R380 whining noise

I was driving back from work on Saturday night and noticed the whining noise from what I assume to be my R380 gearbox getting much louder. It is a '98 300 Tdi Wolf.
About two weeks ago I noticed a noise similar to when you reverse and old car fast, but quieter. I decided to "keep an eye on it". Fast forward to saturday and it got a hell of a lot louder, accompanied by a hesitancy to rev. I got home driving at 40, still pretty hair raising.
I got underneath it on sunday and dropped the front prop, the out put flange wobbles about 4mm up and down, is this normal?
I then tried to get the filler plug out of the gearbox but it was so tight I couldnt budge it, same story for the tranny box so it is in the garage now where they are trying to get them out.
What I want to know is what this noise is likely to be. With the front prop off and the centre diff unlocked I still get the noise at what would be about 40mph. With the diff locked I get the same. The noise goes away when I back off the accelerator or dip the clutch.
Any help would be great!

have you checked oil level and condition of oil for contamination

Sounds as though your output shaft bearing is fecked, so you would get the noise whenever the shaft is turning!

You have probably dropped most of your oil as well, so get it sorted pronto!!

Welcome, by the way ... now feck orf to the Introduce Yourself section before they start jumping on you

Posted in Intro section.

I have a local garage on the case trying to get the filler plugs out, I cant for the life of me remove them so I cannot check oil level and condition yet.
I thought it was the output bearing so I have ordered the parts but without being able to get the filler plugs out I am at a loss as to how to replace the oil in the tranny afterwards.
Any ideas?

I did notice oil spots all over the front face of the read diff and axle so it probably shat itself on saturday when the bearing went too.

You will need a 1/2" socket strong arm for the drain plug and a long-as-possible 1/2AF open ended spanner for the filler.

Whatever you do, don't take the drain plug out before the filler plug, as you wouldn't like it if there was no oil in and no way to fill it up again!

Ok. The garage loosened both for me and I topped up both boxes. Tranny was about 200ml and main box was bone dry. Still got the noise though so I am leaning towards the output bearing.
I ran up through the gears with the tranny in neutral and diff unlocked and had no noise. Did the same with tranny in high and got noise, so it is pointing towards that rather than the main box. The new bearing and seal should arrive tomorrow so I will see how I get on.

Ok. I changed the bearing and oil seal, old bearing didn't feel any different to the new one and there were a few brassy flakes on the inside face of the oil seal. I reassembled it and went for a drive and still had the same noise. On second inspection it is related to road speed, increasing in pitch as speed increases. When I coast in gear it becomes a sort of grinding noise like something is loose inside one of the boxes maybe. When I dip the clutch the noise goes away.
The 30mm but on the front output shaft was not at all tight when I removed it, which was a bit of a worry. I will have a look at the rear shaft next i guess.
Does anybody else have anynideas?

marcd said:

Ok. I changed the bearing and oil seal, old bearing didn't feel any different to the new one and there were a few brassy flakes on the inside face of the oil seal. I reassembled it and went for a drive and still had the same noise. On second inspection it is related to road speed, increasing in pitch as speed increases. When I coast in gear it becomes a sort of grinding noise like something is loose inside one of the boxes maybe. When I dip the clutch the noise goes away.
The 30mm but on the front output shaft was not at all tight when I removed it, which was a bit of a worry. I will have a look at the rear shaft next i guess.
Does anybody else have anynideas?

Click to expand...

gear box been out of oil is a worry ,and if t/box had brass flakes it would indicate diff bearings failing

marcd said:

Ok. I changed the bearing and oil seal, old bearing didn't feel any different to the new one and there were a few brassy flakes on the inside face of the oil seal. I reassembled it and went for a drive and still had the same noise. On second inspection it is related to road speed, increasing in pitch as speed increases. When I coast in gear it becomes a sort of grinding noise like something is loose inside one of the boxes maybe. When I dip the clutch the noise goes away.
The 30mm but on the front output shaft was not at all tight when I removed it, which was a bit of a worry. I will have a look at the rear shaft next i guess.
Does anybody else have any ideas?

Click to expand...

I assume the 4mm up/down play has gone? if not you need to have another look, there should only be rotational movement. If you had 'brassy flakes' it could probably do with a flush too, failing that there may be other damaged bearings if there are metallic particles floating around inside.

Yes, I assume the 4mm play was due to the nut being loose. I will flush it through after I do the rear bearing, I bought two of the front one and assume that the rear is the same size?

marcd said:

Yes, the 4mm play has gone so I assume it was due to the but being a bit loose. I will do the rear bearing this week and then flush the box. Hopefully I won't have to venture too far inside to find out what's up.

Click to expand...

if you have gear whine then you need to ,remove sump from t/box and look properly presumably your not still driving it

No, I am not still driving it! I will drop the sump and have a look inside, anything in particular that I should look for?

condition of parts,movement in bearings etc

It seems quite terminal. I got the drain plug out (I only topped it up before as I didn't have much oil) and it was covered in flakes of metal like a mohican. I drained the oil and it was full of metal, it looked like grey metallic paint and had a burnt smell. I tried getting the cover plate off the transfer box but the top two outside bolts were stuck fast and I ended up rounding one off.
Am I right in thinking a new box is probably the quickest and easiest way around this?

Oldseadog said:

You will need a 1/2" socket strong arm for the drain plug and a long-as-possible 1/2AF open ended spanner for the filler.

Whatever you do, don't take the drain plug out before the filler plug, as you wouldn't like it if there was no oil in and no way to fill it up again!

Click to expand...

I always remove the filler plug first, struggled so much with my filler plug to the gearbox this weekend!!

managed to get an extension bar on it, then a 14mm socket on that and it soon came off with the snap on gun

did have to do it from up above tho..

I just finished swapping the box for a 1.2 box from a disco. Runs a treat now and goes a bit quicker to boot.
I must say that it's a two man job and that an engine hoist would have made life a hell of a lot easier. Suffice it to say that I owe my brother lots of beer now!