Possible limited slip diff issue
Thread Starter
|
1st Gear
Joined: Apr 2025
Posts: 1
Likes: 0
Possible limited slip diff issue
I have noticed after a ride out to a friend of mines house that’s about 30 minutes away that while turning sharp it felt like the rear end was binding. It would do this in drive or reverse. After I got home from work today I needed to make a run to tractor supply which is only about 4- 5 miles down the road. When leaving the house I tried turning sharp in drive and reverse and didn’t notice any issue. I also tried it when I arrived and tractor supply and when I returned home and it was fine. I noticed the issue another time when turning while backing a trailer in after towing my small tractor. I just thought the trailer brakes were sticking or something. I haven’t had the truck long. I bought it about 2 months ago with 90k on it. My question is. Could the limited slip modifier go bad and cause this issue? Also I’m thinking of doing a drain and fill to see if that helps. Pretty much all the gear oil I’ve found has a friction modifier in it. Will the friction modifier in it be enough? Should I add the ford friction modifier in also? Would it hurt anything if I did? What’s yalls thought on what’s going on?
MMNC (SS)(Ret)
Joined: Mar 2004
Posts: 11,598
Likes: 145
From: SE Georgia
A fluid change is pretty quick/easy/cheap way to ensure you know what's going on inside the axle. You never know what a prior owner has done. Maybe changed the fluid and used wrong stuff. Can't hurt to open up inspect and refill with correct stuff.
1. FWIW, the friction modifier works by making the LS clutches slip more. It makes the oil slicker so the clutches don't grab as well. I learned this the hard way on my rig when I put normal gear oil into the diff and the clutches basically locked up into a locker. Had to add an entire bottle of modifier before they started acting properly again. If you knew what oil was in the diff, this is what I'd recommend trying first. But with an unknown lube in there, it's better to start from a known Zero state.
2. Are you sure the LS is actually working? Do you get 1 tire fire or 2 tire fire when you spin the tires on grass/dirt? It could be you have a brake caliper sticking instead of a LS issue. Especially as the calipers on these rigs are extremely prone to sticking issues.
1. FWIW, the friction modifier works by making the LS clutches slip more. It makes the oil slicker so the clutches don't grab as well. I learned this the hard way on my rig when I put normal gear oil into the diff and the clutches basically locked up into a locker. Had to add an entire bottle of modifier before they started acting properly again. If you knew what oil was in the diff, this is what I'd recommend trying first. But with an unknown lube in there, it's better to start from a known Zero state.
2. Are you sure the LS is actually working? Do you get 1 tire fire or 2 tire fire when you spin the tires on grass/dirt? It could be you have a brake caliper sticking instead of a LS issue. Especially as the calipers on these rigs are extremely prone to sticking issues.
Thread
Thread Starter
Forum
Replies
Last Post
Buck Dharma Fan
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
35
Feb 10, 2011 07:56 PM
rocknut
Clutch, Transmission, Differential, Axle & Transfer Case
3
Oct 19, 2004 10:37 AM
