Discovery G.Box/T.Case whine - speed related

[chosen]

G'day all,

I'm wondering if someone can give me some advice?

Problem: my 'new to me' 1996 V8i Discovery has in the last few days started to make a terrible whine:mad: It is getting progressively louder and sounds like it is coming from the Gear box or Transfer case.

I have inspected and replaced the oil in GBox, TCase and rear Diff but all seemed relatively clean with hardly any shards of metal on the magnets (totally normal at 8,000 km since last changed).

The noise is speed related, it began sounding only when under load (normal acceleration) but is now rearing its head while engine braking down hills.:eek:

Today while stationary I put the vehicle's tranfer box in Neutral and ran through the gears. I heard a noise like a clicking or something from the same area - oh no!


Any clue what the problem might be, how bad and how much:( ?

Thanks in advance,

chosen.

[harry]

ok,
chosen, how long have you owned the vehicle and how many km's on it, and how many km's have you driven it?
it is very hard to fault find a problem without some sort of history, and when you have a 'new to you' vehicle you, [and i] try harder to hear things.
one of us here on this forum will be able to help you.
could you please advise where you are, [update your profile] and maybe we have a member nearby that can help, perhaps even come and drive in your car and hear the whine you are asking about.
i hope we can find your problem is not a problem, land rovers sometimes have their own particular sounds and vices.

[Blknight.aus]

the whine "might" be your diffs... if its not its a misalignment of the gears in either the Tcase or the Gearbox due to wear. Sometimes a simple adjustment of preloads and thrust washers will correct this problem other times the gears are worn to the point where they will keep doing it even when correctly adjusted. Driven nicely a worn gear set can still last a bloody long time.

The clicking, depending on how its happening could be one of a few things...

If it happens once when you change gears its nothing to worry about immediately as its the driveline slack in the tcase being taken up after power is applied to the gears which have slowed due to the oil..

If it happens continuosly without hearing it I will guess at it being the tcases main input gear floating on the gearbox ouput shaft and "rattling" on the splines.

but it could also be one of the following

If your getting "notching" while crawling in first at idle (check both ranges) it might also be a chipped tooth on a gear somewhere in the case.

depending on how quickly you went through the gears it could also be the gearbox pump picking up pressure/slack when you lift your foot off of the clutch.

Till we get the culprit picked Im not going to even speculate a price.

Best of luck

[DRanged]

G'day all,

I'm wondering if someone can give me some advice?

Problem: my 'new to me' 1996 V8i Discovery has in the last few days started to make a terrible whine:mad: It is getting progressively louder and sounds like it is coming from the Gear box or Transfer case.

I have inspected and replaced the oil in GBox, TCase and rear Diff but all seemed relatively clean with hardly any shards of metal on the magnets (totally normal at 8,000 km since last changed).

The noise is speed related, it began sounding only when under load (normal acceleration) but is now rearing its head while engine braking down hills.:eek:

Today while stationary I put the vehicle's tranfer box in Neutral and ran through the gears. I heard a noise like a clicking or something from the same area - oh no!


Any clue what the problem might be, how bad and how much:( ?

Thanks in advance,

chosen.

Where are you;)

[chosen]

Thanks a lot for all the replies... I am located in SA (Torrens Park - Eastern Suburbs), I have owned the car for almost 2 months now, I purchased it in Sydney and drove it back to SA. I have driven over 5000kms so far and use it every day. The Disco has around 175,000kms on the clock and a GREAT service history, first 100,000kms it was serviced every 8 - 10kkms and the last 70,000 odd kms it has been services every 5 - 7kkms.

This Disco is my first and I am used to my previous 4x4, a tight Japanese Hilux, BUT this is definitely a little more than just British workmanship.

The noise is hugely amplified if I drive in low range by the way.

Thanks again for the responses thus far.

chosen

[ladas]

Just a wild out of the court idea - but could it be that the TC is 'wound up'

The solution to this is to either put the CDL on or off (bugger can't remember - somebody will know) and reverse the vehicle about 50 yards.

Again just an idea.

