Gear Upshifting At The Wrong Rpm

[xXx]

Gents, need your expertise on a technical issue one of my friends is facing with his Montero. I apologize in advance for the shady description I’ll try my best to explain the issue the way I understood.

According to my mate he feels that sometimes the gear up shifts automatically at the wrong RPM (vehicle is an auto tranny) he can actually feel the engine jerk just like during a normal transmission when this happens. Agent has told him to replace the entire gear box at a cost of just over 700k. According to my personnel experience remedy for any issue at the agents is to replace the bit that’s causing the issue. Is there anything else that can be done to rectify this problem other than a full replacement?

[The Don]

Gents, need your expertise on a technical issue one of my friends is facing with his Montero. I apologize in advance for the shady description I’ll try my best to explain the issue the way I understood.

According to my mate he feels that sometimes the gear up shifts automatically at the wrong RPM (vehicle is an auto tranny) he can actually feel the engine jerk just like during a normal transmission when this happens. Agent has told him to replace the entire gear box at a cost of just over 700k. According to my personnel experience remedy for any issue at the agents is to replace the bit that’s causing the issue. Is there anything else that can be done to rectify this problem other than a full replacement?

First of all that is the classic UM response. Its BS, and I'm sure they haven't even diagnosed what the problem is, just know a new gear box will fix it ! I mean their whole attitude towards vehicle maintenance is this ! just ridiculous. Companies like A*W have a far more pragmatic approach !

Unless there is a warranty issue you should be able to replace the gear box with a used one for much less.

The problem with auto boxes in SL is there are very few technical experts who understand them well enough to re condition or rebuild them properly and also in a lot of scenarios its cheaper safer and more straight forward to just replace with a used one. I hope somebody else in this site can recommend a good technician for auto boxes ....

I mean its possible the problem is with the sensor or the gear box ecu, or it could be the torque converter, but somebody would have to take a good look at it find out what the problem is. I'm sure UM hasn't bothered !

[Overdrive]

DON'T KNOW IF THIS HELPS..

Adjustments

There are several problems that can be resolved with an adjustment (A simple adjustment is one that can be made without removing the transmission from the vehicle.)

If a transmission is shifting too early or too late, it may require an adjustment to the throttle cable. Since throttle cables rarely go out of adjustment on their own or due to wear and tear, these mis-adjustments are usually due to other repair work or damage from an accident. If the vehicle has a vacuum modulator instead of a throttle cable, there is an adjustment that can be made using an adjustment screw in some modulator designs. In vehicles with modulators, however, it is very important that there are no vacuum leaks and the engine is running at peak efficiency. Engine vacuum is very sensitive to how well the engine is running. In fact, many technicians use a vacuum gauge to diagnose performance problems and state-of-tune. Many problems that seem to be transmission problems disappear after a tune-up or engine performance related repair was completed.

SOURCE

http://www.dolphintransmissions.com/transmission.htm

[Elvis_Pil]

Machan OD- I think the Montero should have 'drive by wire' so no throttle cable.

See this is why I hate auto tranny's.. You're at the mercy of the agents. xXx I think you should take this a reputed garage like say 'aut#force' and get it checked before doing anything. My TP-12 had a similar issue- turned out to be the revolution sensors-that needed changing, but cant say for sure if its the same issue. Is this a CVT box?

[Arc Angel]

machan I recall an old thread on auto lanka which stated that Ajith (0777383526) was somewhat of an expert on auto boxes.. you could give the guy a shout and see if he seems useful.

[miniace]

machan I recall an old thread on auto lanka which stated that Ajith (0777383526) was somewhat of an expert on auto boxes.. you could give the guy a shout and see if he seems useful.

He is THE auto box expert!

MINIACE

[xXx]

Boys, thank you for your voluble input.

Mini don’t know if it got a CVT box if its any help it’s a 2003 brand new one. Do you guys know where this Ajith fellows garage is???

[miniace]

Boys, thank you for your voluble input.

