This may be a stupid question but, is there anyway to lock a limited-slip rear end. How exactly does limited-slip work is it electronic, can I enguage it by a toggle switch, or would I have to just install a posi lock locker. I don't want to weld it because I still use the truck as a daily driver. It can be a pain in the *** to have one rear tire spin and my truck almost get stuck before I stop and lock the hubs. Any answers would be helpful. thanks.

 

A limited slip works by sensing torque and traction and then distributing as needed. There is no way to lock them. You are thinking of a locker, where the axle physically locks together, vs. a posi-traction where it is a torque biasing unit. You can however, get a locker that is activated by air compression. ARB makes them. Downside is, they cost about 1k or more to get it all together. I am personally going with a Detroit Truetrac limited slip to be used when snow plowing. I received the unit today, from Randy's Ring & Pinion. The Differential Experts. Auto Parts & Services.. They are very knowledgeable and can definitely help you out. Whatever you do though, do not, I repeat, do not, weld your unit.

 

Thank you, yea someone i know welded his rear end in his jeep and he said it squeels around corners. it didnt seem like a smart thing to do... expec. with tires going for 200+.

 

The factory limited slip is garbage! Mine only spins one tire now days.

You need to replace the stock limited slip with a Detroit Trutrac or a Detroit Locker if you want reliable traction.

 

Did you ask this in the off road forum? Lots of knowledge there. I think some of the e-lockers normally work as a posi but can be locked in to work as a full locker when the need arises.

 

That's called a Lincoln locker, and really should not be used on a DD that see's mostly pavement. The stock LS is garbage, it works based on a clutch pack engaging when one tire breaks loose, but it doesn't ever seem to hold up in the real world. Buy either an Eaton LS unit, or just spring for a Detroit locker, they won't ever fail in a stock setup

 

Hey, I know this is a bit dead, but has anyone had any luck getting the dealer to cover the LSD beginning to slip excessively under warranty?

 

change the fluid and get the friction modifier, this helps quite a bit, I installed a truetrack and I love it ( all kinds of traction)

 

@ ssthomps. Sometimes they will cover it. Depends on the dealer as with most things. I've had them replace the clutches before.

 

The LSD on the SDs is nothng more than a preloaded clutch pack, with little preload I might add. No way I would spend a dime rebuilding the stock unit. Go with an aftermarket unit like the Truetrac.

 

Well the trucks still under warranty, and i'm broke college student. So I'll have to wait to get back to a summer job to buy a truetrac

Since you all are being so helpful today. I have a transfer case problem too:
I will be rolling up to a stop sign and flip the switch in 4x4 I hear it engage, the 4x4 light comes on. I come to stop, proceed away from the stop sign, at this point there is a loud slam, the truck is now in 2wd, there is lots of grinding noises, another loud slam, and it now stays in 4x4 until I switch it back to 2wd. I took it to the dealer, the said the changed a solenoid, didnt help. The snow up here will not work with me and the roads are always clear when I have time to take it in. you guys got any leads that I can give them when I take it in. The guys there just look at me like im crazy and this is impossible.

 

change the fluid and use less or NO friction modifier... when i did my fluid i only used half the recommended friction modifier and it still didnt improve the LS much. next time i don't plan on using any.

 

Excellent advice. I always recommend starting with no modifier. If it chatters, add a little. Add a little at a time until chatter goes away.

With Redline 75W140, I used 0 modifier and my LSD works great, even with 160K miles and bone stock original diff. It was fun pulling all the diesels out of the sand! I would consistently fling sand with 3 tires.

 

and for the record, i remember reading royal purple diff fluid already has the friction modifier in it... so if you are looking to restore some life in your LS by running little/no FM, keep that in mind.

 

Alright guys i need a little help here, i'm completely clueless when it come to this stuff.

When you say yours only spins one tire now days, is the LS suppose to spin both? I thought LS meant if one tire spins the other one stays tracking?

Can someone also further explain the difference between a locker rear end and a posi?

I'm just not a fan of the "one wheel peel" (catch s**t from my buddies all the time because of it), and i don't have the $ right now to invest in an aftermarket one like you guys are speaking of.

Thanks, btw I have a 2007 f250 PSD.