[chosen]

Just a wild out of the court idea - but could it be that the TC is 'wound up'

The solution to this is to either put the CDL on or off (bugger can't remember - somebody will know) and reverse the vehicle about 50 yards.

Again just an idea.
Thanks for your reply ladas,

I'd love it to be that simple, if it was 'wound up' wouldn't the hi/low range box be impossible to get out of gear(it is easy to)?

Cheers,

Andrew

[ladas]

Thanks for your reply ladas,

I'd love it to be that simple, if it was 'wound up' wouldn't the hi/low range box be impossible to get out of gear(it is easy to)?

Cheers,

Andrew

Not sure - somebody will know - I have only read enough to be dangerous:D

[Blknight.aus]

nope just changing gear from high to low would still be easy....

the TCase has a diff with a lock in it.. If youve driven it for prolonged periods on firm roads the marginally different front and rear axles speeds (different tyre size due to tyre wear say) will "bind" the center diff in the locked position.

To unlock it, Select reverse, CDL unlocked and back up it will usually come out in the first 20m or so but sometimes it will take up to 100m or so. IF its still showing as locked you might have an electrical short, Leave it unlocked, in neutral with the park brake on, jack up one front wheel and rotate it, if it spins freely the CDL is disengaged if it turns a little and then stops the CDL is bound up...

if its stuck ideally you get under the vehicle and check that the linkages are still on and working correctly then you just rock the jacked up wheel back and forth untill it freely rotates...

difficulty changing ranges due to transmission wind up is more or less limited to the driveline types found in the series type rovers (and the current toyos and the like that still use that system) and once you were in neutral on the tcase that pretty much relieved the problem.. (that doesnt guarentee that you wont have hard range changes for other reasons tho)

[chosen]

Oh yeah, it has a vacume CDL - the light would still be on if the CDL was locked on wouldn't it (it works at the diff not at the gear activation right)? Thanks Dave for explaning it further to me.

Any way, I think if the CDL was locked on I would've completely destroyed her with wind up by now!

Cheers,

chosen

[ladas]

Oh yeah, it has a vacume CDL - the light would still be on if the CDL was locked on wouldn't it (it works at the diff not at the gear activation right)? Thanks Dave for explaning it further to me.

Any way, I think if the CDL was locked on I would've completely destroyed her with wind up by now!

Cheers,

chosen

The CDL works off the Hi-Lo - Diff Lock lever in the cab, I would guess that the vacumn ONE is for your front or rear diff locks.

Now for the centre diff to be 'wound up' it doesn't nessesarilly mean that it's stuck in 'lock'.

On the D1, from memory I didn't think there was a light to advise you that the CDL was engaged, but I may be wrong (old age you know).

So to recap - the CDL the one in the transfer case, not in the axle diffs, can be wound up - even though the CDL is not engaged.

Have you tried the revering manouver ?

[chosen]

Cheers Ladas, well I'll try it this morning just in case - it'd be so good if that was all it was!

There is a light that comes on in the Disco S1 when CDL is engaged. I'm pretty sure that when you put the Hi/Low Gear leaver into Diff lock side it engages a vacuum CDL - I don't as yet have front/rear diff locks (anyone wanna donate some).

There are currently only two main vacuum lines off the engine... one to the brakes, the other to a funny box then under the car (assumed to CDL).

Like I said I'll try reversing today as it'd be good if that is all it is ;-)

Thanks,

chosen.

[ladas]

Cheers Ladas, well I'll try it this morning just in case - it'd be so good if that was all it was!

There is a light that comes on in the Disco S1 when CDL is engaged. I'm pretty sure that when you put the Hi/Low Gear leaver into Diff lock side it engages a vacuum CDL - I don't as yet have front/rear diff locks (anyone wanna donate some).

There are currently only two main vacuum lines off the engine... one to the brakes, the other to a funny box then under the car (assumed to CDL).

Like I said I'll try reversing today as it'd be good if that is all it is ;-)

Thanks,

chosen.

The CDL on a D1 is a mechanical device, it doesn't use a vacuum - unless of course yours has been modified.

