Td5 noise from drive train.

Hi all, in the past couple of weeks I've had a noise coming from somewhere in the drive train, gearbox or transfer case I think. It is like a chug-chug-chug, tractor sound. It has been gradually getting worse. The noise is always present but much more noticeable at lower revs under load, pretty much disappears when clutch depressed. Any ideas? I'll try to add a video with the audio of the noise.

is it just while driving or does it also do it when stationary with the clutch in?

if while driving, could be drive shafts, diff bearings, UJs?

armourermark said:

Hi all, in the past couple of weeks I've had a noise coming from somewhere in the drive train, gearbox or transfer case I think. It is like a chug-chug-chug, tractor sound. It has been gradually getting worse. The noise is always present but much more noticeable at lower revs under load, pretty much disappears when clutch depressed. Any ideas? I'll try to add a video with the audio of the noise.

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If you think it's tbox take off props and go through gears stationary if no noise might be something on props axel or diff etc... easy way to get bit of an idea though

I'm such a technophobe, so I can't add the video! The rattle or knocking is always there, it's present when stationary in neutral, but the frequency of knocking increases as the engine revs increase.
The noise pretty much completely disappears with the clutch depressed. It gets a lot worse when under load. I got under the landy today and I'm almost certain it's coming from the transfer case.
I'm thinking something like the input shaft or bearings related to it, does that sound feasible?
Cheers.

Just to clarify, I was confusing myself a bit. As the knocking is matching engine rpm as opposed to vehicle speed, this must mean it's something on the input side of the gearbox, even though the sound appears to be coming from the transfer case.
Can anybody shed any light on a possible cause?
Cheers.

If you are stationary and in neutral and it is making a noise that is rpm dependant then it wont be the transfer box as nothing is rotating in it. If pressing the clutch makes the sound disappear then you are looking at either a clutch related issue or something with the main gearbox input shaft or layshaft.

Well I eventually got the gearbox out and apart.
Not sure if it's entirely to blame for the knocking but below is a closeup of the layshaft forward bearing.

Bingo! Well found, and Kudos to Kwakerman for the diagnosis

zeaphod said:

Bingo! Well found, and Kudos to Kwakerman for the diagnosis

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are you changing the other 6 bearings too

Are they chipped teeth or a trick of the light?

That's just a trick of the light thankfully.
Yeah, all bearings and oil seals at the same time. Currently checking all clearances, end float, condition of synchros etc.

armourermark said:

That's just a trick of the light thankfully.
Yeah, all bearings and oil seals at the same time. Currently checking all clearances, end float, condition of synchros etc.

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looking at your pic id get ftc3584 x4 and ftc5018 x 2,the ones i can see are worn

What do them part numbers refer to? Is it the brass synchro rings?

armourermark said:

What do them part numbers refer to? Is it the brass synchro rings?

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yes they are the parts that you change with synchros the other 2 parts rarely wear,rev gear do teeth often get hammered and new gear is the only fix ftc5070