14bff help!

[raptorparts]

have a 78 half ton i swapped a 75 14bff into a few years ago using the stock 78 half ton springs..swap went without a hitch after i had the driveshaft madeup for it...wore the 75 rearend out, located a 79 rearend, installed it and it sits 1 inch further back on the springs than the 75 14bff did!!!...i've swapped a bunch of this stuff around and never seen or heard of any perch differences on the 14bff for the years 73-87...i've rechecked to make sure i'm on the dowel pins like i need to be and i am but the wheels are clearly pushed back to the back of the wheel well....WTF!!!

 

[cybrfire]

If you truly are on the centering pins then I'd be at a loss. Try looking at the leaf springs. Leaf spring eyes, bushings that sort of thing. The center pin hole in the perch wallowed out to far? Just some suggestions.

 

[cybrfire]

Drive shaft still hook up the way it did before? Just as a way of checking that has indeed moved back and not an optic illusion.

 

[BAJA_BLAZER]

Maybe you got one of those rare '79 one inch offset spindle 14BFF that I have only heard tell about. /forums/images/graemlins/histerical.gif /forums/images/graemlins/histerical.gif /forums/images/graemlins/histerical.gif /forums/images/graemlins/histerical.gif

It isn't Rocket Science; check to see where the center pin hole is located compared to your old axle.

 

[diesel4me]

Did you change the springs too??.I saw a truck come in my friends shop that someone put new leaf springs in,but they didnt realize the center bolt isnt exactly in the center of the spring,they put the springs in backwards and the rear wheels were back too far in the wheelwells--the driveshaft fell out when he drove it onto the alignment rack lift!. /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif If thats not the case,I dont know what happenned,something must have moved,or maybe the axle is a one year wonder or something--or bent? /forums/images/graemlins/ignore.gif.

 

[85HeartBurb]

Do the perches look stock? maybe the previous owner put aftermarket on to move it back instead of using zero rates?!?