GM 8L Transmission Archives - Transmission Digest
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

TransGo introduces new valve body repair kit for GM 8L series

TransGo has introduced a new valve body repair kit for GM 8L45 and 8L90 transmissions, model years 2015 and on. According to the company, the kit includes: a drop-in PR and shuttle valve line-up; a drop-in TCC regulator valve; drop-in S2, S3 and S4 regulator valves; an oversize converter feed limit valve; and an oversize

Stop/start accumulators: What you don’t know can hurt you

It’s no secret that the auto industry is making big moves these days, but while a lot is new, one thing that never changes is that the men and women servicing vehicles need to be learning almost constantly in order to do their jobs safely and effectively. Everybody knows not to touch hot exhaust parts,

Alto introduces torque converter bushing for GM transmissions

Alto has introduced a new torque converter bushing set, for GM 8L45E and 8L90E transmissions, model years 2014 and on. The part number is 224214, the OEM reference number is GM-B-7, and the dimensions are as follows: OD 1.901-in., ID 1.771-in., Height .476-in.

Diagnosing the infamous GM 8L45, 8L90 3-4 neutral

Today we are examining what we’ll call a “Twilight Zone” transmission complaint: an issue that appears out of nowhere while performing a small, insignificant repair and initially makes little sense. The 8L45 and 8L90 3-4 Neutral condition, which has been baffling many shops/techs, is one such complaint. Problem: 3-4 Shift is Neutral after installing a

Sonnax highlights end plug kit for GM 8L90, 8L45

Sonnax highlights its O-ringed end plug kit for GM 8L90 and 8L45 transmissions. According to the company, wear on various OE end plugs in GM 8L45 and 8L90 transmissions allows critical leakage at the following circuits, default override, lube flow regulation and converter lockup/release. These pressure losses impair control of clutches, effect lube flow regulation

GM 8L90 – The Other 8 Speed Automatic: Part 2

By 2014 GM released the 8L90 in the Cadillac ATS. A year later, the 8L transmission series had spread out to the Corvette and trucks such as the Silverado and Yukon. Currently, GM offers two models of eight-speed transmissions, the light-duty 8L45 and heavy-duty 8L90. When GM developed the 6L80/6L90 transmission series, they were loosely based upon the ZF 6HP family of transmissions. The 8L90 also has a ZF thumbprint on it, though somewhat less than the previous six speeds. One welcomed departure from ZF was the absence of an internal TCM in the GM units.