Thread: Flappy whiring sound, maybe transfer box?

Bump....

Maybe I should have chosen a better title!

I would suspect gearbox lay shaft bearing as you said frequency increases if you change from 3rd to 2nd (I assume at same road speed, hence higher rpm). Is it more noticeable in 2nd and 3rd, but much quieter in 4th?

I had a throw out bearing go once on the clutch and it made strange noises.

It depends. I have had similar in a Disco, RRC and Defender all R380/LT230 setups. Mine would only do it around 80kmph. I reckon it might be one of the wring harnesses getting a bit of movement and hitting against the box or body. Only did it around 80kmph and in 4th or 5th. Never did actually track down what it was.
Does it do it all the time in all gears or just intermittently?

Just went for a short drive and I think it's bad news.

Quite distinct in 1st, 2nd and 3rd. 4th is no sound or so quiet I can't hear it. Didn't get fast enough to try 5th much above idle revs, but I reckon I could just hear it.

I'm sure it's there all the time in at least 1st 2nd and 3rd - it's just hard to hear over the engine with revs up. Let the revs drop while changing gears, then let the clutch take up and it very distinctly starts as the clutch grabs.

Anything else I can do to confirm it's layshaft bearings?

I was reading some other threads on it, and sounds like the layshaft bearings can be changed without removing the gearbox. Remove transfer box, then just unbolt extension housing from gearbox. Sounds good to me? It's done 175,000 kms. Oil has always been clean and full between service intervals and still feels great to drive.

Sorry just re read your whole post. It does sound a little like a failure of some sort.
It may be possible to replace the rear bearing in situ, but I would take it out and either fit a recon unit or do a full rebuild. If it is the front bearing you will need to pull it out.
A flapping noise is unusual, normally bearings would be more of a squeal or groan.
When mine failed it was the front bearing that failed or I should say the retainer broke and the ball bearing fell out and presto no drive.
Have you dropped the oil to see if there are any filings in it?

No filing in the oil, but golden specks sitting in the bottom. I assume this is brass from the syncros and nothing serious....

I'm definitely considering another box and just swapping it. I was hoping this wasn't going to cost too much, but I think I'm out of luck if it's the gearbox!

Judo,
The brass filings are fairly normal. When mine went I ordered a box from Ashcrofts in the UK. From time of ordering including build with HD bearings was around 3 weeks, 2 weeks to build and 1 week delivery, may have actually been a bit quicker than that. If you are fairly certain it is on the way out would be the way to go. Even with paying the core charge and freight was a lot cheaper than getting a standard rebuilt R380 here. Ring or email Dave direct if you go down this path. Of course let him know we have recommended them. Very easy to deal with.
A lot will depend on your time frame if you can have it off the road for a month then I would start by removing the box and inspecting first. You may also be able to get an endoscope in through fill and drain points to have a look first. Once you have determined if the box does need a rebuild determine if you want to rebuild or just get another box. The benefit of getting the Ashcroft box is you get to keep the old one and rebuild at your leisure as a spare or for other projects. You can send yours to Ashcrofts for core exchange but you will only be about $100 or less better off as freight is around $200 one way if you actually get the same rate, then packing as well.
If you can do the swap yourself it will make it economical. If not will add some serious coin in labour.
Are you sure it is not a clutch failing? I would also do the clutch and spiggot while out, around $700 from Karcraft for clutch and new flywheel.
Cheers
Craig

Originally Posted by Judo

No filing in the oil, but golden specks sitting in the bottom. I assume this is brass from the syncros and nothing serious....

I'm definitely considering another box and just swapping it. I was hoping this wasn't going to cost too much, but I think I'm out of luck if it's the gearbox!