Outer Limits 4x4 Board

ok dumbdance is really stumped on this one.

vehicle: 1996 multivalve turbo, 200,000km, part time transfer case (120,000km on transfer), 5" lift, 315/75 tyres, air lockers f/r

my 80 has a persistent driveline whine, audible from about 60km/h and annoying from about 80 and up. It sounded so much like the diff that I swapped it out with another diff, and the noise was still there, and I still thought it was the diff, so the diff has been rebuilt twice now with different gears each time. The noise is on drive/power but not there on overdrive/coast. it is constant with road speed. It's not tyre noise - it goes away when you lift your foot off the go pedal. I've replace wheel bearings and the diff is as new. it certainly doesn't sound like tailshaft vibes - it's way too high frequency, and it doesn't sound like the transfer case, but of course it could be. any other suggestions? my next plan of attack is to drop the suspension down and take it for a drive in front wheel drive (at the moment those sorts of speeds cause front tailshaft vibes), to isolate it to the rear axle or transfer case.

it's really annoying - it's an excellent vehicle otherwise but at the moment I just hate driving it because of the noise so 80 owners have to had problems like this and what is the solution?

cheers

DD

Gday Brian
Id say, the next possibility would be tailshaft unis...especially if they now have to move past a previous wear spot because of the lift....or your rear flange is not on the same plane as the transfer output.
Maybe drop the old rear springs back in and go for a drive...if it is still there, its not that........i have a pair of longer thick walled lower arms if you want to try them.
If all ok, then id remove the transfer bung and see what has collected on it ...
Hope its unis...

I was just talking my mate last week about doing a part time conversion on my new 80 (just bought a 97 multivalve TD auto ) and was told that the part time transfere will make a whine.....didn't get too much an explanation just "they all do".

Did the whine start about the same time as the part time was installed? Just a thought.

Alec

Surfin Alec wrote:I was just talking my mate last week about doing a part time conversion on my new 80 (just bought a 97 multivalve TD auto ) and was told that the part time transfere will make a whine.....didn't get too much an explanation just "they all do".

Did the whine start about the same time as the part time was installed? Just a thought.

Alec

Yeah I've heard the same .. normally 80 series don't whine at all unless they are fcuked. Either that or your transfer is faulty/out of oil or something like that.

Surfin Alec wrote: Did the whine start about the same time as the part time was installed? Just a thought.

Alec

it's a possibility... but the transfer came out of my previous 80 - a DX with around 100,000km, and it made no noise. I might drop the oils this afternoon and have a look - that's easy - then perhaps investigate the tailshaft unis (but it really sounds too high frequency for tailshaft unis I think)

thanks for replies so far.

Sounds like gear contact whine if it's not the rear diff, my guess would be the transfer

Tiny hole in the exhaust somewhere letting out turbo whistle?

Just thinking outside ths square...

What sort of bearings support 5th gear? i remember reading in 4WDM about an overdrive kit available for TD5 discos that replaced the bearings on 5th gear which needle bearings IIRC which reduced whine.

One other thing to try....swap the tyres around.
My part timer doesnt whine either, maybe the constants being converted do, but Brian and mine are factory dx.
Andrew

80 has a persistent driveline whine, audible from about 60km/h and annoying from about 80 and up. It sounded so much like the diff that I swapped it out with another diff, and the noise was still there, and I still thought it was the diff, so the diff has been rebuilt twice now with different gears each time. The noise is on drive/power but not there on overdrive/coast. it is constant with road speed. It's not tyre noise - it goes away when you lift your foot off the go pedal. I've replace wheel bearings and the diff is as new. it certainly doesn't sound like tailshaft vibes - it's way too high frequency, and it doesn't sound like the transfer case, but of course it could be. any other suggestions? my next plan of attack is to drop the suspension down and take it for a drive in front wheel drive (at the moment those sorts of speeds cause front tailshaft vibes), to isolate it to the rear axle or transfer case.