From the hi-Lo / diff lock lever next to the gear stick - there is a mechanical linkage to the CDL actuator.............again unless yours has been modified.

If you PM me your email address I will send some pictures/details of the linkage

Where is this 'funny' box under the car ? Do you have pics ?

[Caveman]

The HI/Low lever in the D1 is a mechanical linkage to the transfer case.

The other vacuum line you saw is most likely the one for the cruise control, which goes from the throttle body to the vacuum control box in the front left of the engine bay.

Only the later D2's had vacuum activated transfer cases, due to LR removing the linkage to the lever.

DOH...just beaten by Ladas...!!! :)

[BigJon]

Only the later D2's had vacuum activated transfer cases, due to LR removing the linkage to the lever.



Only LT95 4 speed transmission / transfer cases had vacuum operated diff locks. All LT230 type transfer cases are pure mechanical engagement from factory. Some Disco II transfer cases do not have any diff lock activation at all.

[ladas]

Only LT95 4 speed transmission / transfer cases had vacuum operated diff locks. All LT230 type transfer cases are pure mechanical engagement from factory. Some Disco II transfer cases do not have any diff lock activation at all.

As BigJon said - however some people who did not have any diff lock actuators have fitted after market ones, some being linkages, some being electric motor driven (AMV) some with linkage adaptors that work off the high low - giving you CDL in low only, and I do understand that some vacuum aftermarket adaptors were fit - but all these were aftermarket jobbies - on the D2 - 1999 - 2003 range. Some D2's (late 2001 - late 2002/early 2003) didn't even have the 'guts' of the CDL inside the transfer case, and that is a whole new ball game - isn't it Jon

[jddisco200tdi]

I have had a similar problem in my disco.
The answer was the transfer case intermediate shaft lost its preload and created a wear pattern on the gears.
So even when it was rectified it would still whine loudly.

[chosen]

I have had a similar problem in my disco.
The answer was the transfer case intermediate shaft lost its preload and created a wear pattern on the gears.
So even when it was rectified it would still whine loudly.

:oThat's interesting, did it still make a (now let me describe it right) gritty sounding, slightly crunchy vibrating whine when the Hi/Low gear box was in neutral and you go through the gears - especially in 4th and 5th?

I took it for a nice and long reverse drive just now and it has made no difference - end of diff lock theory???

The sound as I just described is being produced even when the Transfer case isn't engaged - would this mean that the problem is with the gearbox?

Thanks again to all who have commented thus far,

chosen.

[chosen]

The HI/Low lever in the D1 is a mechanical linkage to the transfer case.

The other vacuum line you saw is most likely the one for the cruise control, which goes from the throttle body to the vacuum control box in the front left of the engine bay :)

Ok, this is a photo of the funny box...
http://www.sculptures.com.au/4x4 Forum pictures online/The Vacuum thingy.jpg

The cruise control has also just recently stopped working (for another post on another day) - wanna test that very vacuum control box once this whine problem has been rectified.

Any idea what that funny vacuum box thingy is for guys?

Cheers,

chosen.

[ladas]

Ok, this is a photo of the funny box...


The cruise control has also just recently stopped working (for another post on another day) - wanna test that very vacuum control box once this whine problem has been rectified.

Any idea what that funny vacuum box thingy is for guys?

Cheers,

chosen.

That is the charcoal canister, part of the emmission control system, it absorbs excess fuel vapour and purges it back to the fuel tank.

[chosen]

That is the charcoal canister, part of the emmission control system, it absorbs excess fuel vapour and purges it back to the fuel tank.
Ok, well I feel a little dumb now - at least it is clear to everybody that the CDL if not vacuum operated on my S1 Disco.

Back to the whine guys... any further thoughts? (I humbly ask)

[Caveman]

The cruise control has also just recently stopped working (for another post on another day) - wanna test that very vacuum control box once this whine problem has been rectified.
Cheers,

chosen.

I had a similar problem with my cruise control.......it was a split in the vacuum hose at the T-piece behind the window washer reservoir.
Check out all the hoses, as they are probably perished by now.

