Flappy whiring sound, maybe transfer box?

[Judo]

OK, my Disco (manual TDI) has started making a funny noise. I fear it's bad news...

I don't know how to describe noises... It kind of reminds me of putting a flap in a bike spokes. :cool: Not as high pitched though. I considered exhaust leak, but can't see any obvious black marks and I would describe it as a bit more metallic than the soft sound of air.

Frequency matches gearbox speed. If I let the clutch out at 60km/h in 3rd, then the same in 2nd, it is higher frequency in 2nd.
While driving, if I put my foot on the clutch it goes away.
Starts again as the clutch takes up.
Can't get it to do it by revving the engine stopped.
Can't get it to do it with transfer box in neutral and revving the engine in gear.
Sound exists in high range, diff lock and low range.

Lastly, I got up some speed, slipped the transfer box into neutral, let the clutch out in gear and I can't get it to make the sound.... Thus I'm thinking transfer box related.

Thoughts?

[Judo]

Bump....

Maybe I should have chosen a better title!

[DiscoDB]

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?

[Roverlord off road spares]

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

[CraigE]

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?

[Judo]

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.

[CraigE]

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?

[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!

[CraigE]

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

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]

Craig,

Thinking of trying some exploratory work this weekend. Maybe remove transfer box and take a look at that first. Famous last words, but it seems like I could remove and refit the transfer box without spending weeks on it. If that looks good, it's either gearbox or clutch.

Not being able to hear anything in 4th, but gears 1-3 being noisy make me think I have enough evidence to buy a new/recon R380 and just go the swap. Really the worst case is that it's something else and I still have a second good condition box I could on-sell again.

If I'm removing the gearbox, yes I would definitely do the clutch too. I see karcraft do a clutch kit for $300. Is that everything I need? I think that includes cover plate, friction plate and clutch release bearing? It's a 300TDI - do I need to replace the flywheel? (I hear that's a yes on TD5, not sure about TDI).

Unfortunately the Disco is our only car! We don't drive much though (train to work), so I can spend a few weekends on it, but months off the road becomes a long time... The problem I have every time I do major work is that I can't duck around the corner for that $2 part I need! But there are ways and I make do... I justify it to myself as even if I get a taxi to bunnings a few times a year, that will always be cheaper than owning a second car! Picking up a gearbox in a taxi might be a different story tho. :D :D

Cheers.

[CraigE]

Judo,
AFAIK know I don't think you need to replace the flywheel on a tdi just the dual mass on the TD5. If you have access to the right garage you could do a gearbox swap in a day working hard or over a weekend taking it easy. Its all the bits and pieces that take time and in the Defender pulling out the seats, floor etc to access. If you have a transmission jack and access to a hoist it will make the job so much easier and quicker. But can be done on the floor (how I did my Defender) with an engine crane.



Craig,

Thinking of trying some exploratory work this weekend. Maybe remove transfer box and take a look at that first. Famous last words, but it seems like I could remove and refit the transfer box without spending weeks on it. If that looks good, it's either gearbox or clutch.

Not being able to hear anything in 4th, but gears 1-3 being noisy make me think I have enough evidence to buy a new/recon R380 and just go the swap. Really the worst case is that it's something else and I still have a second good condition box I could on-sell again.

If I'm removing the gearbox, yes I would definitely do the clutch too. I see karcraft do a clutch kit for $300. Is that everything I need? I think that includes cover plate, friction plate and clutch release bearing? It's a 300TDI - do I need to replace the flywheel? (I hear that's a yes on TD5, not sure about TDI).

Unfortunately the Disco is our only car! We don't drive much though (train to work), so I can spend a few weekends on it, but months off the road becomes a long time... The problem I have every time I do major work is that I can't duck around the corner for that $2 part I need! But there are ways and I make do... I justify it to myself as even if I get a taxi to bunnings a few times a year, that will always be cheaper than owning a second car! Picking up a gearbox in a taxi might be a different story tho. :D :D

Cheers.

[Judo]

I have the transfer box out. Haven't taken it full apart, but everything looks OK. input gear was covered in oil and perfect condition as are the bearings and gears I can see so far.

I also have the gearbox out as I'm suspecting layshaft bearings. I removed the extension housing. My goodness that output shaft collar is tight! I was at max on a 10T hydraulic puller. :eek:

Removed the clutch also as I will replace this while it's out. Unknown history to me at 170,000kms.

Here is some pics and comments/questions.

Clutch. I have no idea if this looks OK? :confused:

https://www.aulro.com/afvb/images/imported/2015/09/366.jpg
https://www.aulro.com/afvb/images/imported/2015/09/367.jpg
https://www.aulro.com/afvb/images/imported/2015/09/368.jpg
https://www.aulro.com/afvb/images/imported/2015/09/369.jpg

Layshaft:

https://www.aulro.com/afvb/images/imported/2015/09/370.jpg
https://www.aulro.com/afvb/images/imported/2015/09/371.jpg
https://www.aulro.com/afvb/images/imported/2015/09/372.jpg

I spun the gears around but they all look good to me.

