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
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 – Alto introduces new front pump cover for Chrysler RFE models – Sonnax releases splined stub and sleeve kits for performance vehicles – GFX announces low-pressure drop oil cooler The
TransTec has introduced a new Stator Sleeve Tool Kit, which allows users to remove and replace worn-out GM stator sleeves, allowing them to rebuild the stator support instead of purchasing an aftermarket replacement. Each kit includes a removal tool and an instruction sheet. Each kit also comes with TransTec’s new replacement sleeves, one of
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
The kitting of transmission parts has made profitable shop operation possible. When a kit with 100 parts is necessary, a distributor has already assembled all the important components into the kit and it is typically sitting on the shelf ready to be delivered. Kitting saves time and effort for both the shop and the supplying
