This Jeep gave us a new first – never before had we converted a vehicle from an automatic transmission to a manual transmission, after someone else converted the same vehicle from manual to automatic. Who knew?
Say what? That’s right, this Jeep started wife with a manual transmission. In 2007 Four Wheeler magazine decided to stick a Hemi crate engine in this Jeep, and named this YK “Project Old School”. And for reasons we can’t understand, the clutch pedal arm was welded to the brake pedal arm. That’s right, they went from three pedals to two. A moment of silence please.
Fast forward to 2019 and the Torqueflite 727 automatic transmission was toast – surprise surprise, right? The Jeep’s owner found us and we set to work righting this pedal injustice.
The NV4500 five speed transmission is the perfect choice for this rig. With an iron case, synchronized forward gears, and a 15,000 pound gross vehicle weight rating this is a popular choice for trucks.
Now Four Wheeler mag does get props for installing an Atlas transfer case behind the auto trans, and we re-used the mighty Atlas behind the NV4500.
Being manual transmission snobs, of course we indexed the bellhousing to the crankshaft to ensure proper alignment.
Once we wrapped up the five speed swap (re-swap?) the custom steel skid plate mounted beneath the auto trans no longer fit, so we fabricated a square tube skeleton with removable steel plates.
What can we swap or fabricate for you? Please contact us to start the conversation.
Vehicle: 1991 Jeep Wrangler YJ
Four Wheeler Magazine Project Old School build articles:
Part 1: https://www.motortrend.com/how-to/0704or-1991-jeep-wrangler-hemi-v8/
Part 2: https://www.motortrend.com/how-to/0707or-1991-jeep-wrangler-yj-buildup/
Part 3: https://www.motortrend.com/how-to/0710or-jeep-wrangler-yj/
Part 4: https://www.motortrend.com/features/0801or-1991-jeep-yj-wrangler-project-old-school/