4l60e

[IJ.]

This might be one of the reasons why GM/Hydra-Matic removed the 3-2 control solenoid in the later 4L65E's.

Interesting, wonder how they achieve a downshift?

[joecar]

The 3-2 control solenoid does not command a shift...

but rather it controls the fluid exhaust rate from the 3rd accumulator which controls the rate at which the band is applied when downshifting into 2nd gear.

[IJ.]

The 3-2 control solenoid does not command a shift...

but rather it controls the fluid exhaust rate from the 3rd accumulator which controls the rate at which the band is applied when downshifting into 2nd gear.

Got ya, how is it controlled in a late 65?

I only have flow charts for 60 and early 65.

Can't use the 65/70 Valve body on a 60... doh

[joecar]

The later 4L65E just lets the 3rd accum fluid exit without restricting it (is my understanding).

With the 4L60E the PCM restricts the 3rd accum fluid at higher rpm by either firing the 3-2 solenoid (later 4L60E) or by modulating (PWM) it (earlier 4L60E) to control downshift feel (so they say).

[IJ.]

The later 4L65E just lets the 3rd accum fluid exit without restricting it (is my understanding).

With the 4L60E the PCM restricts the 3rd accum fluid at higher rpm by either firing the 3-2 solenoid (later 4L60E) or by modulating (PWM) it (earlier 4L60E) to control downshift feel (so they say).

Hence the self destruct on kickdown... :(

Thanks Joe, I did some research yesterday, looks like there's no "easy" late model retrofit either as they made a couple of changes at the same time, might have a look at a spare Solenoid and see if there's a way to derestrict it.

[lbheart]

how do you telll if its engaged on the pump?

i put the transmission in and filled all the way up with fliud and left the cooler lines undone to flush them.

went to turn it over and it was hard to turn over like it was aliitle bit tight or seized. got it started but no fluid flowed from the cooler lines and no drive when i put it in gear like i have put it back together with out engaging the torgue converter in the pump but i didn't thnk the torgue converter would go all the way home in the bellhousing unless it was engaged in the pump.

[lbheart]

really dont wanna take it all apart again.
fuck it

[IJ.]

There are 3x splines you need to engage, I hold it by the TC snout and spin/push it until the TC is almost touching the pump, if you've bolted it up not engaged there's a chance you've damaged the pump or the TC... :(

[lbheart]

fuck it
when i get it apart what do i look for to see if i have damaged anything which i dare say i have i did it in a rush last night

[IJ.]

Check the end of the converter where the drive dogs engage, if they're marked up at all I'd pull the pump and inspect it as it's cast iron and have been known to fail in use they're not that strong.. :(