Trying to help my father-in-law out with getting his truck where he wants it. It has been past around his family a bit. According to him the rear end was swapped out for a 3/4 ton. I am guessing f250+. I do not know much about trucks or 4 wheel drive for that matter, more of a Mustang/Civic guy. He is wanting to swap the front driveline(?) out for a 3/4 ton 8 bolt as well. Apparently the gear ratio has to match the rear?

So here is what I have so far. The axle code is C5. Which seems to mean it had a Splicer-Dana 60.2/4.10-1/Limited Slip. So assuming whoever swapped the rear did it right it should still be a 4.10-1 in order for the 4 wheel drive to still work.

So anyone want to point me in the right direction for vehicles I could source the correct parts from? Or how to identify the correct parts?

 

1965 F100 w/AXLE code C5: Spicer/Dana 60.2 - 4.10-1 with Limited Slip.

F100 with Ford 9 inch & Spicer/Dana 44, 60.2 & 60.3 rear axles: 5 lug wheels on a 5.50" bolt circle.

F250 Spicer/Dana 60: 8 lug wheels on a 6.50" bolt circle.

 

You need a front end Dana 44 out of a 4wd truck with a 4:10 ratio. If you are sure that's what the ratio of the rear axle is now. You could pull the cover and count the number of teeth on the ring and pinion gear to find the true ratio. Find the front closed knuckle axle out of a 61-72 F250 4wd these should be a pretty much direct bolt in change out if the ratio matches the rear ratio. A lot of 3/4 ton 4wd trucks of this era ran with a very deep 4:56 gear ratio as these trucks were meant to work and haul loads. Low gearing for crawling along off road where hi speed gears were not needed. Good luck finding one with 4:10 gearing if that is what you really do need. I wouldn't assume that someone changed out the rear end to one with correct gearing that's asking for trouble.

 

Thanks for the info. That is what I was needing. Was thinking about just lifting the rear and rotating the tire and counting how may times the drive shaft goes around but pulling the cover would probably be more accurate. Thought about if I found a truck of that era just pulling the front and rear so I would know they would match.

 

4WD: If rear axle ratio is 4.10 - front driving axle ratio will be 4.09 / If rear is 4.56, front will be 4.55.

 

Thanks Bill yes the front gears would be one digit off of the rears.