4L60E Front pump failure.

[A-Aron]

Okay.. Swapped in a I6 trailblazer torque converter into my 2000 Silverado. Lost fluid 2 times cause of the line blowing off my 40k cooler, stopped both times immediately and refilled to appropriate level. Drove to my tuner to have some adjustments done for mods I added ( long tubes, ported TB) Drove great, shifted fine even did a few 0-60 pulls with no issues. Drove for around a week after and truck just stop pulling in the pick up line at my daughter's school. Pulled transmission and tore front pump down to fine this damage (see photos). Do you guys think this could be a install problem of the converter or a increase in line pressure done by the shift kit or tunner or both?

 

[Marky Dissod]

Drove to my tuner to have some adjustments done for mods I added (long tubes,
ported TB)

Why did you get a ported throttle body? What other mods did you do to support this?
Also, you're supposed to pick one -

... increase in line pressure done by the shift kit, or tuner, or both?

- or the other, not both.
If you failed to inform the tuner that you installed a shift kit, before he turned up the line pressures, he can't protect you from yself.

 

[A-Aron]

Ported TB was just for throttle response and idle. It's a 5.3 bored .30 over with 4.8 flat top pistons with a truck Norris cam upgraded Michigan motorsports valve train. Less than 3k miles on engine. Don't see why that was important only dynoed 315 HP and 320 tq on motor. I gap the rings for 150 nitrous shot top ring at .022 and matched the second ring at .022. like the post said truck drove fine for about 4 days after torque converter swap then 3 days post tune adjustment pump gave up the ghost. I am not looking to blame anyone, I am just trying to learn from any mistakes. I built the engine so I know it's good to go, the trans after opening it up seems to have been rebuilt before( REMEMBER THE TRUCK HAS 289000 MILES) I REBUILT THE REAR END WITH A Yukon LSD AND 4:11 GEARS AND UPGRADED THE CLUTCHES INSIDE THE DIF., SO I KNOW That's GOOD TO GO. the shift kit was installed by me when the truck was a v6.... Same tuner tuned line pressure and shift points post rear end rebuild and tire size change( 17 to 20). I am just wondering if the damage was caused by loss of fluid when ever the line blew off, or did it over heat the pump causing it to crack then over those 3 days give out??? Just thought I would get your guys thoughts

 

[stutaeng]

Torque converter not seated completely in can destroy a pump, so yes, likely that could have been the issue.

There's a belief that you should hear "3 clunks" when installing it, but I've never followed that because you sometimes you won't hear that depending on the spline alignment.

What I do is measure the torque converter pads from the bellhousing using a straightedge.