1978 Ford Bronco Axles for Swap in Jeep MJ [Archive]

JS-Economos

10-25-2003, 07:01 AM

Front axle is a HP Dana 44, 1/2 ton flavor, 65.5" wms-wms. These use the Ford radius arms and c-bushings. On top of the arm, you'll see the stock Ford coil seat. If you want to retain the Ford arms and coil seats, all you do is unbolt the seats from the arms and flip them so that they offset inboard. This will allow better alignment of your coils because they Ford coil seats are slightly outboard. Your coils will still "bow" outwards some, but not enough to matter. Steering and trackbar is up to you. When I do this swap into my XJ, I'll probably reuse my current RE trackbar but I think it'll have to be modified slightly. Also, if for any reason you wish to go to 8 lug outers, the 3/4 ton Ford HP44 outers and brakes are a direct swap, but you'll gain a few inches on the width of the axle. Also, this axle has the cast iron brackets, so there really isn't a way to remove them - you're stuck with the Ford radius arms unless you find a pre '78 F-150 HP44 which have weld on brackets.

The rear 9" is a big bearing, 31 spline housing with drums and stock SOA. The spring perches are set up perfectly for a direct drop under an XJ, but might work on the MJ depending on what the measurement of your perches are. This axle is roughly 64" wms-wms. TONS of 9" options out there, but I think you'll be set with 31 spline guts, however if you decide you want more beef, its out there in the flavor of 33, 35 and even 40 spline guts, but once you go past 31, it gets RATHER pricey. There's a good thread going in NAXJA about 9"s - lots of guys who are running them have chimed in so I think it would be to your benifit to read through it.

I believe I've heard that the HP44 pinion joint is a 1310, which is the same as the D30 pinion joint, but you can find conversion joints from Randy's or Yukon or wherever. You can reuse your stock front driveshaft depending on how much lift you have. Remember that he HP44 pinion is a few inches longer than the D30's, so if you run too long of a shaft, at compression you could punch a hole in the 'case.

Also, a HP9" is nothing more than a 9" housing with an 8.8 3rd member. These are not factory options and I don't know if a factory 8.8 3rd will simply "bolt" in. I know Currie has all the details on this, but I wouldn't bat an eyebrow over it because XJs and MJs have plenty of wheel base to solve the lower pinion issue. Plus the 9" is far stronger than the 8.8.


Pirate4x4.Com > General Tech > Newbie General 4x4 Discussion > 1978 Ford Bronco Axles for Swap in Jeep MJ PDA : 1978 Ford Bronco Axles for Swap in Jeep MJ 89MJComanche 10-24-2003, 10:17 AM I have found a set of axles from a 1978 Ford Bronco Full Size. Is this front axle a ford 9" high pinion?? What about the rear axle?? What was in a 1978 Bronco Rear?? What gear ratios?? hjeepxj 10-24-2003, 11:09 AM Originally posted by 89MJComanche I have found a set of axles from a 1978 Ford Bronco Full Size. Is this front axle a ford 9" high pinion?? What about the rear axle?? What was in a 1978 Bronco Rear?? What gear ratios?? the front is a 44, not sure if its hp or not the rear is a 9" NothernAZxj 10-24-2003, 09:09 PM the front is a HP 44 and the rear is a 9" as for gear ratio check the tags on the sales to see, many, many options with ford! fordman7795 10-24-2003, 11:26 PM i would have to say that more than likely it will be 3.55. only way to tell is to pull the cover. JS-Economos 10-25-2003, 07:01 AM Front axle is a HP Dana 44, 1/2 ton flavor, 65.5" wms-wms. These use the Ford radius arms and c-bushings. On top of the arm, you'll see the stock Ford coil seat. If you want to retain the Ford arms and coil seats, all you do is unbolt the seats from the arms and flip them so that they offset inboard. This will allow better alignment of your coils because they Ford coil seats are slightly outboard. Your coils will still "bow" outwards some, but not enough to matter. Steering and trackbar is up to you. When I do this swap into my XJ, I'll probably reuse my current RE trackbar but I think it'll have to be modified slightly. Also, if for any reason you wish to go to 8 lug outers, the 3/4 ton Ford HP44 outers and brakes are a direct swap, but you'll gain a few inches on the width of the axle. Also, this axle has the cast iron brackets, so there really isn't a way to remove them - you're stuck with the Ford radius arms unless you find a pre '78 F-150 HP44 which have weld on brackets. The rear 9" is a big bearing, 31 spline housing with drums and stock SOA. The spring perches are set up perfectly for a direct drop under an XJ, but might work on the MJ depending on what the measurement of your perches are. This axle is roughly 64" wms-wms. TONS of 9" options out there, but I think you'll be set with 31 spline guts, however if you decide you want more beef, its out there in the flavor of 33, 35 and even 40 spline guts, but once you go past 31, it gets RATHER pricey. There's a good thread going in NAXJA about 9"s - lots of guys who are running them have chimed in so I think it would be to your benifit to read through it. I believe I've heard that the HP44 pinion joint is a 1310, which is the same as the D30 pinion joint, but you can find conversion joints from Randy's or Yukon or wherever. You can reuse your stock front driveshaft depending on how much lift you have. Remember that he HP44 pinion is a few inches longer than the D30's, so if you run too long of a shaft, at compression you could punch a hole in the 'case. Also, a HP9" is nothing more than a 9" housing with an 8.8 3rd member. These are not factory options and I don't know if a factory 8.8 3rd will simply "bolt" in. I know Currie has all the details on this, but I wouldn't bat an eyebrow over it because XJs and MJs have plenty of wheel base to solve the lower pinion issue. Plus the 9" is far stronger than the 8.8.