A “Behind The Scenes” Look At What Goes Into The Making Of A TCI® High Performance Transmission
With over 40 years of experience, the name TCI® has been a symbol of engineering excellence with regards to performance torque converters and transmissions. Each drivetrain component is designed using the latest CAD software after months of heavy Research & Development and, once it is finished, is Triple Tested for product quality and reliability. And with innovative finishing techniques like the TCI® patented HDT Coating™ for cooler drivetrain operations, it should come as no surprise that TCI® has grown from a small company in rural Ashland, Mississppi to it's position today as the #1 brand in high performance transmissions and torque converters.
It’s no secret to anyone with a high performance vehicle that transmissions provide a critical link in the power transfer chain, and any hiccup in this link can spell trouble. Transmissions in this environment must rise to a new level of power transfer management, well beyond the capabilities of stock transmissions.
That’s because higher horsepower equals higher demands on transmissions, demands that stock units were never designed to handle. It stands to reason, then, that high performance people like racers, street rodders and off-roaders rely on aftermarket transmissions to do the job that stock equipment cannot do.
As the backbone of high performance power transfer, aftermarket transmissions have risen to a very high level of reliability and longevity. They are units in which enthusiasts can have confidence because they meet and exceed the challenges at every level of high performance use.
To look at how today’s aftermarket units are made, we spoke with TCI® Automotive to learn what goes into making a high performance aftermarket transmission. For over 40 years, TCI® has been the leader in aftermarket transmission building. The company employs highly dedicated production personnel and technical experts who design and build units that are the best in the industry.
TCI® engineer Kevin Winstead and master transmission builders, Bob Harrison and Paul Wilbanks, provided a unique look into what it takes to make a transmission that’s built specifically for the high performance user.
Three steps go into making a high performance transmission: breakdown, buildup, and testing. Each step requires an enormous amount of detailed work and each step is equally critical in the process. Every step depends on the other to produce a transmission that will measure up to the demands of high performance applications.
The popular TCI® 4L60E transmission is used in this story and the methods shown here follow the same systematic building process that is used in building every unit manufactured by TCI®.
Breakdown
The first step involves dismantling and inspection of each stock unit. Each transmission core is dismantled and components, such as input shafts, drums, bearing shafts, and planetary gears, go through in-depth scrutiny. Parts such as clutches, steels, seals and gaskets are discarded. Valve bodies are removed and are sent to a special division in the company for conversion to high performance models. Transmission cases are subjected to painstaking inspection making sure no flaws exist.
When the breakdown and inspection are complete, the case is ready for transformation into a high performance unit. It will be assigned an application that establishes the specific clutches, input shafts, planetary gears, etc., which will be installed.
 One of the first steps is the removal of valve bodies that are sent to
a special division to fully transform them into units adapted to high
performance requirements. |
 Clutches like the ones seen in this photo are discarded. All clutch
packs, steels, seals, or gaskets are discarded and will be replaced
with parts that are high performance rated. |
 All internal parts are removed from the case. Retained parts
are fully analyzed and inspected to determine “fitness for
use” in a high performance transmission. These parts are
triple checked to make sure they meet the high standard
requirements for a performance transmission. |
 Another vital step is the close inspection of the case to insure its
integrity for use as a high performance transmission. Virtually every
inch of the case is inspected, making sure it meets the standards for
high performance use. |
Assembly
Assembly of a transmission is a highly-detailed process and requires an immense amount of precision. Every portion of the transmission has to be right and TCI® has a detailed and painstaking system to make sure each unit is built correctly.
Before the assembly begins, a huge amount of work has taken place to measure, inspect and verify all the components. Then as the transmission is assembled, every component is again rechecked, measured and verified to validate that all elements meet and exceed the specifications for its given application.
 This photo shows the transmission case. It will be outfitted with
internal components to make it a high performance aftermarket transmission. |
 All internal systems are installed in the case. Each transmission is
systematically upgraded based on its intended application. |
 As the assembly proceeds, there are many critical tests and
measurements made. One such measurement is input shaft endplay.
As seen in this photo, dial gauges are set and endplay is measured.
A typical endplay value is .010”. |
 When all internal components are in place, the transmission is
prepared for installation of the final parts. In this photo, the valve
body circuit is visible and is the site of much of the final work in
building a performance transmission. |
 The valve body is to a transmission what a camshaft is to an engine
and as such requires a lot of testing and double checking. A hydraulic
test is the first step. This consists of checking that correct pressure
exists in the valve body circuits. This photo shows a custom-fitted
test plate that is being put into place in preparation for the pressure
and flow reading. |
 Pressure readings are taken at multiple locations as is shown in
this photo. Pressures are displayed on the pressure gauge and each
valve body circuit is checked and certified. |
The final assembly step is the placement of the transmission pan. When it is torqued in place the transmission proceeds to the dyno testing phase.
The final step is the dyno testing phase. Every unit is subjected to rigorous test cycles and multiple parameters such as parasitic drag, cooler circuit flow rate, shift quality, torque converter lockup, and line pressures are measured. Each parameter reading is matched to its specific application on a massive dyno database to verify the transmission is right.
Dyno testing is carried out on the state-of-the-art unit shown here. Every unit is taken through fully automated test cycles with
pass/fail parameters for each cycle. When the transmission has been certified, documentation is issued that will accompany every unit shipped.
Every part of the transmission is critical, but nothing will work without the valve body. As the “brain” of the transmission, they are subjected to intense building specifications and meticulous testing. Valve Bodies are analyzed and fully tested for hydraulic pressure integrity up to 300 psi, and each unit receives a TCI® Trans Scat® Valve Body Kit to make it high performance rated. The kit that’s installed depends on the specific application for which the transmission is designated.
 Valve Bodies are broken down and fully inspected. Each unit is rebuilt
using internal parts that make the unit high performance rated. Each
unit is cleaned, inspected and put into an assembly process that will
build each unit to high performance specifications. |
 All internal valve body parts have been designed to meet the exact
needs of high performance applications. Assembly of the valve
bodies is a meticulous and precise process. Each unit has to
meet rigid standards before they are certified for high
performance use. |
Every valve body has to be certified for use. Certification takes place on this valve body testing machine where every unit is mounted and
tested. Testing covers multiple factors such as circuit integrity, line pressure settings and shift timing. When all portions of the valve body have
been tested and verified the unit is certified.
TCI® Automotive
151 Industrial Drive
Ashland, MS 38603
Toll Free: 888-776-9824
TCI® - Performance Transmissions and Torque Converters 
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