Transmission slips if I shut truck off and restart it will do fine for a few seconds then slip again

ANSWER : Hi there, thanks for writing in.

The reason is starts slipping at 30 is this is where it needs to change to second gear or third gear. The problem is most likely the servo piston for the second gear engagement is binding in the transmission housing due to a worn housing. The fix is to overhaul the transmission and have a sleeve put into the housing during the overhaul with an oversize servo kit. The only other fix would be to replace the transmission with a new or rebuilt unit. The reason it works after turning the car off and back on is because it sets a fault for itself and goes into limp mode, and turning it off will erase that fault until its seen again, at which point it will go into limp mode again. You can have this diagnosis verified by a qualified technician, such as one from YourMechanic, who can then provide you with a suggested repair plan.

ANSWER : Hello. From what you describe, it would appear that your transmission is beginning to slip. This can be caused by many things. The first thing I would do is check the vehicle’s transmission. Automatic transmission use fluid pressure to operate, and will have all sorts of issues if the fluid is low or dirty. If the fluid checks out, I would then move on to looking at the transmission itself. It may be possible that one of the components, such as a sensor or solenoid may be going out and causing your issue. It may also be possible that the transmission is simply worn out and can no longer hold the engine torque, perhaps due to a worn clutch pack, valve body, or torque converter. In these cases of removal and overhaul of the transmission is required. You may be able to continue driving the vehicle, however, because it may cause the symptoms to worsen over time if the issue is not quickly addressed.

ANSWER : The transmission in your truck has the updated 4L60 series with a heavier duty forward gears and thrust bearings so your transmission problem is most likely the torque converter or front pump failure. The clutch materials in an automatic transmission are very thin and if you have had slipping for over 10k miles you may have caused even more internal damage to other internal components. You will most likely need to have the transmission replaced or overhauled with a new torque converter. All the lines will need to be flushed out also to keep from contaminating the new or rebuilt transmission. Replacing the transmission with a remanufactured or a good used transmission with a warranty would be the recommendation I would give, since the truck is under 10 years old and has low mileage. Have the transmission system thoroughly checked by a certified mechanic, such as one with YourMechanic, before condemning it and before any replacements or repairs are done.

ANSWER : This sounds like a faulty speed sensor problem. Most cars have two speed sensors (one monitors input shaft and one monitors output shaft) which tell the computer what the gear ratio is of the transmission while in use. If either of these are not working properly, they will cause the computer to shut the car off for safety reasons. I would suggest having an expert from YourMechanic come to your home to diagnose your stalling issuee and help you repair it.

ANSWER : I agree with the other mechanic. If the fluid looks dirty then this means the transmission was not serviced for a long time and if you service it then the new fluid will wash out all the clutch material that is being held together by the old fluid. You would be taking a big chance that the transmission will start slipping within a week after you service it.

A 75-point safety inspection is a good idea after long-term storage, and a qualified technician from YourMechanic can perform this for you at your home or office.

ANSWER : Hi there. The 4l60e transmission could have two things wrong with it. Either the park arm is not disengaging inside the transmission making the transmission load up but not rotate the drive shaft or the transmission is low on oil. Check the oil on the transmission dip stick and see what the level is. The level must be checked with the engine running. If the oil level is at the full mark, then it is possible that the torque converter may have damaged the pump.

Remove a cooler line and put it into a bucket, and for a brief moment start up the engine and shut it off. If oil sprays out of the cooler line, then the pump is producing pressure. However, if no oil comes out of the cool line, then the pump is not working.

If you need further assistance troubleshooting your transmission, then I recommend having the transmission problem diagnosed by a local expert, such as one from YourMechanic. You will be be able to make a better decision about the car after finding out exactly what’s wrong with it.

ANSWER : After some testing done to verify the EGR valve flow to see if the valve is intermittently sticking open causing the stall. This can be done using a scanner with the capability to open and close the EGR valve and monitor the DPFE sensor at the same time. There is a technical service bulletin 05-4-17 to replace the EGR valve if the valve sticks open. The computer system should be retested to verify the proper operation of the EGR valve and DPFE sensor. Once the EGR valve is replaced and system is verified the EGR system is working correctly without the EGR sticking open anymore then have a certified technician, like one from YourMechanic, scan the computer to clear any codes. Once codes are cleared a road test should be done on the car to verify the repairs.

ANSWER : The problem sounds like you have flat spots on the tires in the rear when the tow truck operator dragged and pushed the truck with the transmission locked. I would recommend having a vehicle safety inspection to see if there is tire damage or other possible damage done by the tow truck. Have a mechanic from YourMechanic come and do the inspection and check the problems for you.