What kind of transmission fluid do I use for a 99 chevy tracker that's a manual

Question edited for clarity.

Try changing the auto transmission fluid, or at least topping it up. The demands of plowing snow are pretty ******* transmissions. Fully changing the fluid comes with its own problems. The best way is to drain the fluid, carefully measure and replace it with the same amount plus a couple of measured tablespoons extra.

https://www.google.com/search?q=1991+Geo+Tracker+auto+transmission+fluid+change

Recommended fluids and Oils

https://www.google.com/search?q=1991+geo+tracker+auto+transmission+fluid+recommended

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Automatic Transmission Fluid Capacities Automatic Transmission 3-Speed Pan Removal and Replacement 4.0 quarts After Complete Overhaul 6.9 quarts When draining or replacing torque converter, more fluid may be needed. Manual Transmission Fluid Capacities Manual Transmission 4-Speed Automatic Transmission Not Owner Serviceable Complete Drain and Refill 2.0 quarts

You need to replace your torque converter, your Transmission does not move/turn in any way while in park the only part that does is the torque converter. I would also get a full fluid change when that is done as well.

I’m happy to assist further over the phone at https://www.6ya.com/expert/brock_d67526d2a834c47e

Since you say gear oil I assume that it is a manual transmission. Here are codes and fluid type/capacity
Transmission fluid Capacity 2.0 liters
Transmission code: DYP, ECW, EFG, ERS, FBV, FBX, FBY, EGY, EVR, EZK, FCF Type G51 SAE 75w-90 (synthetic oil)
Transmission codes: DQY, DBZ, DZQ, DZC, EGC, EGF, EKG, EMR, EMS, ENH, ENJ, EBJ, EBP, EBQ, EZH, EWW, FBW, EGR, EBN, EGT, EGX, EGU, EHC, FDS, EHA Type G50 SAE 75w-90 (synthetic oil)

Standard Transmission ?

Sounds like you need a clutch sevice

the plug is usually on the right side, about 1/3 to 1/2 of the way up from the bottom.

I have a 99 chevy tracker and mine is behind the starter.

check fluid level, make sure proper fluid is in transmission otherwise take to trans shop to diagnse if level and type is correct(check at idle normal operating temp)

Sounds like a bad countershaft bearing. The trans will need removed and disassembled to fix it.