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

[dieseldriver]

Having problems with my truck not wanting to shift until the rpms get really high. On a good day it will shift at 1. 75k rpms but most the time it does not shift till 2 - 2. 5k rpms. riding at 25 mph it stays so high i feel like i can't go anywere and have to play with the gas to get it to kick in.



I was told by someone it is my torque converter. Is there and adjustment that can be made to make it shift sooner? Just bought the truck a few days ago and it shifted fine but on day 2 noticed this problem. Very frustrated because the last truck i bought did the same thing on day 2 also. Seems like some days it might work and others it might not.



please help

 

[Cosmo]

There is no adjusting the torque converter, but you may have an electrical problem. It's either electrical, or a hydrolic pressure problem.

 

[JLandry]

What year truck are we talking about?



How many miles on the odometer?



John L.

 

[dieseldriver]

It is a 2001 with 185k. The guy I bought it from says he had the trans. rebuilt 40k ago. As i said its frustrating because the last truck I bought did the same darn thing the next day, not while i was test driving it. I hope its nothing major

 

[JLandry]

OK, thanks for the info on your truck.

Another question: Is this delayed shift problem only from 1st to 2nd, or is this happening in all gears?

If this is happening in all gears, then the first fix I'd try is to replace the Output Shaft Speed Sensor which is located on the overdrive gear case at the rear of the transmission. It's an inexpensive plastic part which takes less than 5 minutes to replace and can be purchased at any auto parts store for around $20 or less. It's used by the PCM (Powertrain Control Module) to control transmission shift points.

If this delayed shift problem is only occurring between 1st and 2nd gears, let me know and I'll post info on dealing with that.

Regards,

John L.

PS: Welcome to the TDR forum!

 

[dieseldriver]

It seems like it might go into first ok but 2nd and up seems to be delayed a lot. think it delays on 3rd gear too, heck i don't think i've had the truck out of 3rd or 4th gear at 70 mph. Riding thru town down main street and the rpms are wayyy to high as i notice people looking. I noticed when i test rode it before purchasing that it would shift a little late but it was not as bad as it is now. I did have a company clean the engine but they seemed to be careful with it in the process.

It may even be doing this with all the gears now that i think about it.

thanks for your help.

 

[dieseldriver]

I also wonder if when they were cleaning the bottom end of the engine if they ruined the Output shaft speed sensor. Could this be ruined with water and cleaning agents?

 

[JLandry]

Go ahead and replace the Output Shaft Speed Sensor and let me know if that changes the shift behavior. While under the truck, it'd be a good idea to carefully inspect the wire harness connected to it for any damage or breaks.



Is it safe to assume you've checked the transmission fluid level per the instructions in the owner's manual?



John L.

 

[dieseldriver]

I checked the transmission fluid level with the engine off and it is in the max ok position on the dipstick. I'll go ahead and pick up the part tomorrow. where abouts is the sensor located at?

 

[DavidC]

I checked the transmission fluid level with the engine off and it is in the max ok position on the dipstick. I'll go ahead and pick up the part tomorrow. where abouts is the sensor located at?

Needs to be running in neutral and up to temp.

Dave

 

[DavidC]

I also wonder if when they were cleaning the bottom end of the engine if they ruined the Output shaft speed sensor. Could this be ruined with water and cleaning agents?

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

 

[dieseldriver]

when you say up to temp. i guess i could let the engine idle a while because i can ride this thing for an hour and the temp gauge only moves 1/8" tops.

 

[dieseldriver]

think i might need a new thermostat unless this is normal in 40degree weather

 

[JLandry]

when you say up to temp. i guess i could let the engine idle a while because i can ride this thing for an hour and the temp gauge only moves 1/8" tops.

The transmission needs to be up to full operating temperature. A good 30 minute drive on a highway should do it. The tip of the transmission dipstick should feel hot to the touch, but won't burn you.



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 have an ohmmeter, never used one so i'm not sure what setting to put it on

 

[JLandry]

think i might need a new thermostat unless this is normal in 40degree weather

That doesn't sound normal. For comparison, the coolant in my truck will have reached full temperature after about 20-25 minutes of freeway driving at 60mph even in freezing temperatures. It has a 190 degree thermostat.



When you replace the thermostat, since you don't know the true maintenance history, it'd be a good opportunity to flush out the old coolant and replace it with a fresh 50/50 mixture of DISTILLED water and new long-life coolant.



If you need a service manual for your truck, you can download it HERE.



John L.

 

[dieseldriver]

The transmission needs to be up to full operating temperature. A good 30 minute drive on a highway should do it. The tip of the transmission dipstick should feel hot to the touch, but won't burn you.

John L.

I'll take her out and check it. so after i'm done have it in neutral and read the dipstick. Should be in the ok cross grid section or high up in the hot section? there is a couple ways you could read this thing not to sound dumb

 

[DavidC]

I'll take her out and check it. so after i'm done have it in neutral and read the dipstick. Should be in the ok cross grid section or high up in the hot section? there is a couple ways you could read this thing not to sound dumb

I usually read the back side of mine as the front usually gets muffed up sliding in and out. As for the ohmmeter if you have a 1k setting use it. You are trying to read 600 ohms, even the highest setting should give you a reading just may have to move the decimal around.

Dave

 

[JLandry]

I'll take her out and check it. so after i'm done have it in neutral and read the dipstick. Should be in the ok cross grid section or high up in the hot section?

Yes. For more information see the factory service manual I linked to in a previous post.



John L.

 

[dieseldriver]

thanks, i'll take a look. 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?