How do you test the LSD?

[j rick kirby]

I keep thinking that my LSD is gone because of the amount of tire spin coming off of corners and I can't tell if it's one or both spinning. But traction has gone away. The other day from a stop and on an uphill incline I let it fly and laid 2 of the prettiest black marks you have ever seen. Is this a good test or is there another and better way?

[DSG2003Mach1]

thats about the only way I know. Maybe try it a couple times relatively close together, if it never peg legs Id have to think its ok

[j rick kirby]

I have also added bigger sway bars so I am wondering if the bigger bar is not letting the inside tire droop enough to get traction.

[slojunk91]

Sway bars or really anything outside the diff can't affect it. Sounds like its working. A carbon disc rebuild is easy and affordable for the most part. LIMITED means its not a spool. There is some "give" cornering. Straight line should be even or close to it.

[311-420]

How do I test LSD? Well....

But seriously, it sounds like it's working to me if it's laying down rubber like you say. A thicker sway bar is only going to increase the spring rate when the car is loaded in a corner, so if you were going straight I can't see that having much effect. As mentioned, the clutch rebuild is cheap end easy if you just want peace of mind. That's one reason I got the 31 spline cobra differential when I built my rear.

[old school]

This had a whole different meaning when we were growing up! We usually found who had the best album collection and black light posters lol

[j rick kirby]

Originally Posted by 311-420

How do I test LSD? Well....

But seriously, it sounds like it's working to me if it's laying down rubber like you say. A thicker sway bar is only going to increase the spring rate when the car is loaded in a corner, so if you were going straight I can't see that having much effect. As mentioned, the clutch rebuild is cheap end easy if you just want peace of mind. That's one reason I got the 31 spline cobra differential when I built my rear.

I'm thinking coming out of corners the inside wheel is not drooping enough to get traction. Like a FWD car having the inside rear wheel off of the ground on corner exit because the rear is so stiff with a big bar.

[311-420]

Originally Posted by j rick kirby

I'm thinking coming out of corners the inside wheel is not drooping enough to get traction. Like a FWD car having the inside rear wheel off of the ground on corner exit because the rear is so stiff with a big bar.

The inside wheel would be mostly unloaded depending how hard you're driving, and therefore unaffected by the sway bar. Atleast that's my understanding

The inside wheel, as I'm sure you know, will always be the first to spin. Camber settings (heating/manipulating the rear end housing) or switching to an IRS are the only ways I'm award of to combat that issue. But I'll tell you right now, there's waaayyy more trade-offs going to an IRS than people think. Ford (SVT) was in over their head when they cobbled together the SN95 IRS rears. Speaking from 5 yrs experience.

[j rick kirby]

Originally Posted by 311-420

The inside wheel would be mostly unloaded depending how hard you're driving, and therefore unaffected by the sway bar. Atleast that's my understanding

The inside wheel, as I'm sure you know, will always be the first to spin. Camber settings (heating/manipulating the rear end housing) or switching to an IRS are the only ways I'm award of to combat that issue. But I'll tell you right now, there's waaayyy more trade-offs going to an IRS than people think. Ford (SVT) was in over their head when they cobbled together the SN95 IRS rears. Speaking from 5 yrs experience.

Mostly unloaded would be the problem and since the outside is compressed I am thinking the sway bar is magnifying the unloading. Think about it.

[Mach828]

I use donuts to test mine

[slojunk91]

Or use this test method^^^^^^

[j rick kirby]

Originally Posted by slojunk91

or use this test method^^^^^^

wtf?

[logan03co]

Originally Posted by j rick kirby

wtf?

I believe he was talking about the post above his....doing donuts.

[slojunk91]

Originally Posted by logan03co

I believe he was talking about the post above his....doing donuts.

Yes....Do donuts.

[j rick kirby]

I believe this all adds up to nobody here really knows.

[slojunk91]

Originally Posted by j rick kirby

I believe this all adds up to nobody here really knows.

Wow you nailed it!!! NO ONE on here knows anything about a traction loc. wtf?

[fastlane]

Jack up the left wheel and turn it using a torque wrench. It should take around 100 ft lbs to turn the wheel if the clutches are still good.

[j rick kirby]

Originally Posted by fastlane

Jack up the left wheel and turn it using a torque wrench. It should take around 100 ft lbs to turn the wheel if the clutches are still good.

I'll try that. Which lug should I use?

[fastlane]

Originally Posted by j rick kirby

I'll try that. Which lug should I use?

It doesn't matter which one.

[j rick kirby]

Originally Posted by fastlane

It doesn't matter which one.

Turn it forward or backwards?

[fastlane]

I usually test by turning the wheel clockwise so I don't end up loosening the lug nut. It will turn in either direction. You are just testing the amount of force it takes to slip the clutch pack. If it take significantly less than 100 ft. lbs. the clutches are shot and you need a rebuild.

[j rick kirby]

Got it and thanks.

[Nekasrof]

I'm really surprised you haven't put in a real diff yet. Trash that thing and get a T2R and you'll never replace it or break it. I've had mine in the car since 2011 and it puts up with an ungodly amount of punishment with the 315s.

This is the one I'm using. I only pulled the link for example.
https://fordracingpartsbydonwood.com...r-m-4204-t31h/

While it's a little pricey, I don't need to have it rebuilt or replaced every year. It now has about 3500 miles on it. Primarily hillclimb miles.

[j rick kirby]

Originally Posted by Nekasrof

I'm really surprised you haven't put in a real diff yet. Trash that thing and get a T2R and you'll never replace it or break it. I've had mine in the car since 2011 and it puts up with an ungodly amount of punishment with the 315s.

This is the one I'm using. I only pulled the link for example.
https://fordracingpartsbydonwood.com...r-m-4204-t31h/

While it's a little pricey, I don't need to have it rebuilt or replaced every year. It now has about 3500 miles on it. Primarily hillclimb miles.

Interesting you mention that as that's what I'm thinking about. Thanks.