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420A 2gNT Transmission fluid

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Dsm_rider2000

Probationary Member
8
3
Dec 20, 2021
Houston, Texas
hey i just got a 1997 eclipse gs few months ago. When I bought I took the car to a mechanic to take a look at it because I dont really know much about cars. It’s my first project. He said the engine and transmission was in really good condition. Few weeks later I started struggling switching gears. I replaced the clutch master cylinder and the slave cylinder. It got better but still It get’s stuck when I try to engage 1st and 2 second gear. My thoughts would be I needs new transmission fluid , if so, what kind of transmission fluis does my car uses? The clutch is in good condition I did few test and seems to be good.
 
Keep in mind that when you are browsing the forums your car has an engine and transmission from Chrysler sor you'll see a lot of references to 420A, which isn't a pot reference, it's your engine, and the NVT350 transmission. Many parts are shared with the Mitsubishi powered turbo cars but the 2gNT cars have a unique powertrain.
 
When you get a chance, can you fill out a vehicle profile? It helps narrow down issues with vehicles.as far as transmission fluid.. i use this in my 93 gst, oem tranny.
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Do NOT use this in an NVT-350!! It will have detrimental effects on the synchronizers.

You have a few options for compatible fluids.

-High Mileage engine oil, Mobil 1, 10w-30.
- Mopar ATF +4
- Synchromesh

My trans was filled with regular gear oil when I purchased the car. It would always grind into 2nd gear. So I tore it down and replaced the synchro and bearings and filled it back up with ATF +4. After the first fluid change I switched over to Mobil 1 oil since it's easier to find and cheaper. I changed the fluid yet another time within a few days to make sure there wasn't any ATF still left behind contaminating the oil, although I don't think the mix would hurt anything.
 
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you forgot to mention Redline MTL
 
Do NOT use anything except a SYNCHROMESH fluid...... ATF+4 was for NVT350s years 2000 and up.

Usuable fluids are as follows.........

Amsoil Synchromesh
Royal Purple Synchromax
Valvoline Synchromesh
Pennzoil Synchromesh........
 
Do NOT use anything except a SYNCHROMESH fluid...... ATF+4 was for NVT350s years 2000 and up.

Usuable fluids are as follows.........

Amsoil Synchromesh
Royal Purple Synchromax
Valvoline Synchromesh
Pennzoil Synchromesh........
The reason the fluids I listed are recommended is because of the fiber-type material on the inner lining of the synchronizers. All the variations of the NVT-350 used this same material. They also all used the same end bearings. The gear stacks themselves were the difference between each. But you can use the same fluids in all variations of the NVT-350. I have personally used everything I listed and can verify functionality. And before me were the people who recommended it to me.

We're not limited to a specific type of fluid. And because of that we should consider ourselves lucky. At least one of the fluids I listed can be purchased damn near anywhere. Especially engine oil. I've been using 10w-30 since late 2020 because it's the easiest to source.
 
I've used only castrol oil my whole life without any issues on all Mitsubishies I have owned
I have this in my ESi and TSi, also had it in my Evo3, 4g92T Lancer and 2GRS and 1G GS
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I've used only castrol oil my whole life without any issues on all Mitsubishies I have owned
I have this in my ESi and TSi, also had it in my Evo3, 4g92T Lancer and 2GRS and 1G GS
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You put 75-90 in an NVT-350? Whatever floats your boat I guess. But it is NOT recommended.

My car had a burned up 2nd gear synchro. And nothing to blame besides the fact it was previously filled with gear oil. Low mileage. Noticed better shifting when using the fluids I listed too
 
You put 75-90 in an NVT-350? Whatever floats your boat I guess. But it is NOT recommended.
has served me well, no synchro problems, works like a charm!

also at Mitsubishi Imports we use only Castrol products, that's why I started use it tbh
 
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Consider yourself lucky then.

The Mobile 1 oil is out dated info. Ed Peters had a good run, but the formula has long since changed. I will only use a Synchromesh fluid, more specifically "Asmsoil Synchromesh" But then again I've also went through numerous transmissions over the years. My current one has gears 1 thru 4, 3/4 output, and Input shaft cyro treated and shot peened. Along with a 3rd gear from a 2010+ PT N/T. Lastly we applied an internal 3rd gear synchro stop to keep the synchro from over extending as they all do.

As for fluid, choose what make you "comfortable". However, I've went through enough transmissions that i wont take chances on fluids that are not originally recommended for them.
 
The good news is, if people mess up their transmission from the wrong fluid, there's no shortage on NVT-350's. Or any Chrysler transmission with the same bolt pattern. Any given day of the week I could go find some sort of replacement. Some of you might not be so lucky but there's still plenty out there.
 
IDK man........ there isnt many of the HDs left...... I see posts for 5 speeds almost every day. But if I were you, I'd treat them as if they're almost gone...... BC one day soon, they will be.
 
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