I keep breaking pumps in my 4l60 the tabs break off. I have broken ten pumps now. I have an 03 sierra with a 6.0 and a turbo on it I am putting about 550 to the wheels I run a tci converter, and the pumps always seem to real when just cruising not under a hard acceleration. Any ideas

 

10 pumps. Holy crap. I would have given up and gone 4l80 by now.

 

I'm no expert here, but have you put a pressure gauge on your transmission to see how high the pressures are?

 

I would be more concerned with the alignment of the converter to the pump, pump spacing etc... And yeah it would be useful to have pressure readings.

10 pumps is 10 too many. I have not heard of a combination that eats pumps like this before. How long has that converter been in there?

g

 

The converter has been in for a while now. I had the same problem with the trailblazer converter I had in it previously. If it was an alignment issue u would think I'd have seal leaks

 

I find it interesting that two different converters have been in it and it's suffered the same fate. And the alignment issue I am thinking about will not cause leaks. I'm thinking that either the engine has too much crankshaft thrust which can force the converter into the pump, or the converter is simply not spaced away from the pump properly.

Which flexplate are you running and how much space is there between the flexplate and the converter pads when the converter is unbolted and bottomed out into the pump?

Tell us what mods you have to your transmission. I'm curious to know what pumps you're running. Who is doing the install, who built the pumps etc... I'm sure we can figure this out.

g

 

sounds like a converter depth/flexplate issue possibly to me. I'd start measuring.

 

Well let's see. I didn't mention this has happened before and after I changed to a 6.0 liter. The trans is a stage 2 performabuilt. Since that warranty ran out I have built it myself. I am an ase master tech and work for a Chevy dealer as a tech for a living so I have done all the work myself. They are stock pumps. Stock flexplate and about 3/16 inch between flexplate and converter. Oh and this also happened before the pwrformabuilt trans

 

Are you using the same pump just rebuilding it? If so maybe something wrong with pump.

 

Same question here. Also how are the dowel pin holes in the bell housing? Being that this happened with the original trans and now with the PB unit I would be questioning the bell. Have you changed the flex plate in this truck?