'93 Pajero 3000 V6 Whining Noise

[Connor]

Hey guys and girls,

I have a loud whining noise, (similar to the whine you get in reverse on manual transmissions) in my Pajero. It has a manual transmission. I have already done a oil change on the transmission but it did not solve it.

So, the whine is apparent in every gear and changes pitch with the engine RPM. However when I depress the clutch it completely disappears.

I've had a look at quite a few different forums and have seen people saying it's the clutch thrust bearing or the gearbox pilot bearing and all sorts of other stuff.

So, I'm posting my own thread to see if anyone can shed any light on the situation.

Cheers!

[disco stu]

Is it still there if car is in gear and coasting along, but foot is on clutch?

As a general rule that noise is pretty much always clutch thrust bearing. But if the noise is still there when the engine is disengaged from gearbox (foot on clutch), and the rear wheels are turning the front of the gearbox (still in gear) then you would be looking at the front end of the gearbox. The fact it only changes in response to rpm indicates front end of gearbox/clutch area as well. Just want to isolate it down exactly.

Whatever way it is a transmission out job

[tomwithannl]

When you have your foot OFF the clutch pedal your throw out (thrust) bearing is not under load and should NOT make a noise. Alternately with your foot ON the clutch pedal it is under load and if faulty WILL make a noise, therefore that is not your problem. The pilot bearing in the end of the crank (or in the flywheel) ONLY spins with the gearbox in gear and the clutch pedal depressed, like at a stop sign, so this is not your problem either.
My first thought would be a gearbox bearing. Although the front gear box bearing spins all the time (including when you are in neutral until you put your foot on the clutch) it can be quiet until it is put under load.
Just my thoughts

Tom

[disco stu]

Isn't there something different about the clutches in these that means the pressure gets taken off or something when changing gears? I'm yet to lay eyes on the clutch in mine, but going off what someone else was saying, but I didn't quite understand what they were getting at

Could it also be that with some pressure it gets quiet but its whiney as when its a bit looser? I've had bearings in the past that are better with a bit of load

[erad]

Probably the point you are concerned about the clutch being different from others is the fact that it is a pull type clutch rather than the traditional push type clutch - when you push the clutch pedal down, the throwout lever inside the clutch pulls the clutch plate off from the flywheel, whereas most systems use lever systems to push the plates apart. The big difference is when you try to dismantle the gearbox from the engine - you have to release the clutch fork first whereas in most systems, because it is a push type system, the fork comes away from the plate without any help. Whatever, the clutch throwout bearing is not your problem. It is difficult to explain....

Whatever, your clutch will not cause this noise. IF the throwout bearing is stuffed, it will protest when you push the clutch pedal down. The spigot bearing is normally not a problem either. That is mainly a guide bearing to support the clutchplate when the clutch has been disengaged (the clutch pedal is down). The noise is most likely coming form the bearing on the front or input shaft of the gearbox. Normally they are needle rollers, and maybe a roller has been mashed a bit. There should be plenty of oil there and I would not expect a catastrophic failure from this area. Not that I like running with crook bearings, but any bits which do fall off should hopefully get trapped by the magnetic drain plug, so that is the first place to look. When you drained the oil, did you see any bits stuck to the plug? If you didn't, I wouldn't worry too much.

The cost of removing/replace the gearbox, apart from the overhaul cost will be high - probably more than the car is worth. Unless you are scared of failure out in the middle of whoop whoop, I would just keep using the car as normal and ignore (if you can) the noise. Look ahead and try to line up a replacement gearbox for when you need it.

[Connor]

Is it still there if car is in gear and coasting along, but foot is on clutch?

As a general rule that noise is pretty much always clutch thrust bearing. But if the noise is still there when the engine is disengaged from gearbox (foot on clutch), and the rear wheels are turning the front of the gearbox (still in gear) then you would be looking at the front end of the gearbox. The fact it only changes in response to rpm indicates front end of gearbox/clutch area as well. Just want to isolate it down exactly.

Whatever way it is a transmission out job

Thanks for the reply. I never ride the clutch when coasting, but it is slightly hard to get the car into reverse at times and a few of the gears require a little force to get into, so maybe the clutch area?

I did notice that when i have the clutch depressed the noise is still there, but only very slighly.

[Connor]

When you have your foot OFF the clutch pedal your throw out (thrust) bearing is not under load and should NOT make a noise. Alternately with your foot ON the clutch pedal it is under load and if faulty WILL make a noise, therefore that is not your problem. The pilot bearing in the end of the crank (or in the flywheel) ONLY spins with the gearbox in gear and the clutch pedal depressed, like at a stop sign, so this is not your problem either.
My first thought would be a gearbox bearing. Although the front gear box bearing spins all the time (including when you are in neutral until you put your foot on the clutch) it can be quiet until it is put under load.
Just my thoughts

Tom

Cheers for your thoughts mate, Im beginning to think is a transmission job now. Its not an unbearable noise but it is pretty loud. I might just have to grin and bear it for a while longer!

Cheers

[Connor]

Probably the point you are concerned about the clutch being different from others is the fact that it is a pull type clutch rather than the traditional push type clutch - when you push the clutch pedal down, the throwout lever inside the clutch pulls the clutch plate off from the flywheel, whereas most systems use lever systems to push the plates apart. The big difference is when you try to dismantle the gearbox from the engine - you have to release the clutch fork first whereas in most systems, because it is a push type system, the fork comes away from the plate without any help. Whatever, the clutch throwout bearing is not your problem. It is difficult to explain....

Whatever, your clutch will not cause this noise. IF the throwout bearing is stuffed, it will protest when you push the clutch pedal down. The spigot bearing is normally not a problem either. That is mainly a guide bearing to support the clutchplate when the clutch has been disengaged (the clutch pedal is down). The noise is most likely coming form the bearing on the front or input shaft of the gearbox. Normally they are needle rollers, and maybe a roller has been mashed a bit. There should be plenty of oil there and I would not expect a catastrophic failure from this area. Not that I like running with crook bearings, but any bits which do fall off should hopefully get trapped by the magnetic drain plug, so that is the first place to look. When you drained the oil, did you see any bits stuck to the plug? If you didn't, I wouldn't worry too much.

The cost of removing/replace the gearbox, apart from the overhaul cost will be high - probably more than the car is worth. Unless you are scared of failure out in the middle of whoop whoop, I would just keep using the car as normal and ignore (if you can) the noise. Look ahead and try to line up a replacement gearbox for when you need it.

Thanks for replying mate.

When i drained the oil there was only a very small amount of very fine shavings on it. Nothing to be concerned about I think.

Yeah i think i will have to put up with for now and start looking around for a replacement gearbox. The car drives fine and dosent seem to be having too much trouble as it is.

Thanks for your time!