4l60e stock tune

[ytry]

Hello all thanks for you time. I have a funny thing going on maybe someone can help me with.. I had to have my trans rebuilt and they said it blew a check ball through a plate and broke the drum.. Now im no trany guy but could a tune do this? would anyone have a stock trany tune i can look at? they are building it again this is twice it has happened and I would rather it didnt happen again.. any help would be great... thanks

[joecar]

That can happen with the thin spacer plate if the PCS solenoid was adjusted to increase it's physical maximum pressure limit (it has a screw which can be turned to increase it's pressure... the PCM will never know that this was done)... this causes the PCS solenoid to regulate a higher maximum "Torque Signal" pressure than the PCM thinks it is commanding, and this in turn "assists" the Pressure Regulator to increase pressure above what the trans. was designed for... add the stiffer Presure Regulator spring from a shift kit, and you have even more pressure;

A tune can't do that because a tune can't increase Torque Signal pressure beyond the physical maximum limit of the PCS solenoid.

With the thin spacer plate, the excess pressure pushes that particular ball into the plate, enlarging the hole (the ball usually gets stuck in the hole, or may push thru)... there is a thicker spacer plate with a smaller hole to prevent this from happening, they need to install this thicker plate;

they also need to install an unmodified PCS solenoid (because you can't tell how many turns the screw was adjusted on a modified one).

That ball blocks a larger hole so that the fluid has to pass thru a smaller hole next to the larger hole (both holes feed the same circuit)... the effect being to ramp up the application of pressure to the apply component (i.e. the smaller hole initially restricts both flow and pressure, but once the circuit is filled (flow now stops because circuit is full), the pressure continues to ramp up to it's final level).

[joecar]

See check ball #8 (item 1c)...





See description of ball #8...

[joecar]

If that checkball is stuck in the hole (pushed thru), then when that circuit exhausts, the ball is impeding the fluid draining back out thru the circuit, so the release of the servo will be slowed down... the band will drag and will get worn.

[ytry]

wow that is a huge help! thanks so much!