Engine/Transmission (1998.5 - 2002) truck does not shift soon enough

[B.G. Smith]

The torque converter won't lock and the transmission won't shift into OD if the ATF is below 50 deg. F. Just a thought since the truck is not warming up to normal temp. bg

 

[JLandry]

Just curious if the trans fluid is low why does it cause the trans to do this and can this happen if its just a little under?

Your transmission fluid level is probably fine. We're simply trying to help you eliminate the most obvious causes of transmission problems first before going into more complex adjustments and/or repairs.



Low fluid prevents the transmission from doing what it's supposed to do: Actuate hydraulic servos to change and hold gear selection and properly couple the engine to the drivetrain.



Too much fluid is also a problem by cause foaming, which effectively introduces air (which is compressible) into a system that's supposed to have a fluid in it (which is not compressible).



John L.

 

[dieseldriver]

Have an ohmmeter?. Pull the plug on the sensor and check across the sensor pins. Should read about 600 ohms. When ever I have found a bad sensor it usually reads open.



Dave

I found the sensor and pulled the plug put an ohm tester to it and shows nothing. the ohm tester i have has a few different settings choices reading. 200,2k,20k,200k,2m,20m so i'm not sure which one to do.



I did notice a what looks like a little shifter rod coming out of the trans that rubs against 1 of the 2 1/4" aluminum lines so i bent it over a little so it wouldn't rub.



going for the test ride now

 

[DavidC]

I found the sensor and pulled the plug put an ohm tester to it and shows nothing. the ohm tester i have has a few different settings choices reading. 200,2k,20k,200k,2m,20m so i'm not sure which one to do.

I did notice a what looks like a little shifter rod coming out of the trans that rubs against 1 of the 2 1/4" aluminum lines so i bent it over a little so it wouldn't rub.

going for the test ride now

Use the 2k. Touch the 2 meter leads together and verify the meter works, should read 0 ohms, maybe . 06 or something (reading actual meter leads). Do not put your fingers on the metal part of the probes as you will read your body resistance, then test across the 2 pins of the sensor. If the sensor again reads open it is bad and needs to be replaced. Open is usually what I find. If you ever need to check the rear differential sensor (usually for ABS, brake light in dash, intermittent speedo it is done the same way but should read around 1800 ohms.

Dave

 

[dieseldriver]

Ok, Went for a test ride and all the gears don't shift until 2000-2500. Once i'm rolling along at faster speeds it seems to shift a little better but still gives me probs. If i start up really slow sometimes i can get lucky and have it shift thru the gears at 1750rpm but its so far and few between. Starting up normal with traffic its pretty as it won't shift until 2000 - 2500 and takes awhile to snap out of it.

On the ohm meter when i touch the leads to see if the meter works i get 0 so it must be working. when i touch he 2 pins on the sensor it reads either 1 or . 014. When i turn the meter on and it is not in use it just reads 1 on the display screen.

 

[JLandry]

On the ohm meter when i touch the leads to see if the meter works i get 0 so it must be working. when i touch he 2 pins on the sensor it reads either 1 or . 014. When i turn the meter on and it is not in use it just reads 1 on the display screen.

Without seeing your Ohmmeter (sounds like you have it on a high scale setting), you probably need a new Output Shaft Speed Sensor. At only $15-20, I'd just go ahead and replace it. Worst case if it doesn't solve the problem, then at least you'll have a spare.



John L.

 

[dieseldriver]

10-4, will get one in early this week and see what happens.

 

[DavidC]

Ok, Went for a test ride and all the gears don't shift until 2000-2500. Once i'm rolling along at faster speeds it seems to shift a little better but still gives me probs. If i start up really slow sometimes i can get lucky and have it shift thru the gears at 1750rpm but its so far and few between. Starting up normal with traffic its pretty as it won't shift until 2000 - 2500 and takes awhile to snap out of it.

On the ohm meter when i touch the leads to see if the meter works i get 0 so it must be working. when i touch he 2 pins on the sensor it reads either 1 or . 014. When i turn the meter on and it is not in use it just reads 1 on the display screen.

With those readings it sounds like the sensor is shorted and not open maybe intermittent since the previous test was open. Either one is bad. Maybe pick up another and ohm before installing. You may have found your problem. I replaced mine a few years ago from Auto Zone, my original read open and the replacement 600 ohms.

 

[dieseldriver]

double check me since i'm a newbie to this stuff. below is a pic of the sensor to make sure i'm looking at the right one? and the other pic shows the tester i'm using set on 2k as dave told me.

thanks for all your help and patience

 

[JLandry]

double check me since i'm a newbie to this stuff.

You've got everything right.



John L.

 

[dieseldriver]

great! i'll be in touch

 

[DavidC]

put a pan under it if you do not want trans fluid on concrete etc. It tends to drip initially no large volume. Correct me if I am wrong John. It's been a while since I pulled mine.

Dave

 

[JLandry]

put a pan under it if you do not want trans fluid on concrete etc. It tends to drip initially no large volume. Correct me if I am wrong John. It's been a while since I pulled mine.

You're absolutely right Dave.



Transmission fluid will dribble out when you pull that speed sensor so you need to be ready for it.



John L.

 

[DavidC]

Another bit of info if you do not know. The pressure transducer and solenoid on these trucks can raise havoc. It usually entails not shifting out of 1st without leaving off the throttle slightly. A sure sign of this is being able to shift manually thru the gears. Remedy = transducer and solenoid replacement which requires trans drain and pan removal. Just a FYI.



Dave

 

[dieseldriver]

thanks for letting me know to put a pan underneath.

 

[B.G. Smith]

Next time you are under the truck, check the little shifter rod that you moved from hitting the aluminum lines. I'm thinking it may be the transmission throttle valve rod and may be stuck in the rearward position. With the truck throttle in idle positom the lever shoulbe sll the way forward toward front of engine. bg

 

[dieseldriver]

Next time you are under the truck, check the little shifter rod that you moved from hitting the aluminum lines. I'm thinking it may be the transmission throttle valve rod and may be stuck in the rearward position. With the truck throttle in idle positom the lever shoulbe sll the way forward toward front of engine. bg

Thanks B. G. I will give that a looking over too when i put the new sensor in.

 

[dieseldriver]

Ok, here is the update. I put the new sensor in and took it for a ride but it still does the same thing. it does not want to even come out of first gear till 2250-2500 rpm. I didn't take it far because of the rpms going so high.

Someone told me the other day to try adjusting the throttle valve cable. Could this be a probable cause?

At this point i'll just sit tight till i know the next step to take.

 

[DavidC]

Ok, here is the update. I put the new sensor in and took it for a ride but it still does the same thing. it does not want to even come out of first gear till 2250-2500 rpm. I didn't take it far because of the rpms going so high.

Someone told me the other day to try adjusting the throttle valve cable. Could this be a probable cause?

At this point i'll just sit tight till i know the next step to take.

Have you tried to shift manually thru the gears ?. Did you Ohm the new sensor ?

Dave

 

[dieseldriver]

Have you tried to shift manually thru the gears ?. Did you Ohm the new sensor ?

Dave

I tried shifting manually thru the gears by letting off the gas a little but it doesn't want to shift. the only way i can get it to shift is by stepping on the gas more to get the rpm's up. The ohm tester reads . 632 if i flip the leads it reads it jumps all over the place. I'm doing this with no key in the ignition by the way if that means anything to you.