Installing the Last Automatic Transmission Your Hardworking Rig Will Ever Need
We feel compelled to start this report by letting you know one of the most important facts regarding installing an Allison 1000 six-speed automatic transmission in a 6.0L, 6.4L, or 7.3L Ford Power Stroke or 5.9L Cummins-motivated truck: By all means, the conversion is slick, trick, and super-bitchin’. There’s no disputing this notion. No way.
However, despite the modification being “all that” from a functional standpoint (and we’ll detail more about that as you read on), the effort—when executed the way we did it, using Ford-to-Allison conversion hardware and wiring from Custom Automatic Conversions, and a new Stage 1 six-speed gearbox and torque converter by ATS Diesel Performance—is expensive and better suited for hardworking trucks that “make money,” which ultimately offsets or fully recoups funds outlaid for the upgrade.
Sure, that’s a lot of information to process. But it honestly isn’t meant to discourage anyone from making the change, because this particular modification is definitely good. Installing an Allison gearbox is a great upgrade for anyone who has experienced the frustration brought by the failing of an E4OD, 4R100, or 5R110 Ford or a 47RE, 48RE, or 68RFE Dodge automatic transmission—especially several times.
Having experienced this breakage firsthand— twice—with the E4OD four-speed automatic in our ’95 Ford F-350, and with concerns about eventually suffering the same fate a third time, we heeded the suggestion of KC, Dave, and Mat Hemry of CA Conversions and loaded an Allison 1000 six-speed into Big White’s transmission tunnel.
An Allison, regardless of whether or not it is modified, brings strength to an area where ’95-to-’09 Ford pickups (and aforementioned Dodge rigs with 12- and 24-valve Cummins engines) suffer. Transmissions in these trucks have high failure rates when subjected to excessive heat (clutches and other frictional materials burn up) and/or severe torque loads (hard parts/ input and output shafts snap—literally).
With the ATS Diesel Performance Stage 1 LCT1000 and TripeLok torque converter we’re using, broken parts caused by any of the ways in which Big White is used (daily driving, towing, parts running, and occasional blasts down the dragstrip) become things of the past. The transmission supports 800 hp and 1,300 lb-ft of torque, and, according to ATS owner Clint Cannon, the Allison’s lockup clutch and six speeds— which include a 3.1:1 First gear and two overdrives—make it a “dream transmission for just about any diesel-powered pickup.”
While the Allison swap for diesel pickups isn’t new technology, CA Conversions has developed a comprehensive package that streamlines the process. For Big White, the system’s primary components are: a billet adapter ring and flexplate ($1,650), transmission-control module, manual-mode controller, wiring harnesses and a new gear-selector arm with tap-shift ($2,500), throttleposition- sensor kit ($295), and an application-specific mounting kit (prices for the mounting hardware range between $150 and $250). Our rig is two-wheel drive, but CA’s swap package is easily applied to four-wheel-drive trucks by using a transfer-case adapter that’s available for $1,250.
In addition to durability, believe it or not, making the switch to a six-speed also enhances a truck’s braking ability (a quality any heavy-hauling diesel-truck owner can appreciate). The torque converter’s lockup clutch and the Allison’s independent transmission controls actually keep lockup engaged as the transmission downshifts (at 1,000 rpm), which essentially allows the drivetrain to serve as a braking assist, supporting a truck’s service brakes, as well as a trailer’s stopping system, during steep-grade descents and even in panic-stop situations. The electronics unlock the converter when the transmission has downshifted to Second gear.
While overall strength and better braking more than justify making the change to an Allison 1000 (we’re actually taking Big White’s enriched stopping setup one step further by also adding Pacbrake’s engine brake for 7.3L Power Stroke–powered Fords), improved fuel economy is one of the major reasons we’ve opted for the six-speed gearbox. Yes, by adding lower overall gearing and two Overdrives, and with the truck’s 4.10 rearend gear ratio, we estimate this upgrade will improve fuel range by roughly 5 to 6 mpg in daily freeway driving conditions and will hopefully yield similar economy when we’re hooked up and towing our loaded race trailer (any improvement over the 9-mpg range with the E4OD is a welcome one).
With clientele that includes Ford, Dodge Ram, and Ram truck owners who use their rigs for such jobs as hot-shot car towing, construction, farming, and other work that taxes transmissions, Jason Loeliger and Mark Fuenzalida of Devil Mountain Diesel, expressed interest in CA’s conversion system and learning exactly what this type of inter-brand transmission swap entails.
So, in early January 2018, KJ and Mat drove Big White from Los Angeles to Devil Mountain’s facility in Walnut Creek, California, to install the ATS-built Allison and record the photo and informational data presented in this report.
Here’s a look at the internal makeup of an ATS Diesel Performance Stage 1 LCT1000 six-speed automatic transmission and TripeLok torque converter. Inside the Allison, ATS adds a modified pump for increased fluid flow and cooling and reworks the hubs, drums, shafts, and planetaries to resolve an issue these parts have with cracking in severe-use situations. Custom A- and B-trim valves are installed in the valvebody to increase hydraulic pressure and volume to the clutch packs, as are new solenoids for greater overall reliability. The channel and valvebody castings are machined to eliminate cross leaks, a critical step that confirms the valvebody’s hydraulic integrity. The zerobalance, 1,900-rpm-stall torque converter in the package features five redesigned (square-tab) clutch packs and pistons that provide better clamping on the pressure plates, ensuring separator and clutch plates are properly applied and provide even pressure. It also has a billet piston and L-trim stator and a braised impeller and turbine.
