Cause of transmission front pump to fail?

[jgZ71]

New here so hello everyone!

So I bought a 2004 Tahoe 4x4 (5.3L with 4l60e) with a bad transmission (no 3rd or 4th). I took it out and bought a rebuilt one off of this guy who claims to be a transmission specialist. Well after 4,000 miles when I was driving down the highway the pump went out. Lost all gears. I called the guy and he said he would fix it for free under warranty but said the cause was the TPS. I haven't gotten the tranny back yet but I don't want to put it back in not knowing what caused it. Could a TPS really cause it to fail?? he said the TPS made the pressure too high. But that's an expensive part to replace not knowing for sure if that's bad. And the engine runs fine. No check engine light either. So what could cause that to go bad? And when I installed the transmission the torque converter came right up to the flex plat and I didn't see any gaps that would cause the torque converter to slide too far our of the tranny. When I installed the TC I heard and felt it slip down into place so I don't think that had anything to do with it. I just have a hard time believing the cause was the TPS.

Thanks in advance for your help!

 

[rockola1971]

TPS? Throttle Position Sensor? I dont think so.

 

[sumo]

Converter not installed properly could do that. Not enough trans fluid. Has the entire trans been rebuilt? Hopefully he didn’t try to reuse A lot of the time when this happens is due to installation error

 

[bottomline2000]

When u felt and heard the converter slide down did it actually drop down to the flex plate. You shouldn't hear anything. The proper install would be to measure the gap from the converter pads to the flex plate with converter fully seated in the trans. This will ensure you have a proper gap and down pull the converter too far off the pump. Could be improper pump install. Tps affect the trans pressure seems like a stretch.

Sent from my SAMSUNG-SM-T377A using Tapatalk

 

[M1Gunner]

The tps sensor will NOT cause the pump to fail. The pump works off directly off engine rpm and it’s the electronic pressure control solenoid that regulates the transmission line pressure. Will the PCM work with TCM and use the tps sensor to help designate shift points, absolutely. But the tps will NOT directly cause the transmission or it’s fluid pump to fail. If the tps fails and the vehicle enters limp mode then your stuck with 2nd and reverse gears only.

The tangs on the end of the converter could be potentially damaged IF the the converter wasn’t fully seated in the transmission. Typically you’ll notice two drops or “clunks” when you install it. But I don’t believe that to be the case since you drove it 4K miles...

 

[M1Gunner]

I will say this though, recently a friend of a friend dropped his Dodge Ram off to me and said it was shifting extremely harsh and at times not wanting to properly downshift. He took it to Tires plus and was quoted a new transmission. After talking to our mutual friend he dropped it off to me for a second opinion and that thing was in fact bucking to hell and back. After hooking up my Maximus 2.0 and looking through data found that the tps sensor was sending was erroneous readings. I back probed the tps to see if the data was correct and the tps was off but not throwing any codes. Picked up and installed a new tps and you can’t even tell when the truck shifts now.

Long story short the tps will effect the transmission 100%. But it has NOTHING to do directly with the tran fluid pump or line pressure. Your mechanic is unfortunately mistaken.