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Discussion Starter · #1 ·
My trooper is having a hard time shifting. I have already cleaned the range mode sensor and all the lights on the dash are the same as which gear I am in.

Reverse works great. No hesitation or slipping. 1st gear also works great. But it has a very hard time shifting around 20-25mph. Also if I start the trooper in snow mode, it barely moves. It barely even crawls. What is my issue ?

Is it the shift solenoids ? If so where should I buy them ? and which ones ? Should I replace all 4 ? If its not the solenoids ? What else could it be ?
 

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The are only two shift solenoids, If it a shift solenoid problem it would be the 1-2/3-4 (Shift A) which is energized in second and third. You could check the resistance of this solenoid if you have a meter. Measure between Pins C and D on the 4 Pin main case connector.

Plenty of places on line to buy the solenoids, also Honda/Accura dealers.
 

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You should also check to see if the overdrive servo piston is leaking or stuck. I had very similar symptoms, the od piston was shot, leaking from a busted o ring. replaced it for about 230.00 including labor, been running fine ever since(about 5k miles so far).
 

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Looking at the transmission bellhousing first, bottom of the right side about center of the tranny and just in front of the pan, is a rubber circular cover for it, my transmission guy looked at it and knew it was bad, if there is evidence of leaking from out of that cover. There's a rubber ring gasket around the piston that rots(like rubber does), causing the piston to leak. I'm no expert, but it's worth checking off the list atleast. Sorry I'm having a hard time finding a linkable picture but they're out there if you search.
 

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If you measured you measured infinity across pins C and D of the transmission connector with the vehicle connector disconnected, the 1-2/3-4 (Shift A) solenoid coil is open or one of the wires from the connector to the solenoid coil is open. You will have to drop the main pan to investigate further.

A inoperative Shift A solenoid is consistent with your symptom.
 

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Discussion Starter · #10 ·
Thanks. I ordered new shift solenoids, trans filter, and fluid. I'm going to dive into the transmission tomorrow. Hopefully the solenoids come in by Tuesday. I'll post after I'm done and let everyone know how it went.
 

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Shift A does not function the same as Shift B, make sure you put the replacements in the correct location. Also, make sure you refill the ATF using the correct procedure, ie top it off with the engine running and warmed. Further, make sure to replace the drain and fill crush washers and don't over torque the pan bolts.
 

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Discussion Starter · #12 ·
Yeah I realize that they act differently. I intend to put one in one at a time. I planned to put in Castrol Import ATF Fluid. It's whats recommend correct ? I'm aware that you fill the transmission until it drips out the fill hole and then start it up warm it up to operating temperature and then fill it up some more until it drips again correct ? Should I try shifting the transmission out of park to L to get some of the fluid flowing in the transmission ? I have a snap on digital torque wrench for torquing the pan bolts. Do you happen to know what the torque is ?
 

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Dexron is a registered trademark of GM.
Castrol "Import Multi-Vehicle" claims to meet Dexron III H and prior specs, so it should perform satisfactorily. Castrol also sells "Dex/Merc" which it claims meets Dexron II, II E, III, and III H specs. I expect it will perform satisfactorily as well.

The Isuzu service manual does not require that the transmission be run through the gears during ATF refill.

The Isuzu service manual states that the pan bolt torque is 11 Nm, the fill and drain plug torque is 38 Nm and the filter bolt torque is 20 Nm.
 

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Discussion Starter · #17 ·
Finished putting in the new solenoids. It now shifts and I can reach highway speeds. It's now have a secondary issue. It seems to have a hard time catching 2nd gear and slams into 3rd gear. The Check Trans light has come on. Will a normal code reader be able to read the Check trans code ? Is there a way to read the code without a code reader ?
 

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Have you cleaned your range mode sensor? This can cause the transmission to slam into each gear.

I've always used Castrol Import Dex 3 with fantastic results for a long time.
 

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Discussion Starter · #19 ·
I did clean out the range mode sensor. That was the first thing I did. I'm getting a code reader from my brother on Friday. I'll determine my next route with the transmission after I get the Check Trans Code.
 

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When the Check Trans lamp is illuminated the CEL is usually illuminated and a transmission DTC is stored. In some instances the CEL is not illuminated and the problem can be a Pressure Control solenoid (aka Force Motor) problem. Transmission DTC's can be retrieved used the "flash code method" same as engine DTC's.
 
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