How to justified the cause of transmission whine

[happyguy007]

Hey guys, I would need some help in to dignosist the transmission whine which appear in my mitshubishi lancer 2000.
The whine only appear after reaching operating temperature, high pitch, start around 60Km/h and most pronouce on 95km/h.
The noise is more significant while accelerating and decelerating, however it still can be heard while gear in neutral. May i have some opinion from u guys whether the noise is from output bearing or final gear? when the car stop moving or i press in the cluth, the noise is totally eliminated.

thank you.

 

[Bluestream]

I would guess the bearings are worn, and after the fluid thins out at operating temps, they start to whine

 

[Craig in Canada]

Originally Posted By: Bluestream
I would guess the bearings are worn, and after the fluid thins out at operating temps, they start to whine


Note that he says that the noise goes away if he presses in the clutch. That doesn't sound like transmission bearings to me since they're all still spinning regardless of clutch engagement. Although he states that it comes back if he puts it in neutral while underway.

 

[aquariuscsm]

Input shaft bearings maybe? I can hear mine spinning when the clutch is out,and then stop when the clutch is pushed in. Perfectly normal,as all manual transmission cars do this. Mine has never whined though. Have you changed the fluid since ownership?

 

[dkrivosheyev]

Originally Posted By: aquariuscsm
Input shaft bearings maybe? I can hear mine spinning when the clutch is out,and then stop when the clutch is pushed in. Perfectly normal,as all manual transmission cars do this. Mine has never whined though. Have you changed the fluid since ownership?


I've done a lot of research on the transmission whine. If the whine happens under load only, then most likely it is the final gears. If the whine remains even with the clutch pressed then I agree with the input shaft bearing going out

 

[Bluestream]

Originally Posted By: Craig in Canada
Originally Posted By: Bluestream
I would guess the bearings are worn, and after the fluid thins out at operating temps, they start to whine


Note that he says that the noise goes away if he presses in the clutch. That doesn't sound like transmission bearings to me since they're all still spinning regardless of clutch engagement. Although he states that it comes back if he puts it in neutral while underway.



When you push in the clutch, the transmission stops spinning.

 

[happyguy007]

Hi aquarius, i change the gear oil on every 50k miles or one year which ever come 1st. Dkrivosheyev, the noise is most pronounce under slight load,(slight acceleration)and slight deceleration during high speed. The noise gets higher pitch as the speed increase.

Today i notice that the noise will be greatly eliminate when i cruising when there are totally no acceleration or deceleration. a slight load would makes some whine....Guys,is there anyway to defferentiate d source of noise just by the nature of the sounds?

I hope to keep the transmission running for another 3 years atleast. Wonder what i can do to prolong it life span so that i would not need to change the whole gear box.

thank you guys for the sharing.

 

[dkrivosheyev]

Originally Posted By: happyguy007
Hi aquarius, i change the gear oil on every 50k miles or one year which ever come 1st. Dkrivosheyev, the noise is most pronounce under slight load,(slight acceleration)and slight deceleration during high speed. The noise gets higher pitch as the speed increase.

Today i notice that the noise will be greatly eliminate when i cruising when there are totally no acceleration or deceleration. a slight load would makes some whine....Guys,is there anyway to defferentiate d source of noise just by the nature of the sounds?

I hope to keep the transmission running for another 3 years atleast. Wonder what i can do to prolong it life span so that i would not need to change the whole gear box.

thank you guys for the sharing.



From this additional description it looks like it is the final drive gears (the differential) making the noise. How loud is the noise? If you open both front windows at 60mph can you still hear the noise over the wind? Do you have this noise at speeds below 30 mph?

 

[mechtech2]

Originally Posted By: Craig in Canada
Originally Posted By: Bluestream
I would guess the bearings are worn, and after the fluid thins out at operating temps, they start to whine


Note that he says that the noise goes away if he presses in the clutch. That doesn't sound like transmission bearings to me since they're all still spinning regardless of clutch engagement. Although he states that it comes back if he puts it in neutral while underway.



Huh?? No.
The trans input bearing is likely here.
Parts are not all still spinning with the clutch in.

 

[Craig in Canada]

Originally Posted By: mechtech2
Originally Posted By: Craig in Canada
Originally Posted By: Bluestream
I would guess the bearings are worn, and after the fluid thins out at operating temps, they start to whine


Note that he says that the noise goes away if he presses in the clutch. That doesn't sound like transmission bearings to me since they're all still spinning regardless of clutch engagement. Although he states that it comes back if he puts it in neutral while underway.



Huh?? No.
The trans input bearing is likely here.
Parts are not all still spinning with the clutch in.


The OP isn't clear. He says that the noise stops when he stops moving *OR* whenever he presses in the clutch. At 55mph, press in the clutch and leave it in gear - which parts of the transmission are stationary at this point? None.

The OP should be more clear - I think I saw some followups from him but haven't read it all yet.

 

[aquariuscsm]

This probably has no relation at all,but I see you`re driving a Mitsubishi.............I had a 1998 3000GT SL that was an automatic. It would whine when I`d give it gas and put a load on the transmission,and under load only. Like I said,it probably has no corelation since mine was an auto and yours is a manual,BUT,same symptoms........whining under load.

 

[happyguy007]

Craig, the whine do stop while i do the followings (car is moving):
1. press in the clutch;
2. free the gear to neutral;
3. to feather the throttle so that there is neither acceleration nor deceleration.

thanks for everyone's input

 

[dkrivosheyev]

Originally Posted By: happyguy007
Craig, the whine do stop while i do the followings (car is moving):
1. press in the clutch;
2. free the gear to neutral;
3. to feather the throttle so that there is neither acceleration nor deceleration.

thanks for everyone's input

I think this must be the final drive gears

 

[Colt45ws]

Is there a difference in whine with RPM or speed. ie. if you are in 5th at a speed and load that whines does going to 4th change the pitch? Or is it even still hearable?

 

[mechtech2]

Whether coasting or with the clutch in, the input is not loaded.

 

[rpn453]

Your mounts could be contributing to the noise. I have a few different transmission mounts, and the stiffer ones make the transmission a lot more audible. A hardened or worn out mount could potentially do the same. Probably not the likely scenario, but I thought I'd throw it out there.