The bearing rollers are what I thought might look bad - but they look OK do you think?

Amateur question... the inner track has obviously stayed on the shaft and come out of the bearing. Is it suppose to do that? I take it that's not how it was fitted. Is it essentially a one time fit and now I have to replace it because it's been pulled apart? OR does that indicate slack in the bearing and maybe an issue? (then subsequently pulled apart easily)

Possibly the biggest point last - the layshaft nut is loose. I can spin it 2-3mm left to right. It is only restricted to 2-3mm because it's staked. Could this be the cause of my noise? The workshop manual says it should be 220Nm! So clearly I'm replacing some parts there, but it would be good to know if I've actually found my issue as I continue disassembling, etc.

Cheers.

[Judo]

Ok, never mind the bearing track question. It's suppose to be on the shaft. I read the manual. :)

[Timo110]

Justin

Did you figure this problem out. I have a flapping noise under deceleration that sounds similar to yours. Just in proces of pulling the tranny but I am not sure what to look for

Cheers

Tim

[Judo]

Firstly, you should make sure prop shaft nuts and handbrake are all in good condition and torqued up correctly. They are prime candidates for a flapping noise. If you're still sure it's gearbox related, this is what I found:

In 1 go, I rebuilt the gearbox, transfer box and installed a new clutch. The noise is gone now and been fine for a few thousand kms now. So difficult to say what it was for sure, however the gearbox input bearing was pretty bad. When I pulled the rollers off, it looked like this:

https://www.aulro.com/afvb/images/imported/2015/12/111.jpg

A few of the other gearbox bearings were discoloured. I also found the 5th gear on the layshaft had a very small amount of float due to the layshaft nut being loose. It was only held in place by the stake, but still able to rotate a few mm's.

The transfer box was generally in perfect condition. If I had of known, I would have left it. Not a mark on any bearing or gear. In retrospect it was a waste of new bearings, but I didn't know that then. I did however replace the centre diff thrust washers which were worn down.

Clutch was probably original and looked pretty worn and changed for new while it was all out.

Good luck!

[Timo110]

Thanks for the info. I have driven it with the front prop off and then the rear off with the front installed and it didnt go away. My noise is like flapping when I get off the gas

http://youtu.be/5tz_XA67Ghw

I am pulling the gear box but am only looking for the obvious as I have never had one appart before

Did yours sound the same as this? If so. With what you did, what would you check first

Cheers

Tim

[Judo]

Yep that sounds very very similar to mine!

I had never seen inside one either. One thing I learnt was there is little point in going half way if the box has many kms on it. To even inspect the gears and bearings, you're half way to a rebuild. To change bearings, you're 3/4 the way to a full rebuild, so might as well do the lot. Up to you of course.

To visually inspect all bearings you need to pull both main and extension housings apart to check all the bearings. That will leave you with 3 shafts full of gears and bearings on the bench. Inspect them. A badly damaged bearing making that noise should be obvious. Something like this:

https://www.aulro.com/afvb/images/imported/2015/12/92.jpg

Essentially if a bearing doesn't look new - it's damaged. There really isn't much in between.

Do you have a decent puller and press? You will need a big puller at exactly step 1 of taking the gearbox apart - the mainshaft collar. It is VERY tight.

[Timo110]

Justin

Thanks. You are the only one who has heard that noise!!!!

I have no puller or press. I may bring it in to a local british car rebuilder who can work on this. I am considering ashcrofts or a used box but dont have the $2k to spend on this right now. Was hoping to fix it myself

Thanks for the help

Tim

[Timo110]

Justin

Did you use the LR tool or just a regular puller. I do have access to one and have also found a used box for $300. I am going to get the used box then strip down my old tranny. I will ley you know if i find the same thing

If you have any photos of your tear down it would be great

Cheers

Tim

[Judo]

I bought this:

https://www.tradetools.com//product-range/auto-and-mechanics-tools/gear-pullers/force-hydraulic-gear-puller-set

I tried a cheap screw type puller and I couldn't it to move the mainshaft collar at all. I was stripping threads and bending things. Then I bought the above puller which was amazing.

All the photos I took are here:

Gearbox Transfer Rebuild by Justin P | Photobucket (http://s1274.photobucket.com/user/judo082/library/gearbox%20transfer%20rebuild'sort=2&page=1)

I haven't written them up anywhere tho. There are some good threads on the R380 already. Search for uninformed and Psimpson's rebuilds. There are others too, but can't remember who wrote them up.

[Timo110]

Thanks for the photbucket link. Seems it is private so I cant access

Thanks

Tim

[Judo]

Ah sorry. Try again now?

[Timo110]

Thanks that worked. I was able to get a used box that has a leak in the front input seal and apparently drive fine. I am going to give this a try before I rebuild my old one

Thanks for the details

Happy new year

Tim