Hi all, I am a newby here. Anyway I have 2000 Montero Sport with 128k on it.
About 3 weeks ago I started noticing between 20-40 MPH and 1500 to 2000 RPM the truck is bucking or jerking. I see RPM gauge move up and down about 1/4 inch as it is doing this.
Giving it more gas or downshifting seems to stop it temporarily. I have not had the problem at highway speeds. I am afraid the tranny is going. Any suggestions or has anyone else had this problem?

 

same **** happened in my 90 eclipse it's like hesitating, bucking, hpoing, jerking what ever you wanna call it. first of all check all ur filters (ie fuel filter and air filter) clean em and replace the fuel filter. then check ur plugs& wires & distributor. check for cracks anything suspicious replace it. pretty much tune-it up. see if it helps. also check ur timing belt, ur IAC (idle air control) or ur pcv (positive crankcase ventilation.) remember ther are only 3 imprtant things for a engine to run smoothly. 1)fuel 2) ignition 3)air. also check for vacuum leaks. this will probably solve ur problem. let me know if it helps. peace!!

 

Your problem lies in the lockup torque converter. The 2000 and newer Montero Sports require a specific ATF (Mitsu SPIII) to be used as the transmission can be very picky if something other is put in. Using other fluid can lead to the premature breakdown of the lockup Torque ConverterClutch. What you're feeling is the TCC locking and slipping over and over again. There is a Mitsubishi TSB regarding this concern. The only means of repair is to try FLUSHING the transmission with new SPIII ATF. This will take at LEAST 12 quarts of fluid and specialized equipment. Many auto repair centers will have the equipment to do that job but YOU MUST USE MITSU SPIII ATF PERIOD- therefore i suggest you take it to your local dealership for a flush. DO NOT BELIEVE ANYONE TRYING TO SELL YOU SOMETHING THAT THEY CLAIM TO BE EQUIVELANT TO THIS ATF. If the flush is not successful, you'll have no other choice but to replace the torque converter. Good luck!

Joel, CA

 

I may try draining the fluid and replacing the filter first as I have 128K on it.
Does anyone have a good guess on how many oints or quarts I will need to when I drain it by taking the pan off?

Thanks for you help.

 

I understand that you want to keep costs down by doing the job yourself, but keep in mind that a majority of the fluid is held in the torque converter itself. There is no means of draining it through the pan, therefore you'll only be changing roughly half (+/-) of the total fluid and mixing the new with the old. Since the goal is to get ALL of the contaminated and/or incompatible fluid out of the transmission, i'd still recommend going with the flush- otherwise the TCC can fail completely and you'll have no choice but to replace the torque converter. In information is based both on my 8 year experience as a dealership technician AND an actual printed TSB from Mitsu on this matter.

Joel, CA

 

Understood, I know that the fliud is NOT incompatible as I am the original owner and Nothing has been done in 128,000 to it. I figured I would try that first and if it doesn't work then I would go for a flush and or tranny rebuild.

What do you think?

 

Even without compatibility issues- it would be best to get as much of the dirty fluid out as possible. With that being said, there IS a way you can flush the transmission yourself WITHOUT specialized equipment if you want to give it a try. Go ahead and replace the transmission filter as planned, seal the pan, and refill the transmission with SPIII. From there, you'll need to remove the skid plate and locate one of the transmission cooler hoses at the base of the radiator. Back track it to one of the steel cooler pipes next to the transmission and disconnect it from there. Connect a rubber hose to this steel line and place the other end in a bucket. With the factory hose you just disconnected, aim it down into the bucket extending it if neccesary to reach the bucket. Once your fire up the engine- the transmission front pump will start pumping clean fluid throughout the transmission, valve body, and torque converter- OUT to the cooler. This clean fluid will drive out the dirty fluid remaining in the internals of the trans including the Torque Converter. Since you've got this hose disconnected- it will pump it directly into the bucket. You'll get to see just how filthy and contaminated this fluid is. The VERY SECOND the ATF flow starts to sputter with air- shut off the engine and refill the transmission again to repeat the process. Do this over and over until the fluid coming out is as clean as the fluid you're putting in. The reason why i ask you to get both ends of the hose into the bucket is that there are two lines from the transmission- one is the flowing OUT to the cooler and one is flowing IN from the cooler. Depending on which side you disconnect- the dirty fluid may come out of either end. It's better to be safe and have both ends leading into the bucket than to have the dirty fluid shoot all over the place. This procedure is actually printed in the FSM though i've hardly ever had to do it this way since we have the specialized equipment to do the job automatically. (this method works on any auto trans)

If this isn't detailed enough- just let me know before you start and i'll do my best to give a better explanation.

Good Luck!

Joel, CA

 

i have the same probelm with my 2001 2.4 cylinder gs eclipse but mine is a 5 speed manual no converter????

 

i also get a mis fire some times in 3 an2 and then in cyl 1 as well

 

Check the dates before you post, this thread is from 05.