Substitute "80" for "60" and you've got exactly the same problem as i do in mine - high pitched whining when on the pedal, no noise when coasting or off it, constant with road speed, no play in uni's, rebuilt diff and all wheel bearings, still there... be interested to see whatpeople say

Update:

this weekend I threw some time and money at it. I have tried an alternative transfer case and the noise is identical with both. I dropped it back onto standard springs and in rear wheel drive the noise was still there, but slightly less - so that got me thinking tailshaft unis. I dropped the rear shaft out and drove it on the front - NO NOISE. so, new uni joints in the tailshaft, back together, NOISE IS BACK! The old uni joints were in pretty good shape but one had some brinelling on one trunnion so I got excited for a while there. so the lift has gone back in, it appears it was not contributing to the whine. Andrew I have not tried those longer lower arms yet but if it's still noist at stock height, I don't think they're going to help.

in summary, the noise is coming from the rear driveline. it is NOT the diff, it is NOT the transfer case, it is NOT the gearbox (no noise in FWD). it is NOT the tailshaft uni joints. the wheel bearings are new. the noise is only there on drive at speeds between 50 - 80 and 105+, maybe all the way from 50+ but I have difficulty hearing it between 80 - 100.

remaining possibilities:

tailshaft slip spline? it has about 1mm radial slop in it when installed.

so I'll chase up another tailshaft and swap it it there, see what happens.

other than the tailshaft, does anyone have any other bright ideas? This one has really got me stuffed.

take rear axles out and drive on front dif. this will tell you if it is your diff or not. if it whines it is not your diff.

Is there a possibility it has something to do with your 10mm cap head conversion on the rear hub/axle's? Perhaps one of them is ever so slightly misaligned, which is causing a diff whine under load at high speed? A tiny amount of preload on the axle might cause some grief!!!

I could be way off track but i've heard the tail shaft could cause a noise depending on the steel its manufactured from wall thickness etc...

Brian
Are the rear unis lined up in parallel to eachother, and is the front shaft unis at 90 degrees to eachother as per std?
Other than that, you mention the noise was less with no lift....the only thing that changes there is uni angles and slip joint lengths....
Andrew

carts wrote:Is there a possibility it has something to do with your 10mm cap head conversion on the rear hub/axle's? Perhaps one of them is ever so slightly misaligned, which is causing a diff whine under load at high speed? A tiny amount of preload on the axle might cause some grief!!!

possible I guess, but unlikely. the axles still have the factory dowels and they line up fine. keep 'em coming though.

dow50r wrote:Brian
Are the rear unis lined up in parallel to eachother, and is the front shaft unis at 90 degrees to eachother as per std?
Other than that, you mention the noise was less with no lift....the only thing that changes there is uni angles and slip joint lengths....
Andrew

I am leaning towards slip joint - either too much slop or not enough engaged length, maybe I should whip up a very short spacer and see...

when you changed out the diffs, did you do the pinion bearings? did you change out the pinions with the ring gears? is something touching the body or summat else?

otherwise you could just turn up the stereo and wait for it to go bang.

thats my noob suggestions

Can you borrow another rear tailshaft ?
Seems to be the problem from what you've described. It could be the slip joint creating a harmonic which is amplified by another part of the vehicle, like the transfer gears or the tailshaft tube ??

Good luck, I hate these kinds of problems.

Hi Dumbdunce. You say that when you were driving on the front diff the noise was gone yet with the rear diff connected up again, even with new unit joints. I know you said above it isn't the diff but are you sure? It does sound to me like the crown wheel to pinion backlash is not set up correctly. I believe from your previous posts that you are quite mechanically capable so I am sure you would know that when the backlash is not set up correctly you will get whine particularly when on throttle.

What do you think?

Cheers
Simo

rockcrawler31 wrote:when you changed out the diffs, did you do the pinion bearings? did you change out the pinions with the ring gears? is something touching the body or summat else?

otherwise you could just turn up the stereo and wait for it to go bang.

thats my noob suggestions

brand new bearings in the diff, and gear sets were changed - crownwheel and pinions are matched sets, you always have to change both.

nothing touching the body that I can see but good idea.

quick60 wrote:Can you borrow another rear tailshaft ?
Seems to be the problem from what you've described. It could be the slip joint creating a harmonic which is amplified by another part of the vehicle, like the transfer gears or the tailshaft tube ??

Good luck, I hate these kinds of problems.

I think this is heading in the right direction, yes. Dave (DX80) has offered me a tailshaft swap to experiment, I just have to make the time to go and give it a shot.

Simo63 wrote:Hi Dumbdunce. You say that when you were driving on the front diff the noise was gone yet with the rear diff connected up again, even with new unit joints. I know you said above it isn't the diff but are you sure? It does sound to me like the crown wheel to pinion backlash is not set up correctly. I believe from your previous posts that you are quite mechanically capable so I am sure you would know that when the backlash is not set up correctly you will get whine particularly when on throttle.