Cheers
Paul

[chosen]

I had a similar problem with my cruise control.......it was a split in the vacuum hose at the T-piece behind the window washer reservoir.
Check out all the hoses, as they are probably perished by now.

Cheers
Paul

There is still vacuum at the very end of the pipe near the vacuum pump (front passanger side) if I suck on it. The hose at the T-piece is all good too. Did the cruise control light come on (or did it try to work) when you engaged it whilst it was broken?

Cheers,
chosen

[chosen]

While I remember, the 2 months or so that I've owned this Disco there has been a fair bit of back lash in the gearbox/transfer case/diffs or somewhere anyhow. I don't know if this sheds some more light on the whine problem.

On ya all!

[Blknight.aus]

:oThat's interesting, did it still make a (now let me describe it right) gritty sounding, slightly crunchy vibrating whine when the Hi/Low gear box was in neutral and you go through the gears - especially in 4th and 5th?

I took it for a nice and long reverse drive just now and it has made no difference - end of diff lock theory???

The sound as I just described is being produced even when the Transfer case isn't engaged - would this mean that the problem is with the gearbox?

Thanks again to all who have commented thus far,

chosen.

OH CRUD... ok so im on the ummm dunno woodtsock but

if its the 77 driving the lt230 your primary support bearing in between the 3rd/5th (4th is direct remeber) is worn and the outpust/layshaft gears are doing the same hting as per the earlier post on the lt240 intermediate shaft....

if your lucky youve caught it in time and the mainshaft and layshaft are ok (albiet on the limit of wear) then is new bearings and live with the noise....

its actually cheaper to get a reco box than it is to outright purchase the main shafts and layshaft + bearings and the synrocs on 3rd + 5th that will be shot as well...


Yee hah....

HTF Im wrong....

[Caveman]

There is still vacuum at the very end of the pipe near the vacuum pump (front passanger side) if I suck on it. The hose at the T-piece is all good too. Did the cruise control light come on (or did it try to work) when you engaged it whilst it was broken?

Cheers,
chosen

Yes, the cruise control light did come on, on the switch with mine.....it just didn't hold the spedd when you pressed the set button.
My vacuum pump was fine, just with the leak, the control bellows on the throttle body was unable to move the throttle cable to adjust the speed.

Mine was a simple vacuum leak.

[ladas]

OH CRUD... ok so im on the ummm dunno woodtsock but

if its the 77 driving the lt230 your primary support bearing in between the 3rd/5th (4th is direct remeber) is worn and the outpust/layshaft gears are doing the same hting as per the earlier post on the lt240 intermediate shaft....

if your lucky youve caught it in time and the mainshaft and layshaft are ok (albiet on the limit of wear) then is new bearings and live with the noise....

its actually cheaper to get a reco box than it is to outright purchase the main shafts and layshaft + bearings and the synrocs on 3rd + 5th that will be shot as well...


Yee hah....

HTF Im wrong....

Wont be a 77 on a 1996 Disco, it will either be a R380 manual or a ZF4 auto

[Blknight.aus]

seee , Eye for details,,, that goes wright out the window when your drunk.....


which explains why uyou pickk up ugly women at 3 am in the morning during a bender.... and i aint talking about the precocious robot from futurama...

[chosen]

seee , Eye for details,,, that goes wright out the window when your drunk.....


It sure does, he he he!!!


OK well I have for you all a very bad quality recording of one of the sounds... 5th gear revving with the Hi/Low box in Neutral. You can just make out some of the crunching sound. It is only 486KB so wont take long to download.

5thGearNeutral.mp3 (http://www.sculptures.com.au/4x4 Forum pictures online/5thGearNeutral.mp3)

PS, I have a daily updated version of AVG Professional Virus Scanner - I'm confident it's clean but it is your choice to download it.

[chosen]

Yes, the cruise control light did come on, on the switch with mine.....it just didn't hold the spedd when you pressed the set button.
My vacuum pump was fine, just with the leak, the control bellows on the throttle body was unable to move the throttle cable to adjust the speed.

