Technically Speaking Archives - Transmission Digest
ZF 6HP26: A torque calculation error

A 2008 Lincoln Navigator with a ZF 6HP26 transmission arrives at Holcomb’s Transmissions in limp. When checked for codes, a P1719 comes up for “Inaccurate Engine Torque Signal.” The TCM receives this over the CAN, causing it to initiate failsafe. The information Ford provides for this code is vague. The Action step provided is to

Look for the little details: Three transmission repair case studies

Below are three examples of trucks that came into transmission shops, yet either did not have a transmission problem, or had a simpler issue than it originally seemed. Read on for the stories. Case study 1: Chevrolet 2500 HD Our first example features a 2006 Chevrolet 2500 HD 2WD. It has 76,257 miles on the

The 6R140 torque converter: Common fault codes and how to rebuild

There are many reasons for converter clutch slip codes to occur in vehicles equipped with the Ford 6R140 transmission. One is bore wear in the valve body with any one of the three valves related to converter clutch apply and release. Low line pressure could be another. But there is a third that is inherent

A 10L80 with a buck and bang

A 2018 Cadillac Escalade ESV AWD 6.2L using a 10L80 transmission came in to Stroli Motors barely moving forward, making a banging noise in the center of the gearbox. Reverse was good. Keith from Stroli pulled two codes from the PCM: P0300 for Random Multiple Cylinder Misfire Detected; and P175E for Shift Limiting Active. P175E

Another needle in a haystack: Locating wiring problems

Paul Loch from Certified Transmission wrote a very good and detailed article for Transmission Digest in the March 2022 issue entitled “A Needle in a Haystack – Finding and Diagnosing Intermittent Problems.” The vehicle used for this article was a 2013 Ram 3500 6.7L equipped with a 68RFE transmission. Well worth the read. ATSG encountered

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

The multi-functional Clutch 1 in Nissan’s CVT, part 1

Nissan’s Hybrid RE0F02/3H CVT transmission by Jatco (JF019E) can be found in vehicles such as the Nissan Rogue and Pathfinder as well as the Infiniti QX60. It has its traction motor located where the torque converter would normally be (as you can see in Figures 1, at the top of the page, and 2, below).

Being tuned in: The value of transmission tuning

Tuning a vehicle to optimize its performance is nothing new. This customized process is used to provide fuel efficiency and improve other driveability concerns. Tuning for torque is especially desirable by diesel owners.Those who are proficient at tuning know that the transmission will need serious upgrades to survive the increased force it will receive from

How to service the Honda 10-speed transmission

With Honda’s 10-speed front wheel drive transmission (see Figure 1, above) going into its fifth year on the roads, it’s feasible that one may show up in your shop for service. (One note: this transmission does not have a typical name; it’s simply known as “the Honda 10-speed automatic transmission” in all OEM materials.) One

Searching for the source of an unexpected transmission fluid leak

As the installer was pumping fluid into the transmission from the right side of the vehicle, he was having a difficult time getting it full.

A 3D printing solution for 948TE offset pump access

The Chrysler 948TE has an offset pump mounted in a housing that is retained by round internal snap ring that must be squeezed to release the pump from the housing (seen in Figure 1). The difficulty in doing so: there is a double tension plate located at the bottom side of the pump (Figure 2).

Having a fit with a Honda Fit

A Honda Fit utilizing a GTAA continuously variable transmission will set a DTC after reaching about 30 miles per hour. When a scan tool is used to pull the code or codes set, a U0401-68 code appears in the scan tool with the explanation of it being a TCM failure. If a tech uses the