What do you think?

Cheers
Simo

well to me, it does sound a LOT like a diff noise - so much so that the diff has been built three times - twice by me with different gears, then again by a shop. when I got it back from the shop, before I installed it I loaded it into the vice and checked the crownwheel backlash and the contact pattern, which were both excellent.

that doesn't mean it's definitely NOT the diff - like if there is some distortion in the diff casing or something that misaligns the gears when the bolts are all done up, or gremlins in there somewhere. I have a few other diffs around the place, I might jam a known good 60 series diff in there just for fun if the tailshaft thing doesn't net any results.

anyway it's going for a run to Anna Bay on the weekend so I'll pack some loud CDs and pretend like I can't hear it.

any other suggestions?

DD, a quick swap of the tailshaft might just save you rebuilding the bugger for a fourth time. Unless you like doing it for shits and giggles!!

watching with interest, I have a Full Time GXL whines from about 80k's up, take foot of the loud & it goes away...
this weekend I will check the oils, drive it up to 80-100 in 4th & simple things that have been mentioned here...
It really only started around the time I put the 2" OME kit on but a 2" lift wouldn't cause much of a problem would it? or is it just arse?

DX80 wrote:DD, a quick swap of the tailshaft might just save you rebuilding the bugger for a fourth time. Unless you like doing it for shits and giggles!!

absolutely, I'll be around probably tues arvo if that suits. I'll only touch the diff again if the tailshaft gives no joy - plenty with the sh1ts and not so much with the giggles!

dumbdunce wrote:

Simo63 wrote:Hi Dumbdunce. You say that when you were driving on the front diff the noise was gone yet with the rear diff connected up again, even with new unit joints. I know you said above it isn't the diff but are you sure? It does sound to me like the crown wheel to pinion backlash is not set up correctly. I believe from your previous posts that you are quite mechanically capable so I am sure you would know that when the backlash is not set up correctly you will get whine particularly when on throttle.

What do you think?

Cheers
Simo

well to me, it does sound a LOT like a diff noise - so much so that the diff has been built three times - twice by me with different gears, then again by a shop. when I got it back from the shop, before I installed it I loaded it into the vice and checked the crownwheel backlash and the contact pattern, which were both excellent.

that doesn't mean it's definitely NOT the diff - like if there is some distortion in the diff casing or something that misaligns the gears when the bolts are all done up, or gremlins in there somewhere. I have a few other diffs around the place, I might jam a known good 60 series diff in there just for fun if the tailshaft thing doesn't net any results.

anyway it's going for a run to Anna Bay on the weekend so I'll pack some loud CDs and pretend like I can't hear it.

any other suggestions?

Sounds like a toughie. I agree try the other tailshaft as they are easy to change and then another diff centre if you know it is a good one. Ahh the joys of motoring Still beats the sh@t out of walking

Joombi wrote:watching with interest, I have a Full Time GXL whines from about 80k's up, take foot of the loud & it goes away...
this weekend I will check the oils, drive it up to 80-100 in 4th & simple things that have been mentioned here...
It really only started around the time I put the 2" OME kit on but a 2" lift wouldn't cause much of a problem would it? or is it just arse?

how many km? full timers can suffer from front diff noise as early as 150,000km but more common at 200,000+ - first step would be drive in 4th/5th to see if the noise is the same or different to isolate the gearbox as a source, then lock in the centre diff and drive on the front only, then the rear only, to see if the noise is isolated to one end or the other.

good luck with it, hope you don't have to throw fistfuls of cash at it.

dumbdunce, did you get rid of your noise? I have it in mine around 80km/h or so, rather annoying, I simply gave up in the end and bought a new Hilux lol

Still drives fine, I would doubt very much that it'd die.

I actually loose the noise when I remove the front shaft.

Hmmm!

have you tried leaving your wife at home when you drive it have you got the right oil in the diff i herd that if you have the wrong oil in it it will do that

how many km? full timers can suffer from front diff noise as early as 150,000km but more common at 200,000+ - first step would be drive in 4th/5th to see if the noise is the same or different to isolate the gearbox as a source, then lock in the centre diff and drive on the front only, then the rear only, to see if the noise is isolated to one end or the other.

good luck with it, hope you don't have to throw fistfuls of cash at it.

DD, yeah, mine has 270Kks, will try what you've suggested..
thanks again...