Ford 6R140 no engagement cold - Transmission Digest

Ford 6R140 no engagement cold

The complaint

A 2015 Ford F-250 equipped with the 6R140W transmission has just been overhauled. Shortly afterward, the transmission has begun to develop forward and reverse engagement problems when the unit is cold. As it warms up towards operating temperature, the engagement problems diminish and do not return until the next cooldown period. Trouble codes P0722 “Output Shaft Speed Sensor No Signal” and U0422 “Invalid Data Received From Body Control Module” are set.

The cause

An undersized o-ring seal on the new filter neck (refer to Figure 1 above), is causing pump cavitation. The pressure gauge connected to the line pressure port indicates zero pressure (see Figure 2), which would explain the no engagement complaint.

Tech-Talk-January-Figure-6
Figure 2.

Even with the case connector disconnected, the gauge still indicated zero pressure. As the transmission warms up the o-ring seal swells enough to allow fluid to be picked up, at which point the pressure gauge jumps up to the correct line pressure as seen in Figure 3.

Tech-Talk-January-Figure-7
Figure 3.

Note: This may have been mistaken for a drain back problem, but the dipstick did not indicate an over-full condition when the transmission was cold.

The correction

Replacement of the filter with a good o-ring seal eliminated the engagement problem entirely. The above listed trouble codes were cleared and did not return, as those code definitions were falsely generated.

Read more articles in our Transmission Tech/Talk series here.

You May Also Like

Chrysler ZF8 generations 1 and 2 identification guide

In 2019, some Chrysler/Ram/Jeep applications that utilize the ZF8HP transmission moved to a second-generation unit with a new designation and numerous changes for better performance and durability. Gen. 1 units are classified as 8HP45, 8HP70 and 8HP90; while Gen. 2 are classified as 8HP50, 8HP75 and 8HP95. Internally, the Gen. 2 transmission had numerous hard

Tasc-Tip-April-Figure-1-Gen.-1-'B'-Brake-Components-1400

In 2019, some Chrysler/Ram/Jeep applications that utilize the ZF8HP transmission moved to a second-generation unit with a new designation and numerous changes for better performance and durability. Gen. 1 units are classified as 8HP45, 8HP70 and 8HP90; while Gen. 2 are classified as 8HP50, 8HP75 and 8HP95. Internally, the Gen. 2 transmission had numerous hard part changes due to a change in gear ratios. Controls also went through numerous changes, as one of the clutch/brake-related circuits was eliminated.

When a transmission problem isn’t a transmission problem

Let’s take a look at three examples of times when a car’s issue seems to be a transmission problem, but a closer look reveals another culprit. Related Articles – Photo gallery: TCRA Annual Meeting 2023 – California’s Rohnert Park Transmissions is a multi-generational success story – A part for every need: Hard parts supplier listing

Shift-Pointers-April-Figure-3-1400
Breaking parts: Pressure regulator valve and bore blues

One of our ATSG members, Bob at Trans Tek, recently shared with us an experience he encountered with a 2011 GMC 3500 Mini School Bus with a Duramax diesel engine in front of a 6L90 transmission. It came in to the shop slipping, along with having no second or sixth gear. After the transmission was

Tech-Speak-April-Figure-1-1400
Transmission fluid hydraulics

To understand why using the correct transmission fluid is necessary, you first have to know how the transmission fluid flows inside an automatic transmission. Related Articles – GM 6L series no-movement conditions: Analysis and repair tips – 2023 State of the Powertrain Industry – Powertrain industry directory and buyer’s guide 2023 Fluid paths The journey

Transmission-Fluid-Hydraulics-and-Shifting
TCM trouble and the importance of being certain about parts replacement

It’s a tale as old as time. A vehicle comes in and, despite having been recently repaired by another shop, the vehicle owner’s concern is still present. In the case of this story, the vehicle came from a local shop we work closely with. The truck in question is a 66,000-mile 2006 Chevrolet Silverado 2500

RR-Tech-March-FIG-1-1400

Other Posts

Critical wear areas and vacuum test locations: GM 10L and Ford 10R series

Sonnax has provided the following guide on critical wear areas and vacuum test locations for the GM 10L series and the Ford 10R series. Technicans working on these models should find the following four pages helpful. Related Articles – Scope testing the Ford 10R80 – Announcing the winners of the Top 20 Products and Tools

02feb23_TASC-feature-1400
Scope testing the Ford 10R80

Recently, we at Certified Transmission had a chance to do some work with the Ford 10R80. We have easy access to test vehicles since our owner also owns a used car dealership. For our R&D testing we used a 2019 F-150 equipped with a 5.0L engine and the 10R80 transmission. I got to play around

RRfeature1400
Georend Transmission adds Ford 6R140 transmission pan kit

Georend Transmission has announced a new Ford 6R140 transmission pan kit. Related Articles – American Powertrain offers Tremec TR-4050 kit for Chevy/GMC trucks – GFX announces low-pressure drop oil cooler – TransTec introduces stator sleeve tool kit Features and benefits highlighted by the company include the following:

6r140-pan-kit-product-image-600
Shift pointers: A 4T65-E that wants to move in Park and Neutral

When conducting ATSG seminars, as we are usually covering a specific piece of tech, we’ll often tell attendees that if they put this together wrong, they should let us know what happens. Just recently, Ricky Hodgkinson from AACTION Transmission did just that. He was kind enough to share an incident he recently had with a

ebulletin-feb-feature-1400