Mine was a simple vacuum leak.
Cheers, with the cruise control in my Disco no lights come on when I press the activation button nor does it try to engage. Funny as I drove all the way back from Sydney with it working fine - it just stopped working too!

I'm thinking this problem might be either the vacuum pump or electrical.

chosen ;-)

[ladas]

I'm thinking this problem might be either the vacuum pump or electrical.

chosen ;-)

If no lights - that would lead me to think electrical

Can't really hear the audio file at all :(

[chosen]

If no lights - that would lead me to think electrical

Can't really hear the audio file at all :(
Glad you concur with the electrical theory - where to start (probably at pump) if someone knows if there is a common fault with these Cruise Control systems it might save me some time ;-)

Yeah, I'm sorry about the audio file. It was recorded on my laptop using its in built mic. Just turn all your volumes up and ask the family to quite down for a sec and maybe, just maybe you'll hear it.

chosen

[ladas]

Glad you concur with the electrical theory - where to start (probably at pump) if someone knows if there is a common fault with these Cruise Control systems it might save me some time ;-)

If you have no lights - it means that the problem is before the pump - the pump is the last place to look. I'll check the diagrams.

Yeah, I'm sorry about the audio file. It was recorded on my laptop using its in built mic. Just turn all your volumes up and ask the family to quite down for a sec and maybe, just maybe you'll hear it.

chosen

You can hear a pin drop in my office - still can't hear much.

[duff]

A quick check for your cruise control is the brake disconnect valve.

At the top of your brake pedal there is a vacuum dump valve, that disengages your cruise control when you brake.

I have seen more than once that the line to this falls off or splits,, the car thinks you are braking all the time(as far as cruise is concerned).
From what I can pick up an elec failure on the series one cruise is rare but the rubber hoses are getting old and split or fall off easily

[ladas]

Glad you concur with the electrical theory - where to start (probably at pump) if someone knows if there is a common fault with these Cruise Control systems it might save me some time ;-)

Yeah, I'm sorry about the audio file. It was recorded on my laptop using its in built mic. Just turn all your volumes up and ask the family to quite down for a sec and maybe, just maybe you'll hear it.

chosen

As not to dilute this thread away from your gearbox problem I will PM the details I know regarding the cruise control.

Keep this thread on the gear box it's more important than the cruise problem.

[chosen]

A quick check for your cruise control is the brake disconnect valve.

At the top of your brake pedal there is a vacuum dump valve, that disengages your cruise control when you brake.

I have seen more than once that the line to this falls off or splits,, the car thinks you are braking all the time(as far as cruise is concerned).
From what I can pick up an elec failure on the series one cruise is rare but the rubber hoses are getting old and split or fall off easily

Thanks to all who have been giving me advice for my problems with both the whine in the gearbox and the cruise issue that was brought up during this topic.

I am pleased to inform you all that the Cruise Control is now fixed, it was as duff said, to do with the vacuum dump valve. My big boots had somehow knocked it and it was as if it was continuously braked.

Cheers,

chosen


AS THERE SEEMS TO BE LITTLE MORE ADVICE YOU GUYS CAN OFFER WITH REGARD TO THE WHINE ISSUE WITHOUT SEEING THE VEHICLE YOURSELVES, CAN ANYONE ADVISE ME WHERE IS A GOOD PLACE TO TAKE HER TO SORCE THE PROBLEM (in SA) - THEN I CAN SEE IF IT'LL BE CHEAPER TO REPLACE THE BOX?

[chosen]

G'day all,

I got under her today with a stethoscope and determined that the crunchy/gritty noise is coming from the transfer case - makes me much happier as it will no doubt be cheaper to repair than a gearbox problem.

I now must take it to a professional to repair/replace, anyone got anyone they can recommend for the job in SA?

Cheers,

chosen

[chosen]

Okie Doke, Today I adjusted the Bearing Preload (intermediate gears) in the TC, it has taken up the slack in the Case. The noise is still there, may be just warn gears but I suspect it is the bearings also. I'll drive it around until/if it starts getting noisier and then pull the whole thing out and do the blasted bearings or replace it then...

Cheers all