Beefing Up a Ford Dana 35 TTB Axle

Twin Traction Beef

Brian SumnerPhotographer, Writer

Ford introduced the Twin Traction Beam (TTB) in the early 1980s under F-150 trucks. The design, unique to Ford, combines solid and independent axles, uses stamped-steel beams as the axletubes, and pivots off the frame in two spots, much like a pair of scissors. The differential is a third member design that uses a C-clip to retain the passenger-side axleshaft. The complicated axle and suspension made for camber changes as the suspension cycled, leading to accelerated tire wear on the road. All that suspension travel was popular with high-speed off-road racers though, and the design still enjoys a healthy following in the desert.

The downsized Dana 35 TTB first appeared under the 1990 Ranger with the 4.0L engine option and ran through the 1997 model. It was also used under 1991-1994 Explorers. Yes, this is the same differential that has such a bad reputation in the rear of Jeeps. While the ring gear size and differential are the same (that is to say tiny), the TTB Dana 35 uses a high-pinion design in this application and does not suffer from the bent tubes that plague Jeep owners. Still, many TTB owners choose to scrap the axle altogether in favor of a solid-axle swap, but that requires a big investment in parts and time. What if you have already invested in gears and lockers for the Dana 35 TTB under your Explorer or Ranger? This was the case with our 1991 Explorer, which was built for general trail duty on 36-inch tires. We were looking for ways to increase reliability without having to reinvent the wheel.

Strength can be improved in several areas to the Dana 35 TTB using some fabrication and junkyard Dana 44 TTB parts. Stronger knuckles, spindles, stub axles, U-joints, and larger brakes from a 44 TTB make a great way to add extra beef to the Dana 35 beams. This isn’t a bolt-on conversion though; some machine work is required. It will also result in the front wheel pattern changing from 5-on-4 1/2 to 5-on-5 1/2, so it’s important to budget for a new set of wheels and rear wheel adapters. That did not deter us. After a productive trip to the wrecking yard we came home with the front end components from an early 1990s Bronco. That is when the real fun began, as we created a beefier Dana 35 TTB worth keeping.