excellent stuff, will be out tomorrow, will keep u all posted perry

The manuals easy enough to follow (I find the proper land rover repair operation manual to be much better than haynes)

Manual can be downloaded here, parts 4 and 5 deal with the gearbox if i remember rightly

http://www.landroverweb.com/landrover/pdf-land-rover-manuals/

Well gearbox off and all gears etc are ok, no play or any teeth missing, I did notice that the clutch release bearing wobbles quite a bit when clutch is released, is the normal?
Also does a defender clutch pressure plate fit the series gearbox?

I dont think so, mine just spins really freely, it doesnt wobble at all

samc88 said:

I dont think so, mine just spins really freely, it doesnt wobble at all

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Yes its as I thought, is its failure due to clutch pressure plate or clutch fork?