97FordBoy

hi guys. got a question about my 4x4 system. my 97 f150, with a 5.4L, is my work truck. has a ford 9 inch in the back, and an ifs setup in the front, not sure what style diff it is. i do a ton of towing for work and recreational towing. recently I have noticed that my 4x4 high and low arent living up too my expectations.
my main problem is when i put it in 4x4 to go up my steep snowcovered driveway, i find halfway up if i slow down a bit when backing my trailer up, that when i give it a little more gas, one or two tires will start to spin. and i end up going nowhere.
so then ill try using 4x4 low, now i pretty positive 4x4 low works cause i can hear it engage. now once im engaged in low i put my trans back into gear and attempt to continue backing up. now when i start easing into the gas to get going. i can hear my engine rev up and not one tire moves until im over 3000rpm and at that point the tires immediately break free and spin, but not all 4 just two. usually the rear tires.
now to add some info. my tires are brand new goodyear wrangler a/t. and i do not just put the peddle to the floor and go. i do ease into it slowly.

so hers my question. what options do i have to lock my tires together so they have to move together?
posi lock diffs?
lsd?
front wheel lockers?
changing gear ratios?

thanks in advance for any help.

charliedyal

First off, you have a 9.75 rear, not a 9". It must be a pretty heavy trailer if your revving to 3k before you move or the tires slip, unless your torque converter isn't locking up correctly. Installing a limited slip or locker in the rear end will help greatly as well as getting a higher ratio set of gears.(you have to change front and back) a LSD up front would help with traction in 4 wheel, but not necessary. Check your door sticker for the axle code. If its a letter and number, it already has a LSD rear. If a number & number, its an open diff. If it does have a factory LSD, you may just need new clutches installed in it.

97FordBoy

Thanks for your help, and sorry about the late reply

charliedyal

LOL. 4 months later?? What did you end up doing with it? And, your welcome.

97FordBoy

I havent done anything about it yet. I believe a huge part of my problem is the new tires i have on arent the greatest A/T tires. So im going to upgrade them.
I also went and looked, my axle code is 19, so based off what you have told me. I have an open diff. Which means im going to look into getting a lsd