4L60E - What's Next to Go?

[gpking]

I've got 130k miles on the clock and my trans has been a minor PITA since 84k with little gremlins appearing here and there. I'm at my wits end trying to connect the dots. What should I replace next?

Things I have replaced:
- Spacer plate
- Accumulator pistons (pinless)
- TCC valve (fixed TCC flutter)
- Manifold Pressure Switch (it set a code and would get stuck in like 2nd gear or limp mode)
- Fluid with Dexron IV (40k miles on fluid)

Ongoing Symptoms:
- Hard 1-2 shift under normal acceleration (can chirp tires on slick pavement)
- Normal firm 1-2 shift at WOT (I don't do this much though)
- Hard P-D shift (sometines it will do this so violently there is an audible bang)
- Launching in "2" seems to start in 2 or just slips horribly until it shifts to 3.
- Manual 1 and 3 behave normally.
-All downshifting is completely normal.
- All 2-3, 3-4 and TCC lockups (PWM is disabled) feel normal and consistent

More details to come. It acted very out of character today (sloppy and sluggish). I will drive with the scanner hooked up tomorrow.

 

[littleblazer]

Could it be a pump problem?

 

[16vcabman]

Probably time to take a look at the inside

 

[mrrsm]

If you have it in mind to do so.... "The 4L60E Bible" is available with quite a few offers for this Factory Manual on eBay. Between using it ....and the Complete 4L60E Multi-Part Youtube Series covering all phases of this FULL Rebuild/Repair ...both are well worth having:

https://www.ebay.com/sch/i.html?_fr...nkw=4l60e+transmission+repair+manual&_sacat=0

 

[gmcman]

Just curious, when you reinstalled the separator plate, did you get the one checkball back in the valve body before you installed the plate? This ball needs to be secured with a dab of vaseline.

 

[Chickenhawk]

Launching in 2 when placed in 2 is normal. It is how to get going smoothly if the roads are very icy, so you can cross that symptom off your list.