LSD not working
 

Hey guys,

2005 Ford Ranger Edge 3.0, auto, rwd. I got my truck stuck in snow several times last week, got impatient (oops) and revved the poor girl too hard even when I was well and truly in a snowbank. Since then, when driving, it doesn't feel like the LSD is helping all the much, and when I last got stuck a guy observing commented it seemed that only one wheel was turning. I'm 95% sure that the LSD was working just fine the week before last week's snow. I don't think I can buy a new clutch pack at this point, but I was wondering if replacing the gear oil and the friction modifier would potentially help things?

Thanks for your thoughts!

Just go to a gravel road and punch it from a standing start
If there are 2 tire marks then LS is working
If just one mark then its not

You can rebuild any differential, including Limited Slip


Here is a "skill" my Grandfather taught me many Moons ago when all differentials were OPEN type, lol
If just one wheel is spinning and you are stuck
While wheel is spinning, as slow as you can get it, hold e-brake release handle out and press down on e-brake pedal
The e-brake will slow down the spinning wheel and transfer some power to the non-spinning wheel, and maybe enough to get you unstuck
Its a skill and an "art" and does work

OPEN differential sends all power to the Easiest to turn axle/wheel, which is why the slipping wheel gets all the power
While the e-brake does apply pressure in both rear wheels, the one that's actually turning gets HARDER to turn, so differential transfers some power to the other axle
So you need to apply just enough pressure on the e-brake pedal to get that to happen, the "art" part, the skill part is just knowing this method, lol

And yes it can be hard to do with manual trans, lol, much easier with automatic

Thanks Ron! I'll go looking for a gravel road. Thank you especially for that trick, I am definitely going to keep that in mind, I've been getting stuck a lot since it snowed, lol!

Brief update and one more question. So, finally found a gravel road clear of snow, and all is well! Two tire tracks, functioning LS. My question is, for the purpose of just good maintenance, would it be wise to change out the gear oil and friction modifier in the differential? I've sometimes heard of the clutches depending on old oil to work, and they're working just fine now, and I want to keep it that way as long as possible! So I'm just wondering if I'm more likely to mess up a 16 year old truck if I poke in there and start replacing fluids that probably were never changed before. (221 000 kms, for what it's worth)

Thanks!

Replacing fluid won't hurt anything for sure

The friction modifier is needed because it allows the clutches to SLIP when going around a corner, so its for the "slip" part of limited slip
If you don't use it, rear will be jerky when cornering because axles are locked so can't slip

Thanks Ron! That's good to know, I think that'll be my next maintenance item then.