Mitsubishi Montero Sport Differential and Humming Sound Problem

[rvdedios]

In December 2009 I got my Mitsubishi Montero 2010. In the last week of January 2010 I traveled to Angeles City. Nothing serious, went through Angeles traffic, visited a satellite office, parked in the basement, etc. Going back to Manila on NLEX I could not go beyond 60kph because I was hearing metal to metal grinding in the rear. Obviously this was a rear assembly problem. Diamond Motors confirmed that the differentials have failed. A month old but NEW car with a differential problem sounds crazy and extraordinary. It calls for a replacement.

So they fixed it. The problem was there was a lot of performance issues, clicking/tucking sound beneath (loose U-joint), shift shocks etc. after it was done. A lot of business days wasted going to and from the dealer. No loaner car given. It looks like they nailed it last month when the Montero that I drive everyday seems to be running smoothly except for the shift shock abnormality from time to time. It is always good if you know that Mitsubishi plant engineers (the chief and senior ones) do the work - a little quality there.

But one thing they never fixed was the annoying humming sound at 75kph to 90kph. It stops at 90. The sound is high pitched, high frequency so you can hear it with stereos on. It only goes when you press the pedal. I've been waiting for Mitsubishi Thailand responses because they "referred" it to them but still NO action. All research tells us that it is still a rear axle/differntial problem from the pinion to the rear wheels. The car is going to be 2 yrs old in 3 months.

Anybody having this problem? Advice?

[111prez]

looks like you got a lemon unit. a differential failure is major for a one month old monty

best to have demanded a change of unit and not just a fix that did not solve your problems

[rvdedios]

Yep, really major. I gave them a chance after a demand letter from my attorney. Obviously, MMPC would say that it is "under warranty" and will be fixed by Mitsubishi. No lemon car law here in Phil. Soon, probably we should lobby for one to protect the rights of customers specially if defects like this are considered major i.e. "differential failure", "sudden acceleration", "surging" etc.

There is also a case that I know who had the same problem. So it is not just me.

[babynos01]

Yung sa amin din may humming when running at 80kph on 4th gear.
Below and above that, wala naman. Also changed the diff fluid nung 30k PMS. We are now at 52500 and no problems naman.

[urbanhopper]

Sir babynos01 did you change the type of fluid? Or same specs lang?


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[hachooro]

Yung sa amin din may humming when running at 80kph on 4th gear.
Below and above that, wala naman. Also changed the diff fluid nung 30k PMS. We are now at 52500 and no problems naman.

sorry for bringing up this old thread. would just like to get an update ano na nangyari?

transmission fluid lang ba pinalitan?

may humming sound din sa amin when running 80kph.

lalabas yung sound when you step on the gas pedal and maintain 80kph pero if you tried to step further to increase the speed, nawawala.

under warranty pa yung Montero, any one na naka experience pa ng ganito?

[babynos01]

^ganyan din amin haha.
Magincrease or mag slow down ka lang ng kaunti, nawawala siya.
Ordinary gear oil lang ginamit ko, yung sa Total. Now at 62k and hindi ko pa siya pinalitan uli. Sa 80k nalang haha.

[hachooro]

^ganyan din amin haha.
Magincrease or mag slow down ka lang ng kaunti, nawawala siya.
Ordinary gear oil lang ginamit ko, yung sa Total. Now at 62k and hindi ko pa siya pinalitan uli. Sa 80k nalang haha.

sa 80 kph lumalabas yung tipong nakaapak ka lang konti sa gas pedal para ma maintain yung 80kph, andun yung humming sound.

pero step to increase, nawawala.

sir, gear oil lang pinalitan mo, yung oil mismo sa differential?

ask ko na din po ilang liters?


hindi na po umulit yung humming sound?

[babynos01]

sa 80 kph lumalabas yung tipong nakaapak ka lang konti sa gas pedal para ma maintain yung 80kph, andun yung humming sound.

pero step to increase, nawawala.

sir, gear oil lang pinalitan mo, yung oil mismo sa differential?

ask ko na din po ilang liters?


hindi na po umulit yung humming sound?

meron pa rin sir haha.
harmonics na siguro yun. meron at meron talaga haha.
yup yung gear oil na nasa diff mismo, sae90 ata yung pinalagay ko sir.
kaunti lang yun sir. basta wag sobra.

[arsen]

meron pa rin sir haha.
harmonics na siguro yun. meron at meron talaga haha.
yup yung gear oil na nasa diff mismo, sae90 ata yung pinalagay ko sir.
kaunti lang yun sir. basta wag sobra.

MT at 2WD po ba mga units nyo?

MT 4WD lang kasi ang equipped with flexible flyweel na kagaya nito
http://www.valeoservice.com/data/mas...75.pdf?rnd=463

Sa MT kapag 4th gear wherein the engine and differential are basically directly coupled possible mag cross ang natural frequencies nila at magkaroon ng high frequency vibration.

Inherent na yan sa anything that spin fast. Maski jet engine ng airplane nga meron certain rpm na sobrang ingay.

[hachooro]

meron pa rin sir haha.
harmonics na siguro yun. meron at meron talaga haha.
yup yung gear oil na nasa diff mismo, sae90 ata yung pinalagay ko sir.
kaunti lang yun sir. basta wag sobra.

Hindi pala natanggal? Wag na lang natin steady patakbuhin ng 80kph, mas mabilis ata gusto. Hahaha!

Salamat sir, may tunog nga siguro talaga, mga jeep naririnig ko din yung tunog na ganun...

4x2 automatic po yung montero namin.


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[arsen]

AT tranny has torque converter so meron na sana built-in isolator ng drivetrain vibration.

Kaso for fuel efficiency, yung torque converter ng MS has lock-up clutch na kapag ang vehicle reaches a certain speed, the lock-up clutch physically links the impeller and turbine thereby changing the torque converter into a purely mechanical coupling (zero slippage).

So kapag nasa third gear ang 4AT na MS (gear ratio 1), katulad lang din sya ng MT na MS na nasa 4th gear naman (gear ratio 1 also) kaya pareho na directly link na rin ang engine sa differential.

Yeah better stay out of that CRITICAL SPEED.

By the way critical speed may vary depending sa driven load ng drivetrain (actual vehicle weight and wind speed)

[hachooro]

^ sir arsen i guess that explanation means its normal to have that sound.... Stay oiut of that speed na lang siguro.


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[motmot20]

May resolution na kaya yung humming sound at 80kph? I'm also experiencing this on my GLX 4x2 AT. It actually starts at around 78kph to 80kph..above and below that speed, nawawala naman.