Watch out for high pressure in GM 8L45, 8L90 valve bodies
Hey now! Oh boy, do I have a fun failure to share with you and warn you about today! Have you encountered a crack in the worm tracks in your GM 8L45 and 8L90 valve bodies (as seen in Figure 1, above)? Sonnax has, and wow, is it frustrating. Once cracked, there is no way
Shift of the shaft: Diagnosing Chrysler 48RE manual shaft issues
The TorqueFlite transmission has been around since mid-to-late 1950s. There have been many changes surrounding the manual shaft and rooster comb through the years. This transmission shaft controls the position of the manual valve that directs oil for the gear ranges, but it also is used for a Reverse light control as well as Park/Neutral
Diagnosing Ford 10R60, 10R80 and 10R140 series speed sensor issues
Ford 10-speed 10R series transmissions utilize four two-wire, Hall-effect sensors — TSS, ISSA, ISSB and OSS — for providing speed signals to PCM or TCM. They are supplied nine volts by a PCM or TCM and assist in the control of clutch apply/release timing that is used in determining shift quality, including TCC. Here are
Easy TH400, 4L80-E reverse servo setup: Craft your own tool
While not as sensitive as some shifting bands, the Reverse band adjustment on a TH400 or 4L80-E transmission is critical, and failure to get it right has tripped up even the best builders. There is nothing worse than getting the transmission installed, putting it in Reverse and then not going anywhere or having no engine
Understanding lube flow control valves in Toyota/Lexus UA/UB80 transmissions
The Toyota/Lexus UA80 and UB80 transmissions first came out in 2017 in Highlanders and Siennas. The UA80 is used in V6 applications, and the UB80 is paired with four-cylinder versions. They have been called Toyota New Global Architecture type transmissions, and alternately referred to as the “Direct Shift 8AT” eight-speed automatic transmission. This transmission was
Toyota/Lexus UA/UB series: Critical wear areas and vacuum test locations
Sonnax has provided the following guide on critical wear areas and vacuum test locations for the Toyota/Lexus UA and UB lines of transmissions. Technicians working on these models should find this guide helpful. Read more stories from our TASC Force Tips series here.
Tips and tricks for Chrysler switch valve plug testing
As technicians, we are often faced with build issues that can sometimes be frustrating at first. But with a little ingenuity, these frustrations can be turned around and made simple. In 1989, Dodge came out with the first fully hydraulic electronic-solenoid shifting transmission, the A604 (no shift valves), which later became the 41TE. Originally, there
Jatco/Nissan JF011E critical wear areas and vacuum test locations
Sonnax has provided the following guide on critical wear areas and vacuum test locations for the Jatco/Nissan JF011E. Technicians working on these models should find this guide helpful. (Ed. Note: This is an extended version of the guide found in our September issue, with three additional pages).
Tips for success with the GM transmission fast learn process
This article is about failure, something we all experience from time to time. If you are attempting to perform a fast learn process on a GM eight-, nine-, or 10-speed transmission, you may have that temporary feeling of failure, as this process can bring on frustration quickly. Let’s talk about what the fast learn process
Troubleshooting RFE overdrive clutch failure: Three key areas to check
Fighting overdrive failure in Chrysler RFE transmissions can be a frustrating task. You build the unit, and a week later, it’s back with the overdrive clutches burned up again. It happens with every one of them, from the 45RFE, 545RFE and 65RFE to the 66RFE and 68RFE. You have replaced the valve body and double-checked
Diagnostic tips for the Ford 6F35
We have all experienced repairs that seem to “go down the rabbit hole,” as we call it. Our subject today is one such issue: a Ford 6F35 transmission with codes P073D or P177F after repair and a complaint of trying to go into Reverse while in Neutral, or a bind in Forward when cold. This
Diagnosing AS68RC intermittent pressure switch/linear solenoid performance codes
Intermittent pressure switch codes on vehicles with the Aisin Seiki AS68RC transmission have been very difficult to nail down to one specific cause. The two most common pressure switch codes for this transmission are P0746 clutch pressure control solenoid A or linear solenoid A performance or “Stuck Off,” which also includes pressure switch 1 mechanical
