Author Topic: Looks like the transmission is going out of my truck (Read 1249 times)

DalesCarpentry · « **on:** April 23, 2012, 03:04:53 PM »

Looks like the transmission is going out of my truck.

On my way to work this morning it stopped shifting. I have to let up on the gas pedal to get it to shift. I have no reverse in it. I put a bottle of that Lucas transmission treatment in it hoping that would help but it did not. The funny thing is it never gave me any warning that it was about to go. It's not slipping or anything like that. It just won't up shift on it's own and no reverse. I sure can't afford this right now. I guess I have to start looking around for a used transmission and find someone to install it for cheap. Dale

BUGEYE · « **Reply #1 on:** April 24, 2012, 01:24:24 AM »

mine did that. garage replaced the shift sensor.

yellowtail3 · « **Reply #2 on:** April 24, 2012, 01:49:34 AM »

taking a cue from Bugeye's post... surf the web a bit for some info on how-to... maybe something you can do yourself without having to remove/replace tranmission.

Here's hoping it's not as bad as seems...

Sourdough · « **Reply #3 on:** April 24, 2012, 07:53:43 AM »

While visiting my friends Dodge Durango started shifting hard, slamming into the lower gears. Took it to Amoco, they replaced a sensor. That was in October, shifting fine ever since.

Brett · « **Reply #4 on:** April 24, 2012, 08:59:24 AM »

My guess is a bad sensor also. Today's transmissions are all computer controlled and shift electronically.

DalesCarpentry · « **Reply #5 on:** April 24, 2012, 11:41:28 AM »

I had a guy at work today say it could be a sensor. I will have that checked out for sure but if it were a sensor would I lose reverse? Thanks Dale

mechanic · « **Reply #6 on:** April 24, 2012, 12:07:25 PM »

You also have shift solenoids Dale, if it is a later model.....late 80's or so and up. If a reverse solenoid is not working correctly, it could under certain circumstance cause other problems. Take it to someone you trust, they can usually hook up and monitor the transmission functions. Even a used transmission is not cheap...so hopefully it's something much simpler.

Ben

DalesCarpentry · « **Reply #7 on:** April 24, 2012, 12:13:45 PM »

Quote from: mechanic on April 24, 2012, 12:07:25 PM

You also have shift solenoids Dale, if it is a later model.....late 80's or so and up. If a reverse solenoid is not working correctly, it could under certain circumstance cause other problems. Take it to someone you trust, they can usually hook up and monitor the transmission functions. Even a used transmission is not cheap...so hopefully it's something much simpler.

Ben

My truck is a 98 Chevy Silverado 1500 4x4 with the 4.3 Vortec engine in it if that helps anyone tell me more like do you know what transmission I need to be looking for if it's not as simple as a sensor. Thanks Dale

mechanic · « **Reply #8 on:** April 24, 2012, 12:53:32 PM »

The junk yards will know Dale. We have replaced a couple in some of our company's older vans with used...one was $600.00, the other $800.00. It takes 4-6 hours to swap one if you are equipped.

Again....get it checked before you swap it....and another old trick, add a quart of regular brake fluid and drive it a bit. This will free up sticking spools, etc.

Ben

Cuts Crooked · « **Reply #9 on:** April 24, 2012, 02:16:11 PM »

Check around a lot before you do anything. I found a shop that rebuilt the tranny in my van for about the same price as buying a used tranny and having it swapped. Got a 5 year/50000 mile warrenty to boot!

hillbill · « **Reply #10 on:** April 24, 2012, 02:39:15 PM »

the fact that it gave you no warning could be a good sign.sounds more electronic to me than anything else. sniff the dipstick, if it does not smell burnt or funny then id have to say it may not be the tranny itself.once you get over 91 in chevy trucks they can do sum weird stuff that defys explanation but is often easily fixed. it could even be your computer under the dash or behind the right kick panel.like i said it dont always make sense.drop by orriellys if yu can and see if you can use there diagnostic tool to pull some codes. long shot but mite work.

scootrd · « **Reply #11 on:** April 24, 2012, 04:42:09 PM »

Could be the Power control module PCM itself, Have them throw a scan on it . if it coughs up a A reading of: "P0600," "P0601," "P0602," "P0603," "P0604," "P0605," "P0606," "P0607," "P0608," "P0609" or "P0610" Replace the PCM.

If it is one of the shift Solenoids, you should have a check engine light and truck will go into LIMP mode and only operate in 2nd gear.

When any one of these two Shift Solenoids fail, the PCM commands the Transmission to operate in LIMP IN MODE and this means that the Transmission will run in 2nd Gear only (no 1st and no 3rd or 4rth). The most common one is the Check Engine Light will be on with one of the following Diagnostic Trouble Codes:

P0751 1-2 Shift Solenoid Valve Performance (Shift Solenoid A Performance)
P0753 1-2 Shift Solenoid Valve Electrical (Shift Solenoid A Electrical)
P0756 2-3 Shift Solenoid Valve Performance (Shift Solenoid B Performance)
P0758 2-3 Shift Solenoid Valve Electrical (Shift Solenoid B Electrical)
Transmission runs only in 2nd Gear. This is known as running in LIMP IN MODE.

Both Shift Solenoids A and B are located toward the rear of the Transmission and you don't need to remove them to test them. After removing the Transmission Oil Pan, place your Multimeter in Ohms mode. disconnect the electrical connector of both Shift Solenoids. Once disconnected, measure the resistance of each one by probing the exposed soldered terminals of the Solenoids. With a cold tranny you should see 19 to 24 ohms.

