Axle/Drivetrain Swaps for Older/Newer F-250s
Q Will a front axle off of an ’06 Ford F-250 fit my ’99 Ford F-250 Super Duty (not the light-duty)? You see, my truck is a two-wheel drive which uses coil springs and a control arm on each side to keep it all in place. The ’06 F-250 also uses a similar setup, but of course with a solid axle instead off the weird twin beam setup that mine has. Also, will the transfer case off of the ’06 F-250 fit my transmission? If not, can I adapt it, and how hard would that be? I know if anyone can get me some for-sure answers, it would be you guys.
Tony Carr, Jr.
A I pretty much had the answer to your question, but just in case I missed something, I went to my good friend and Ford suspension fabricator Jim Cole for a complete answer, and this is what he had to say:
“While the newer coil-spring Dana 60 axle can be adapted to the 1999 chassis, it is going to be more work than just adding the front axle. Crossmembers need to be changed or modified to clear the differential, and the steering box is normally relocated too. Where you may have a problem is that your 1999 may actually still have the early-style wheel bolt pattern that will not match that of the 2006 model; some early-production SDs, made in spring 1998, had the earlier 8-on-6.5 bolt pattern instead of the latter 8-on-170mm. Of course, you could also change out the rear using the one from the donor truck, and then you would be assured of a mating axle gear ratio.
“On the transmission, if your current truck is a manual and the donor truck is a manual, then the better option is to swap the entire transmission and transfer case combination. If they are automatics, they interact with the engine via the computer as to shift points, and you may also have to change out the computer as well as the wiring harness. In some cases, it is possible to swap tailshafts on some of the transmissions to accept the four-wheel-drive tailshaft and thereby the transfer case. Another, usually cheaper, option is to source a ’60s- to mid-’70s Ford Dana 24 or New Process 205 transfer case that is remote-mounted (commonly called “divorced”). This way, the two-wheel-drive transmission is left untouched, and the transfer case is simply mounted on a separate crossmember, with an additional driveline the transmission and T-case. On pickups with a longer wheelbase, this works very well and can save money on some projects.
“Whether this whole conversion is economical or not comes down to whether or not you are looking for a semi-stock-type truck that has four-wheel drive or a lifted custom-suspension 4x4. Time and time again, I will say it is more economical in both time and money to sell the two-wheel drive and buy a factory-built 4x4, though if a custom suspension-lifted truck is the goal, then many times dollars can be saved by starting with the 4x2 version. My shop, Bloody Knuckle Garage, commonly sources the used two-wheel drive vehicles to start custom truck builds, as these vehicles are normally in better condition overall and the entire front suspension, steering system, axle, etc., are being reworked anyway, so it saves money right from the start.”
Dana 44 Full-Floater: How Strong?
Q My truck is a ’73 GMC with a 6-inch suspension lift, 3-inch body lift, and 38.5-inch tires. It has a TH 400 transmission with an NP205 transfer case (twin-stick setup). The rear axle is a large Corporate 14-bolt full-floater, with 5.13:1 gears front and rear. The front end is a Dana 44-FF. I have seen you remark that the Dana 44 is not strong enough for a rig like mine, but I was wondering if it is different if it is a full-floater?
Edward P. Tomney
A My opinion? You will eventually break an axleshaft or the ring and pinion gears—hopefully, not while you’re in a bad location.
While The Dana 44-FF is a full-floating unit, and the axleshafts only have to drive the wheels, the axles are actually the same size as those found in Blazers or ½-ton trucks. You do get a stronger locking hub and spindle assembly.
Yes, we have seen people running a similar combination quite often; however, that does not make it right. It’s sure not something that I would ever run. It is time to start looking for that Dana 60. FW
->“Whether this whole conversion is economical or not comes down to whether or not you are looking for a semi-stock-type truck that has four-wheel drive or a lifted custom-suspension 4x4.”
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