Mat installs the CA Conversions engine-to-Allison-transmission adapter ring on Big White’s 7.3L Power Stroke engine. When the ring is secured, the billet flexplate is torqued in place.
While (of course) the big transmission cooler is a natural fit in Super Duty rigs, a small amount of cutting (core support) is necessary for installing the unit in an OBS Ford.
Using Allison-swap hard parts and electronics developed by Dave and Mat Hemry of Custom Automatic Conversions in Gulf Breeze, Florida, Diesel Power Editor KJ Jones joined CA’s duo (and “Mama” KC Hemry), as well as Jason Loeliger and Mark Fuenzalida of Devil Mountain Diesel in Walnut Creek, California, to remove the E4OD four-speed from our ’95 Ford F-350 and upgrade the 7.3L Power Stroke–driven rig’s driveline using a Stage 1 LCT1000 six-speed automatic transmission and TripeLok torque converter from ATS Diesel Performance.
Driving an Allison-upgraded rig for the first time is an experience that almost immediately validates making the decision to install the six-speed transmission, especially if the unit replaces a four-speed. However, we think most newcomers to the six-speed will have to adapt to the way an Allison shifts (at 2,000 rpm for every upshift, downshifts at 1,000 rpm), its Second-gear torque-converter lockup strategy (for us, this trait was the most challenging to adapt to), and the unit’s 3.1:1 First gear.
The ATS unit installed in our rig performs well and, based on driving style/ conditions (light throttle, heavy throttle, loaded, unloaded, streets or highway, and so on), it’s clear the Allison transmissioncontrol module’s adaptive-learning feature constantly processes engine-torque data and ensures the transmission shifts into the most appropriate gears for a particular condition (ascending or descending grades, stop-and-go traffic, open freeway, local streets, and such).
Unlike the truck’s previous Ford transmissions, the Allison 1000’s internal gearing is slightly lower (see chart) and thus eliminates the need for the gearbox to downshift from Overdrive at times when the E4OD typically would (freeway passing, driving up steep hills). The Allison’s lower gearset and function basically help keep rpm and turbocharger boost pressure in their “sweet spots” at all times, making the engine more efficient from a performance standpoint, and, more so, improving fuel economy.
While Big White’s new Allison six-speed automatic transmission will always be in some type of an evaluative state, we conducted fairly extensive comparative research during the 700 round-trip miles we covered driving on U.S. Interstate 5 between Los Angeles and Devil Mountain Diesel, and going up and over both sides of the freeway’s infamous Grapevine grade (southbound is 5.5 miles at 5 and 6 percent; a confirmed truck breaker).
While the performance differences presented in the chart are dramatic…and impressive, more impressive is the effect the Allison 1000 six-speed automatic has on Big White’s fuel usage. Given the rising fuel prices in California (almost $4.00 per gallon for #2 diesel in some areas of L.A.), it’s something we really appreciate. On our outbound trip with the E4OD four-speed automatic and ECM programming set to a “Stock” tune (note that the truck’s 7.3L Power Stroke engine is upgraded with 160cc/30-percent-over injectors and a high-volume lift pump), the 8,400-pound dualie averaged 11.5 mpg over the course of 350 miles (65 mph, transmission in Fourth gear). With the new gearbox, mileage increased to 19 mpg (22 mpg/only sipped 3 gallons during one 66.4-mile stretch) for the same distance, while also cruising at 65 mph, with the transmission in Sixth gear. Since this test, fuel economy is consistent for city (14.6 mpg/typically Fourth gear) and freeway (17 to 19 mpg) driving. Towing our 11,700-pound race setup (car, golf cart, tools, and such in a 28-foot enclosed hauler), in two evaluations across the same 125-mile route, fuel economy averaged 11.4 mpg (about where mileage was with the E4OD and the truck NOT towing); markedly higher than 9 mpg with the four-speed transmission.
In addition to fuel saving, less throttle input is required to actually drive at higher speed, which keeps EGT below 800 degrees and leaves “plenty of pedal” for going faster, without working the engine hard. Also with regard to temperature, the Allison operates at consistent 140 to 155 degrees Fahrenheit, regardless of load.
After 6 months of driving with the ATS Diesel Performance Stage 1 LCT1000 six-speed automatic transmission and 1,900-rpm-stall TripeLok torque converter in Big White, we’re pleased to report the transmission continues to perform flawlessly (thanks, Allison and adaptive learning) and gives us confidence that we won’t need to call roadside assistance to come to our rescue after a gearbox failure. The Custom Automatic Conversions Allison package is tough, super efficient, and a true value, especially for trucks that work hard, and eventually will pay you back (in miles and years of trouble-free service) for your investment.
ATS DieselArvada, CO 80002
AmsoilSuperior, WI 54880
LMC TruckLenexa, KS 66219
Power Hungry Performance678-890-1110
OTC ToolsOwatonna, MN
Devil Mountain Diesel925-954-8582
Custom Automatic Conversions865-253-1133