Slips in drive and reverse but not 1 or 2

[greasemanicure]

It seems like ages ago but it was only 85000 miles ago that I was helped with a tranny problem on our 96ExOHV4Wd. Then I did the valve body and then swapped out the tranny. At that time we lost reverse first and then everything. Now, taking off in drive or reverse is really mushy with major slipping. No slipping however in 1 or 2. The tranny was low on fluid and topping that up improved things but still far from right.

Is this a band adjustment issue or does it sound more like solenoids or something else? In the mean time I will see if I can find a leak where about a quart of fluid went since I last checked it about four weeks ago.

 

[greasemanicure]

More info

The slipping taking off in drive seems to go away if I turn off OD.

 

[greasemanicure]

More info 2

Pulled codes. Expected the one related to the shorted O2 sensor wire. New ones due to a pulled vacuum line on the EGR. No tranny related codes as I got the last time. No clear evidence of a pan or line leak.

I intend to drop the pan and do a fluid and filter change ASAP.

 

[greasemanicure]

Pressure Gauge parts FYI

I went to Northern Tool and got the following parts to measure the tranny pressure.

1 - 0-300 PSI gauge #53702 $12.99
1 - 3/8X120" 4kpsi hose #459315 $27.99
2 - 1/4X3/8 M-F (A10) coupler #359425 $ 4.98
1 - 1/4X1/4 F-F(E15) coupler #359357 $ 2.99

Found the thread on measuring pressures on BrooklynBay's favorites thread. Thanks!

Pressures to follow.

 

[greasemanicure]

Pressure Readings

Monsoons are over in NC for now. Took a test drive with the pressure gauge connected to the main port on the drivers side. Here is what I got.
Idle cold in park 90
Fast idle (2k) 100
Idle warm 75-80
Fast idle (2k) 90
Idle OD 85
Idle OD off 90
Idle 2 85
Idle 1 90
Idle Reverse 150
WOT OD 95
WOT OD off 240 (why the difference he wonders)
Driving off in OD has much slip with pressure 100-200. Driving off with OD off has no/much less slip and pressure 90-100
Moving in reverse hot or cold has major slip and pressure 150+ When I say "major slip" think novice driving stick and racing engine to avoid stalling and taking off slowly.
When I got back the idle pressure was 110-120 and unsteady. The OD/OFF light began flashing along the way and dumped a code P0756 Performance Shift Solenoid B Circuit or stuck off. Search suggested that this would indicate a 3rd gear issue which is either not my problem or is masked by the other more glaring issues.

The ATSG also describes a stall test, watching RPM with WOT to peak out. OD and reverse fail with high or no stall point. Drive, 2 and 1 fall in the normal range of around 2400 RPM. The diagnostic table on page 26 does not give an option for OD and R failures but ones for OD and "R only". Would the Low/Reverse servo have anything to do with my symptoms?

I plan to reroute the "plumbing" and measure pressures at the EPC port tomorrow or on the weekend. The ATSG gives pressure norms for both the line and EPC test ports on page 24 of the 4R44E document linked elsewhere.

This may remind you of something you have already encountered and fixed.

Thanks!
Joe

 

[yob_yeknom]

subscribing

I also have a similar problem (I've been posting about it here) so I'd like to follow this thread also.