I have 96 f250. front differential housing broke. got complete unit from yard. same year f250. this one said heavy duty on it though, and mine is xl. didnt think was issue. new diff in. when in 4wd with hubs locked in, is real squirelly (spelling) on snow, and on dry road the engine seems to be fighting drivetrain. unlock hubs or take out of 4x4 and its fine. thought it was alignment issue, but had that done and problem is still there. im pretty sure the gear ratio is incorrect and the front is fighting the rear. does this sound correct? if ratio is wrong, how do i determine correct one? is it hard to change ratio? would it be easier to change rear end, and if so, would that work? i dont want to ruin transfer case/tranny/rear end. any input would be apreciated. thanks.
btw i think shop that did swap probably scrapped old diff. i figured if they didnt i could swap my old gears over to new housing. not sure how much work that is and if its even worth it.
Sounds exactly like you’ve got two different ratios. Only way to fix it is put a new ring and pinion in one of the axles to match the other ratio. I would definitely keep it out of 4x4 until you fix it or you’re going to blow up your transfer case.
I don’t think the center diff can give the front a different ratio over the rear. The problem would lie in the axles themselves. I’d say either your front or rear axle have different gears in them. Easy way to check.
Jack up the truck, put it in 4wd, put trans in N, spin the tires. Count the rotations of the front and rear wheels verse drive axle.
The ratios have to be the same or else you’ll have problems such as you’re describing.
i havent jacked it up yet but im almost 100% the ratio is off. so i have to decide, do i change the front to match the rear, or the rear to match the front. the junkyard part came from a heavy duty model so would i be correct to assume the gearing will be setup for more low end? since im using it for plowing i would think i should get the rear changed to match the front. or use the vin to find what came stock on it and just change the front to original. i would think changing the rear would cost less labor wise but not sure. decisions decisions.
anyone know of any 4wd specialty shops i could take it to?
The rear will probably be cheaper, especially since you could probably find a set of used gears on ebay cheap. Installation will probably run you and additional ~200.
Jack her up and spin them to find out what ratios you have.
if ya need a shop feel free to pm me
update. I talked yard I got diff from. They still have the truck it came from. Rear end still in it. He said give him 100 and my old rear end and it’s all good. Friend with shop said he’d do it for $100. Gonna determine what gear ratio I’d be changing to first. I’m assuming the heavy duty has lower gearing for more low end. Will find out soon. Thanks for all the advice!