I use my 99 4cyl 5 speed to haul dirt bikes, and I find myself getting stuck or having difficulty when taking the truck offroad to get to parking areas. The obvious solution would be to sell it and buy a 4wd version, but the one I have runs great, and I've become kind of fond of it. I think a limited slip diff would handle 99% of the offroad situations I run into, and buddies with 4wd can tow me out for the other 1%. How do I go about finding and LSD rear axle for my truck? Or is there an aftermarket option to install in my existing rear axle? Thanks.

 

You have 2 choices.
1) find a LS axle with the same ratio and do an axle swap
2) buy a Thorsen or Detroit Locker LS chunk and swap out the guts of your rear end

Swapping the rear axle is a coin toss. You never know how worn the clutch packs are in a used rear. This will cost $800-$1000.

Swapping out the chunk in the third member requires taking the rear end apart pulling the original ring gear and put it on the new LS and reinstalling it, shimming to the proper gear lash. The Thorson and Detroit units are much better LS than the OEM clutchpack design. This will cost $500 or so for parts and then you need someone with the experience of setting up the gear lash to install it.

 

One option is an Explorer axle. Most of them came stock with limited slip, and a lot of them are 4.10 gearing which would be perfect behind your 4 cylinder. You'll need to cut off the existing spring and shock mounts, then have new ones welded on. Plan on several hours of labor, $125 for the parts to weld on, and about $100 to rebuild the clutch pack. '95-01 will come with disc brakes, so you'll have a little bit of work to do to adapt the parking brake to your current system.

 

Thanks for the replies. Your expertise is appreciated! Given that my truck is a total beater, and it is very rare that I have actually been stuck, it is probably not worth the expense and effort. I'll probably just get some beefier tires and make sure I always have my "come-along" and tow strap. And I'll carry plenty of momentum when I hit the muddy spots!

 

Keep an eye out on Craigslist, Facebook marketplace, etc. You never know what you'll find there. As far as I know (RonD, et al can clarify the details), any newer Ranger axle that has the VSS output on the axle should work for you. Just look for something with a limited slip diff and it will swap directly into your Ranger.

Alternatively, you could install an in carrier locker like a Lockright, Aussie locker, etc... Those will run about $300 and you can install them into your current axle in a couple of hours.

 

OPEN differentials send power to the axle with least resistance to spin

There is a trick you can use to get some power to the "other axle" when stuck
Much easier to do with hand e-brake or automatic trans but can be done in Ranger manual trans

When only one rear wheel is spinning leave it in gear at lowest RPM possible.
Hold E-brake release handle out and apply e-brake, slowly push it down
It will make the spinning wheel harder to turn and the OPEN differential will start to apply power to other axle, which might get you enough grip on a more solid part of road/trail to get rolling and unstuck.
Obviously give it a little gas as you see fit.

It is an acquired skill, lol, and does work, grandfather taught it to me