Long before the Allison 1000, Dodge 68RE, and Ford 5R110 transmissions were available, diesel truck manufacturers used transmissions originally designed for gasoline-engine applications. Remember the Dodge 47RH and 47RE behind the Cummins, the TH700R4 and 4L80E behind 6.5L's, and the Ford E4OD behind the Power Stroke? Just goes to show you how much better the diesel drivetrains are from the factory these days.
Speaking of E4OD transmissions, our '97 Power Stroke was being held back in the performance department by the stock slushbox. That is, until we called up North American Diesel Performance and asked for some help. Most notably known for building bulletproof Ford 5R110's these days, NADP's expertise in building rock-solid transmissions neither begins, nor ends with Fords. The guys at NADP have proven over the years that they can build any brand of transmission with the best of them. Since we're turning our '97 F-350 into a tow rig, we opted for one of its Heavy Hauler units to help us get the job done
When our new transmission arrived, we left the installation process up to another expert in the transmission world, Mike Lovrich of Inglewood Transmission. Known for putting together indestructible Allison 1000's, Lovrich is no stranger to E4OD's. His shop was under contract to maintain a fleet of Ford trucks used to construct the 105 freeway in Los Angeles in the early '90s, which led to Lovrich rebuilding and installing several hundred of them. Knowing this, we never thought twice about which shop to go to for the swap. Here's how our Heavy Hauler E4OD install went, along with some post-install driving impressions. DP
 Mike Lovrich, of Inglewood...  Mike Lovrich, of Inglewood Transmission, showed us this OEM torque converter out of a Ford. Notice the black discoloration on the front cover (arrow). This is the result of burning up the converter clutch. |  Once up on Inglewood Transmission's...  Once up on Inglewood Transmission's lift, the first thing removed was the transfer case. First, the technicians disconnected the front and rear driveshafts from the transfer case. |  Next, Inglewood Transmission's...  Next, Inglewood Transmission's technicians removed the transmission crossmember, and all other bracketry before the transfer case could be pulled. |
 Once the transfer case was...  Once the transfer case was unbolted and lowered, as much fluid as possible was drained. Depending on the shop, some leave the transfer case bolted to the transmission and swap it out once the entire assembly is removed. Inglewood's technicians opted to remove it first. |  When the transfer case was...  When the transfer case was out of the way, the pesky OEM transmission pan (with no drain plug) was removed in order to drain all its fluid. Then all of the bellhousing bolts, flexplate bolts, and wiring were removed. |  From this view you can see...  From this view you can see how rusty the factory torque converter had become over the years. The OEM unit (single-disc converter clutch) is definitely the weakest link in E4OD transmissions. |