The Makings Of A Bulletproof Ford 4R100 Transmission

Rock Solid Automatic

Mike McGlothlin
May 1, 2010
Photographers: Mike McGlothlin
The release of Ford's Super Duty in 1999 kick-started an explosion of aftermarket performance parts for the revamped 7.3L Power Stroke. But dieselheads quickly found the weak link: the 4R100 transmission. Much like the E4OD (offered behind Power Strokes from '941/2 to '97), with just a hot performance tune and a heavy right foot, the stock slushbox could be destroyed rather easily.
Photo 2/18
One shop that's been specializing in 4R100s (and any Ford transmission, for that matter) since the beginning of diesel truck performance is John Wood Automotive. Over the last decade and a half, owner John Wood has seen all kinds of transmission failures, and each bulletproof transmission he puts together today is the result of extensive, hands-on research and development. With a full line of transmissions for Ford trucks, he's built a reputation of doing the little things that make an automatic durable, reliable, efficient, smooth shifting, and according to his customers-indestructible.
Over the winter we got our hands on an '00 Ford F-250 Super Duty with an ailing factory automatic transmission and took it to Wood. Once there, we were able to see his expertise in action, as he transformed the stock, burnt-up 4R100 into a rock-solid, tow- and track-ready unit.
Photo 3/18   |   The first signs of internal damage were visible after the 4R100's transmission pan was removed. A considerable amount of metal was present in the bottom of the pan, and the magnetic drain plug had accumulated a lot of debris as well (arrow). John Wood told us that this was probably due to the clutch plates breaking down and coming apart.
Affordably Priced
Thanks to longtime engineering friend John Corrao (who has offered an array of knowledge over the years), Wood is able to build a transmission unlike anything else offered on the diesel truck market. Wood's entry-level transmission (called the Tow Master) features a triple-disc torque converter with a billet front cover, new clutch plates, custom pressure plates, a modified coast clutch drum and reverse hub assembly, a modified valvebody, and is rated to support 375 hp at the wheels. It also comes with a written, 3-year/50,000-mile warranty. And the best part is: At only $3,600, it doesn't cost an arm and a leg to have a reliable, built automatic transmission. But don't let the low price mislead you. By machining his own components and doing nearly everything in-house, Wood is able to keep his overhead costs very low.
Shifting Mannerisms
We don't know what it is about the aftermarket, but neck-snapping shifts aren't ideal in built automatics intended for street use, or in towing applications. Once the tires spin and traction is lost (during a hard shift) you've often already lost the race, or some of your towing momentum (there's nothing worse than anticipating a whiplash-like shift with 12,000 pounds behind you). We agree with Wood that the best shift a transmission can make is a nice, clean shift transition with a very quick rpm drop-not one so firm you feel it in the truck's dash.

2015 Ford F-250 Specifications

VIEW ALL
Fair Market Price $29,960
MSRP $31,810
Editors' Overall Rating
Mileage N/A City / N/A Highway
Engine 6.2L V8
Horse Power 385 hp @ 5,500 rpm
Torque 405 ft lb of torque @ 4,500 rpm
See all Specifications

Sources

Transgo
El Monte, CA 91733
626-443-7451
http://www.transgo.com/
BorgWarner
Auburn Hills, MI 48326
248-754-9200
http://www.borgwarner.com
John Wood Automotive
Holtville, CA 92250
760-356-9421
www.jwtt.com
PDQ Automatic Transmission Parts
Sacramento, CA 95828
800-852-3351
http://www.pdqparts.com/

MOST POPULAR

Truck Trend Network

TRUCK RESEARCH SNAPSHOT

Ford F 250

Fair Market Price
$29,960
Editors' Overall Rating
Basic Specifications
MSRP: $31,810
Mileage: N/A
Engine: 6.2L V8
get a free quote

Subscribe Today and Save up to 83%!

Subscribe Truck Trend Magazine

Subscribe to:

Truck Trend
Magazine

PRINT DIGITAL
Subscribe Diesel Power Magazine

Subscribe to:

Diesel Power
Magazine

PRINT DIGITAL
Subscribe Truckin Magazine

Subscribe to:

Truckin
Magazine

PRINT DIGITAL
SUBSCRIBE TO A MAGAZINE
TO TOP