My friend gave this Durango to me after her employee reported that it wasn't driving past 30 mph. The fluid didn't look bad, no large metal shavings were in the pan (just pieces of screws from the below damage). Is a new accumulator piston kit worth investing in or should I just get a junkyard valve body? Also, could anything deeper in the case have caused this? I imagine some type of channel clog in the valve body caused an enormous pressur build up, leading to this.

 

What the heck??? It must have been some severe over-pressure to blow that piston out like that. I would wonder if the pressure regulator is faulty, or if some screws were simply loose, and eventually allowed that to happen.....

Is that piston bore damaged at all??

 

There were pieces of the teflon piston rings in the pan as well. I saw some videos of 545rfe teardowns where they confront this exact issue. Aparently the metal plate flexes due to the extreme pressure of the pistons. Over time this causes the screws to work loose and this is very common. If they aren't using quality steel screws, fatigue cracking in the screws could have allowed this too. One screw was broken at the head, the other was broken a little over half way down the threads, indicating that the screws had in fact broken loose. I got a valve body out of the junkyard today. I want to replace the whole thing just incase there is damage to the valve body I can't see.

 

I've driven it probably 5000 miles since finding a junkyard valve body with the white solenoid on top. I read somewhere that the white solenoid marks an upgraded solenoid which fixes some problems that the black solenoid had. It cost me a bit over $70 for the valve body and solenoid. This would have cost well over a thousand if I bought new parts online. Now I have an engine tick I can't locate. I replaced all drivers side lifters and it hasn't changed at all. Its loudest on the intake manifold when I use my stethescope.

 

Update: The transmission has been doing great after replacing the valve body and solenoid. I Just drove it from Colorado to Alabama and back. The engine tick is a leaking exhaust manifold. Some of the bolts snapped off and I need to fix them.