Transmission swap – 1999 Chevrolet Silverado

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 : My research indicates that only the Allison 1000 transmission had 5 speeds offered in that model year truck. If the Allison 1000 for your 4L60E is what you’re considering, the benefit is likely small (more intermediate speeds, yes), for the considerable conversion headaches (getting the engine and transmission computers to talk to each other, custom driveshaft and flanges, possible bodywork – Allison is bigger case), etc. You may have other reasons for doing this, but most of the truck communities are not overwhelming on this swap. If you do go through with the swap and need assistance, consider YourMechanic, as one of our mobile technicians can come to your location to diagnose and service your car.

ANSWER : The 4L60-E should be interchangeable from vehicle to vehicle so this is more likely an electrical issue. Fuses to the powertrain and transfer case shift module need to be checked and any faults should be read out. Also, inspect the wiring to ensure the wiring harnesses have not been pinched. You may want to enlist the help of a mechanic, such as one from YourMechanic, who can survey the faults to diagnose your gear shifting issue.

ANSWER : Hi There,
This is a known issue in this generation Ford Focus and some Fiestas with the "Power Shift" transmission and there have been numerous recalls and lawsuits. Although, it is would be difficult to determine how much longer your transmission will last given the fact that you have many new parts, I would not recommend junking the car as it may still provide some valuable life left for you. I would recommend taking it to the dealer to see if these parts may be covered under the recall.

ANSWER : Hello – your intuition is correct. The ring and pinion gear are severely worn, and will need to be replaced (w/all new ring and pinion bearings) to eliminate the "noise under load" you notice. Setting up a ring & pinion gearset and bearings requires specialized skills and equipment. Check with your local auto machine shop for reliable references and sources for this task.

ANSWER : This would depend on what the manufacturer recommends. Many manual transmissions do take automatic transmission fluid. If your transmission has ATF in it, it is very likely that it is supposed to have that in there. If not, it is likely that the transmission would not function properly with the wrong fluid. Many manual transmissions will also take engine oil as a lubricant. The best way to know for sure is to check your owner’s manual or call your local General Motors dealership to inquire.

ANSWER : Hi There,
This may be an issue related to the communication of the PCM and the TCM (Transmission control module). As you may know, the TCM relies on the PCM to transmit information related to RPM’s, which the TCM then uses to determine when to direct the transmission to shift. The transmission control module has various sensors such as vehicle speed sensors, wheel speed sensors, throttle position sensors, turbine speed sensor, and transmission fluid temperature sensors that all direct information to it in order for it to perform it’s function. Other functions controlled by the TCM are components such as a kick down switch, traction control system, and cruise control module. Any of these may also affect the way the transmission control module performs and controls the transmission and the shifting of your vehicle. I would suggest having a professional from Your Mechanic come to your location to properly diagnose your transmission problem.

ANSWER : Hi there. In most cases when you overfill the transmission fluid it can cause excessive foaming of the fluid or possible internal component failure due to excessive pressure inside the hydraulic lines. Sensors like the speed sensors however are rarely impacted by this situation. However, in regards to the possibility of probability of this; I would say perhaps a 10% chance.