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

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.

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

Originally Posted by 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 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.

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

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

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.

Originally Posted by 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.

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

Originally Posted by chosen

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

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)