Below are the diagrams for vacuum testing GM 8L90 transmissions. Note: OE valves are shown in rest position and should be tested in rest position unless otherwise indicated. Test locations are pointed to with an arrow. Springs are not shown for visual clarity. A low vacuum reading indicates wear. For specific vacuum test information, refer to additional information available at www.sonnax.com.
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The effectiveness in diagnosing automatic transmission malfunctions is an art form. Although there are similarities among the wide varieties of transmissions on the road, each transmission has its own peculiarities. Aside from having mechanical, hydraulic, and electrical hardware systems to contend with, software/programming issues and various vehicle platforms make diagnostics much more difficult. Using scopes provides
The effectiveness in diagnosing automatic transmission malfunctions is an art form. Although there are similarities among the wide varieties of transmissions on the road, each transmission has its own peculiarities. Aside from having mechanical, hydraulic, and electrical hardware systems to contend with, software/programming issues and various vehicle platforms make diagnostics much more difficult.
The 6T40 was introduced in 2008 for General Motors front-wheel-drive cars in the Chevrolet Malibu and has gone through several changes throughout its three generations, specifically in the pump area. The 6T40 is closely related to the more lightweight 6T30 and the heavier duty 6T45 and 6T50. Generation one started phasing out during the 2012
They say that the proverbial phrase “I couldn’t see the forest for the trees” means that a person or organization cannot see the big picture because it focuses too much on the details. Related Articles – TASC Force Tips: Diagnosing 8L45 & 8L90 Shift Complaints – TASC Force Tips: Hydraulics Fundamentals: Check Valves – Shift
The Honda six-speed transmission has been on the bench of many specialty shops for one reason or another (figure 1). But, for those of you who have yet to lay your hands on one, mounted on the upper side of the unit is one of the largest, if not the largest solenoid and pressure switch
The 4L60E transmission platform has been in service from 1993-2015; that’s 22 years. It amazes me when a transmission that has been around for this long can throw a new twist on a common problem and blindside you. Let us have a look at the systems and potential problems in a 4L60E that can cause
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
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. Related Articles – Podcast: Talking CVTs with Transtar, part 1 – Back to square one: When a transmission replacement doesn’t fix the problem – Shift pointers:
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
American Powertrain now offers a Tremec 4×2 TR-4050 five-speed Pro-Fit HD manual transmission kit designed for 1988-98 Chevy/GMC OBS light- and medium-duty trucks. Related Articles – Shop Boss adds new user interface to its shop management software – ATI introduces flexplate and bell kit for Ford 7.3L Godzilla engines with GM transmission – Alto adds