Mini don’t know if it got a CVT box if its any help it’s a 2003 brand new one. Do you guys know where this Ajith fellows garage is???

Garage is in Seeduwa.400m from Seeduwa junction towards Raddolugama.

MINIACE

[miniace]

Monteros got INVECS-II ,computer-controlled automatic transmissions which studies the driving style, using the Adaptive Shift Control software.

The computer is the main cause of Tranny problems of Monteros where no cure is possible in SL other than replacing.If the snag caused by a mechanical defect,no need to panic.

MINIACE

[xXx]

The computer is the main cause of Tranny problems of Monteros where no cure is possible in SL other than replacing.If the snag caused by a mechanical defect,no need to panic.

Mini replace what the whole gear box or just the computer?

[The Don]

Mini replace what the whole gear box or just the computer?

Think according to Mini, if the issue is with the Transmission ECU, only the ECU need to be replaced.

I do remember Devinda mentioning a chap who can apparently repair some ECU problems, perhaps he can help. The most important thing is to identify the cause of the problem. I guess UM wasn't very helpful with that ? Usually a plug in scan should reveal problems with the ECU ! (I mean a trained technician will spot the irregularities straight away, they often tend to manifest as sensor errors though the sensors them self are ok !)

[Elvis_Pil]

Doubt that there is anyone in SL who can sort out an ECU issue with a Montero

[Devinda_Z]

I do remember Devinda mentioning a chap who can apparently repair some ECU problems, perhaps he can help. The most important thing is to identify the cause of the problem. I guess UM wasn't very helpful with that ? Usually a plug in scan should reveal problems with the ECU ! (I mean a trained technician will spot the irregularities straight away, they often tend to manifest as sensor errors though the sensors them self are ok !)

Prasad is more of a Toyota specialist , but you can try getting in touch with him on 0773-573228 and see if he know anything about this issue...

[miniace]

Mini replace what the whole gear box or just the computer?

Very unfortunately local agents stopped selling the Tranny ECU only.They practice selling the whole tranny unit and that cost more than 6 laks.But try your sources with UM might come out lucky you know.First I recommend a second opinion from an autobox specialist before replacing the unit through agents.Good Luck!

MINIACE

[RACERSEDGE]

better check with ajith ayya ..n tht ecu expart is also in wattala ..i heard he did a majic for a montero 2-3 mnths back..

[terrance]

have you changed your transmission oil ?? i have found that a simple "service " oil change fixes a lot of the transmission problems. many people in sl forget to change the transmission oil..

[Car Maniac]

have you changed your transmission oil ?? i have found that a simple "service " oil change fixes a lot of the transmission problems. many people in sl forget to change the transmission oil..

Yeah! I also agree with you dude. A similar type of over shifting,under shifting and poor pickup trouble occurred with my fathers Suzuki swifts auto tranny. Then we took it to the garage of Mr. Lal Alaw!#*# in Battaramulla and he went a test drive and recommended to change oil and see first. Then we changed oil from him and after the oil change, the vehicle has a significant performance improvement. From the day we bought it one year ago, all the time we got really low fuel consumptions from it like 9kmpl though it is 1.3L. Now it does around 11kmpl on the same routes. So I believe the ATF oil change has worked positively. AFAIK the regular ATF oil changing period is every too years or after driving 40,000 kms whichever comes first. So check ur mileage and oil condition. I recommend you to take ur vehicle to the above person, because he has lot of expertise and he personally diagnoses the vehicle troubles by driving them himself in test runs. Though this oil change looks like a minor service, sometimes it might correct ur problem as it corrected mine. I dont think an oil change will cost you more than 8000 - 9000 Rs for a SUV like urs with all oil charges and labor charges. So rather than paying lakhs for a gear tranny, wouldn't it worth trying first????

Wish you all the best!

Edited August 31, 2008 by Car Maniac

[RACERSEDGE]

mmmmm....

[miniace]

have you changed your transmission oil ?? i have found that a simple "service " oil change fixes a lot of the transmission problems. many people in sl forget to change the transmission oil..

Agreed 100%

MINIACE