97 Jimmy 4x4 3&4 gear shifting problem

Hi , i have 97 Jimmy 4x4 4L60 automatic transmission. I have problem with shifting from 2 gear to 3 and up. In D position car starts moving normally and changes from 1 gear to 2 also normally (2500 rpm), but in 2500 rpm with 2 gear it just takes gear off and nothing happens. I tried to 5000 rpm and once it changes to 3 gear but not anymore. 1,2 and rear works fine.I tried to reset computer (battery trick)but nothings gone better. Gearbox have new oil and filter, also replased all pistons and seals. After first repairing the gearbox works fine about 5 days(was problem with all shifting).Also its never takes shift down if i accelerate. Any ideas.

Are you calling the automatic transmission the gear box?
Any check engine or transmission lights on?
It needs to be put on a engine/transmission capable scanner and codes and data and shift data read out.
Check for codes and clear codes with the scanner and see if any come back.
Post back all code no's.

On a 97 always check the ign switch for good voltage in and out.
97 was bad year on ign switches.
Is the fluid level and fluid condition still good.

Does it shift the same in OD as it does running threw gears?

What pistons and seals were replaced?

Apologises for my bad english.No check lights.I try to find here (Estonia, Tartu) any GMC capable scanner. Fluid level and condition is OK. How to i check the OD. I cant find any OD switch in car. They told me that they used replasment set from 4L65 (Hummer) gearbox.I can't tell you exactly wht they changed but they say tht everything with mechanical parts was OK. Tomorrow first i check Ignition swich. Also i feeled before that gearbox has 2 different shifting modes. 1 one- when i start car and shift to D, the car shifts 1 gear and all others gears very smoothly(i cant feel any shiftings) and 2 mode- its shifts roughtly after starting to 1 and 2-nd and rear. and those "mode"s changes after i stop the car and ignition off and on ,but not all the time.

Apologises for my bad english.No check lights.I try to find here (Estonia, Tartu) any GMC capable scanner. Fluid level and condition is OK. How to i check the OD. I cant find any OD switch in car. They told me that they used replacement set from 4L65 (Hummer) gearbox.I can't tell you exactly what they changed but they say that everything with mechanical parts was OK. Tomorrow first i check Ignition switch. Also i feel before that gearbox has 2 different shifting modes. 1 one- when i start car and shift to D, the car shifts 1 gear and all others gears very smoothly(i cant feel any shiftings) and 2 mode- its shifts roughly after starting to 1 and 2-nd and rear. and those "mode"s changes after i stop the car and ignition off and on ,but not all the time.

No problem on english.
My english and spelling is not good either.

There is no OD switch.

OD is turned shifted on and off by the transmission computer.
Different gears are switched by shift solenoids in transmission and controlled by transmission computed.

You need a transmission/engine capable scanner.
GM tech scanner or snap on scanner that is transmission capable will do it.
Just a OBD 11 scanner does not get into good transmission data or codes.

Can the place that changed gears scan it for you or check electrical part?
If you can get the codes and post back codes we can help.

No problem on english.
My english and spelling is not good either.

There is no OD switch.

OD is turned shifted on and off by the transmission computer.
Different gears are switched by shift solenoids in transmission and controlled by transmission computed.

You need a transmission/engine capable scanner.
GM tech scanner or snap on scanner that is transmission capable will do it.
Just a OBD 11 scanner does not get into good transmission data or codes.

Can the place that changed gears scan it for you or check electrical part?
If you can get the codes and post back codes we can help.


They dont have any GM capable scanner, but maybe they find it for me. Also they told me that transmission computer inside box was with oxide. Ofcause its theyr problem to fix that, but i need to drive with car and hope find fast resolution to that problem by myself. How do i know is it OD on or off

A good transmission scanner will give you all shifting data and what gear it is in.
Good Luck and let us know how it goes.

not good news but it sounds like your 3-4 clutches are shot. That usualy means a rebuild. It's not likely you have a transmission rebuilder there so your best bet is to get a GM rebuilt and find a shop that will do the remove and reinstall.

not good news but it sounds like your 3-4 clutches are shot. That usualy means a rebuild. It's not likely you have a transmission rebuilder there so your best bet is to get a GM rebuilt and find a shop that will do the remove and reinstall.
yeah, its not good news, hopefully not so bad situation and only have solenoid or some electrical problem because we dont have here good GM store and those guys who repair my transmission have lot of experiences of repairing automatic transmissions. They also have 2 4L65 boxes and can change broken parts from those. Firtst of i check today ignition swich and maybe they find some code scanner.

I check'd today ignition swich and oil again and all is OK.Oil is clear and red and also all OK wit voltage from swich.Tomorrow i try to find some scanner to scan trouble codes.

Scanner show me TPS fault (no any transmission fault codes)and measuring potensiometer shows that there is no impediance. Now i ordered new TPS and tomorrow i change this.

Scanner show me TPS fault (no any transmission fault codes)and measuring potensiometer shows that there is no impediance. Now i ordered new TPS and tomorrow i change this.


A bad TPS sensor will mess up transmision shifting.
Let us know how it goes with new tps sensor.

TPS is changed but no results.Trans trouble is the same how was. Only acceleration and 1 and 2 changing goes much better. Now i drived with car to repairshop were they made first repair and today evening (maybe) i hope , i get some answeres, what and why. Also when i drived, i notice some creapy noise (like metal to metal) from trans when rpms goes over 1000 and if the trans changed from 2 to 3 then noise is gone but car stays like in N.
First time when trans was broken i heard similar noise. OK, now i only wait, what they say me.
PS! no any trouble codes anymore

Them noises do not sound good.
Let us know how it goes.
Good luck

Hi, now the box is in pieces and 3-4 gear clutch disks are burned and black. Also in back of piston is like black jelly. Also in oil is like black pepper very small pieces. Is it possible tht something is wrong with turbine or maybe TPS fault was reason for 3-4 clutch burning?

Hard to say.

But it is time for another complete transmission.

Be sure to flush the rad cooler when installing another transmission.

After it is installed get it on a good transmission scanner and check things out.
Also check ign switch good.
Or you may burn up another transmission.
Let us know how it goes,
Good luck

Hi , i have 97 Jimmy 4x4 4L60 automatic transmission. I have problem with shifting from 2 gear to 3 and up. In D position car starts moving normally and changes from 1 gear to 2 also normally (2500 rpm), but in 2500 rpm with 2 gear it just takes gear off and nothing happens. I tried to 5000 rpm and once it changes to 3 gear but not anymore. 1,2 and rear works fine.I tried to reset computer (battery trick)but nothings gone better. Gearbox have new oil and filter, also replased all pistons and seals. After first repairing the gearbox works fine about 5 days(was problem with all shifting).Also its never takes shift down if i accelerate. Any ideas.

There is a seal that connects the intermediate and rear shaft in your transmission. The seal is plastic and over time it becomes brittle. A major problem is if the blazer has been towed with the rear tires on the ground. Third and fourth gear are in the same drum assembly. If they are both not working, then your only option is a complete rebuild or a used transmission.

If this transmission was just rebuilt, and it burned the 3-4 that quickly, makes sure or make sure your mechanic/builder has installed the forward sprag assembly correctly and is engaging in the right direction. If installed incorrectly, it will burn the 3-4 clutches very, very quickly.