Semper Fi

DalesCarpentry · « **Reply #12 on:** April 24, 2012, 04:59:34 PM »

Quote from: scootrd on April 24, 2012, 04:42:09 PM

Could be the Power control module PCM itself, Have them throw a scan on it . if it coughs up a A reading of: "P0600," "P0601," "P0602," "P0603," "P0604," "P0605," "P0606," "P0607," "P0608," "P0609" or "P0610" Replace the PCM.

If it is one of the shift Solenoids, you should have a check engine light and truck will go into LIMP mode and only operate in 2nd gear.

When any one of these two Shift Solenoids fail, the PCM commands the Transmission to operate in LIMP IN MODE and this means that the Transmission will run in 2nd Gear only (no 1st and no 3rd or 4rth). The most common one is the Check Engine Light will be on with one of the following Diagnostic Trouble Codes:

P0751 1-2 Shift Solenoid Valve Performance (Shift Solenoid A Performance)
P0753 1-2 Shift Solenoid Valve Electrical (Shift Solenoid A Electrical)
P0756 2-3 Shift Solenoid Valve Performance (Shift Solenoid B Performance)
P0758 2-3 Shift Solenoid Valve Electrical (Shift Solenoid B Electrical)
Transmission runs only in 2nd Gear. This is known as running in LIMP IN MODE.

Both Shift Solenoids A and B are located toward the rear of the Transmission and you don't need to remove them to test them. After removing the Transmission Oil Pan, place your Multimeter in Ohms mode. disconnect the electrical connector of both Shift Solenoids. Once disconnected, measure the resistance of each one by probing the exposed soldered terminals of the Solenoids. With a cold tranny you should see 19 to 24 ohms.

Semper Fi

I have no check engine light on and I can get it to shift through all the gears. So that means it could be the PCM then huh? Thanks Dale

LunaticFringeInc · « **Reply #13 on:** April 24, 2012, 08:30:46 PM »

Once again I am reminded of why I drive a older stick shift truck.
Yeah definitely check the sensors and the solenoids. That was a feaquent issue on my 95 Thunderbird!

magooch · « **Reply #14 on:** April 25, 2012, 03:08:34 AM »

Yessiree, I too will take a stick transmission any day, over an automatic.

coyotejoe · « **Reply #15 on:** April 25, 2012, 03:46:24 AM »

Well I just had the manual transmission rebuilt for my '89 GMC and that wasn't cheap either. But I suspect the old truck was used hard before I bought it two years ago. It was set up to pull a fifth wheel trailer so probably heavy loads and the trany was noisy when I bought it. Of course two years of insurance on a brand new truck would probably cost more than the rebuilt transmission, not even to mention depreciation.

Sourdough · « **Reply #16 on:** April 25, 2012, 05:52:23 AM »

Got ride of all my automatic transmissions. Well the KIA Sportage is still here, but it's on it's way out. No one drives it now. My new Jeep Unlimited has a six speed, as does the wife's RX-8, and the Mitsubishi Eclipse. All the rest have five speeds. Won't have another automatic. Wife hates them as well.

Wife went to lunch with a friend last week. Her friend drives a Chevy Tahoe with an Automatic. Marie got to feeling bad so Michelle decided to drive back to work. As she neared the gate she went to push the clutch to downshift, slammed on the brakes. The guard laughed at her and made fun of her knowing she usually drives a sports car with a six speed.

garbhead · « **Reply #17 on:** April 25, 2012, 05:56:37 AM »

Mine did that once...was vacuum line from engine to vacuum modulator on transmission, simply was unhooked....

scootrd · « **Reply #18 on:** April 26, 2012, 04:32:06 AM »

Hi Dale ,
Any update ?

Hope it was/is a relatively inexpensive fix.

DalesCarpentry · « **Reply #19 on:** April 26, 2012, 02:18:26 PM »

I have not been payed yet and am driving it like it is until I get payed so I can pay someone to look at it. Thanks Dale

Bugflipper · « **Reply #20 on:** April 26, 2012, 09:36:24 PM »

Here's a troubleshooting page for you Dale. http://www.gmtruckhq.com/?q=node/93

BTW I run that engine and transmission in a lot of the scouts I build and have them in a few I have kept. Most of the time you will not have the actual transmission to fail. They can be used for very severe duty behind a v8. I run one behind a 392 with more torque than a lot of diesels and it has held up well. The little 4.3 doesn't really put out enough power to bother it much, not even the trip to FL with the trailer. So things should work out pretty well for you. If it were going out odds are it would be slipping instead of not wanting to go to the next gear and reverse not working.

DalesCarpentry · « **Reply #21 on:** April 27, 2012, 12:24:21 AM »

Quote from: Bugflipper on April 26, 2012, 09:36:24 PM

Here's a troubleshooting page for you Dale. http://www.gmtruckhq.com/?q=node/93

BTW I run that engine and transmission in a lot of the scouts I build and have them in a few I have kept. Most of the time you will not have the actual transmission to fail. They can be used for very severe duty behind a v8. I run one behind a 392 with more torque than a lot of diesels and it has held up well. The little 4.3 doesn't really put out enough power to bother it much, not even the trip to FL with the trailer. So things should work out pretty well for you. If it were going out odds are it would be slipping instead of not wanting to go to the next gear and reverse not working.

Thanks for the link. Dale