Quote:
Originally Posted by E350
As an owner of a 1993 Ford Bronco bought new and a cherry 1995 Ford Bronco bought used in Texas to replace the worn out '93, I am somewhat familiar with the TTB front axle -- and of all the tire wear problems associated with trying to align them.
I absolutely, positively don't know much about suspensions compared to BajaSportsmobile, so I am really curious to see how a (what I consider to be a "light duty") TTB front axle would work on a 1 ton-plus E350 van.
I am not bashing, just curious. So, pictures would be greatly appreciated.
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Your Bronco and F150s (1/2 ton PU) use a Dana 44 Twin Traction Beams. I have seen a few odd ball versions of the D44 TTB that are very rare and I have no explanation for them but 99.9% of them are basically the same. The weakness of the stock D44 TTB is the stamped steel radius arms, they can bend under minor impact and they are too short, resulting in excessive caster change. The Traction Beams themselves are strong and the spindles, ball joints, u-joints, axles, lock hubs are essentially the same as any straight axle Dana 44 used in Ford, Chevy, Jeep... applications, mostly 1/2 ton vehicles. There are straight axle Dana 44's used in 3/4 ton applications by the same manufacturers, the difference being that they use larger spindles, bearings, steering knuckle, hub... in 8 lug but the same drive axles and u-joints.
Ford did the same thing in some F250 (3/4 ton) TTB trucks - they use a Twin Traction Beam that uses a D44 differential but with larger spindle, inner bearings, steering knuckle... in 8 lug but the same drive axles, u-joints and lock hubs as the lighter D44. These Twin Traction Beams are different in design than the D44 TTBs and the beams and are not interchangeable as the lengths are different. I consider these to be a hybrid "Heavy Duty D44 TTB" and not what I would build off of.
All of the same manufactures at one time or another used a straight axle Dana 60 (there are way too many configuration of the D60 to get into) which is considered to be the "heavy duty" axle of choice in 3/4 an 1 ton on up trucks. These D60's use bigger components than the D44, most importantly the R&P, drive axles, u-joints, spindles, wheel bearings, ball joints, lock hubs...
The Dana 50 Twin Traction Beam used by Ford in 3/4 and 1 ton trucks uses these same D60 sized components. The drive axles, u-joints, spindles, wheel bearings, ball joints, lock hubs... are the same size as the D60s of the same vintage (I say that because the new D60s use unit bearings and are somewhat different) and are just as strong. The D50 TTBs are different in design than the Bronco and F150 D44 TTBs (different lengths) and are not interchangeable.
All of the Bronco and F150s (1/2 ton PU) Dana 44 Twin Traction Beams are suspended with coil springs and located by radius arms. The F250 and F350 with the "Heavy Duty D44 TTB" or the stronger D50 TTB are suspended with leaf springs and have no radius arms as the leaf springs locate the beams.
For years we have been building, prerunning and racing Bronco and F150s with modified D44 TTBs with 37" tires and 600 HP and they hold up terrifically. The simplest modification is relocating the lower Ball Joint outward to change the camber and welding on 2 or 3 tube radius arms that are much longer to reduce caster change. These simple modifications yield 17 inches of front wheel travel on a Bronco with about a 4 inch lift. More complicated builds include lengthening (widening) both Traction Beams from 2.5 to 5 inches to increase track width and reduce camber change.
On my SMB E350 EB, I installed a Dana 50 TTB system using custom tubular radius arms welded to stock D50 TTBs from a 1 ton F350. It is every bit as strong as a Dana 60 in my opinion and has the ride comfort of independent wheel movement. I get 5 inches of bump travel and 7 inches of droop for a total of 12 inches and at a lower ride height. I'm running BFG LT315/70R17 which is reported to be 34.5" dia.
This is a picture of when we were building it:
This is a picture of a highly modified D50 TTB that is on the Blazer Prerunner I am building. It has equal length beams (passenger side beam cross in front of the driver side beam) and gets 24 inches of wheel travel:
A little 60 Mph action in Baja:
[youtube:3u25fqja]http://www.youtube.com/watch?feature=player_detailpage&list=UU_-_gowpHkoogShV9AwPIuQ&v=-9BYrQj2hMw[/youtube:3u25fqja]