New Limited Slip with no Traction

PUMPT289 · 03-14-2008

I just installed a new lsd with 3.00 gears.it still just wants to spin the passenger side tire.maybe 1 out of 8 times it will leave 2 black stripes on the road in a straight line.I had put ford friction modifier along with new diff oil.is there a better friction modifier or anything to make the lsd hook up better?or maybe I just have a faulty unit ?? any suggestions

bigbad5.0 · 03-14-2008

are you sure it a posi track rear?

PUMPT289 · 03-14-2008

YES,it is a limited slip diff. I can can jack up one side and the tire will barely turn.

PUMPT289 · 03-14-2008

it won't spin freely like an open diff. there is some resistance.But I can still turn the tire by hand.

EACM06 · 03-14-2008

You shouldn't be able to turn one wheel by hand. Especially with a new LSD.
What brand?
Did it come with install instructions? Is there a break-in procedure. Can you add or subtract shims? Did it have a large "S" shaped spring that keeps pressure on the clutch packs? I would definatly go over all instructions two more times to see if you missed anything. If not, maybe a call to the manufacture is in order.

PUMPT289 · 03-14-2008

here is the link to my ebay purchase eBay Motors: 8 inch Ford Mustang ... Falcon posi traction (item 230219310664 end time Feb-05-08 10:23:11 PST)

ieatdrt · 03-14-2008

Oh boy, I just purchased a complete 3rd member from that guy. I had him put in a True Trac though. The breakaway torque may be a little low and that's why you're getting the slip. You should contact him, as this looks like his own custom unit. Ask if it can be adjusted a bit tighter. Sounds to me like he runs on the light side for cornering comfort.

PUMPT289 · 03-15-2008

that's what I was thinking is that the springs are too soft or it needs another shim.I would consider getting a spool but I drive it every day and they say a spooled rear end won't last on the street.

andrewmp6 · 03-15-2008

The normal break in for a lsd is driving in a figure 8 in a parking lot for about 30 mins or at least thats what i been told.

PUMPT289 · 03-15-2008

There was no instructions whatsoever that came with it.So as far as a break-in,I drove about 1-2 miles and to make sure it was completely coated in the diff. oil and then romped on it.In the next 2 miles or so I went around a corner and stepped on it and it lit up the right rear and didn't even try to kick in the left side. Ever since then even on a straight level road it lites up the right side.

EACM06 · 03-15-2008

In his description of the part, he says there are steel friction plates used in the diff.
I know Ford uses a combination of steels and friction material. Although I'm not sure about diffs from companies like Eaton. I thought a clutch pack with alternating friction material/steel discs would be better than just steels. I'm no engineer though.

There must be a way to tighten up the diff to give a more aggresive limited slip action.
Just my thoughts on the subject. Keep us posted! Any info could be good for future use.

PUMPT289 · 03-18-2008

Well after finally getting ahold of the seller,he said i can send it back and he'll make another that will be tighter.I had mentioned that I wanted a rear end that will lock up both tires when torque is applied.he suggested a detroit locker.I have been reading about the locker and the detroit tru trac. I want to do a little road racing and occasional drag race. will the tru trac lite up both tires when the gas is applied no matter what type of road? say if I wanted to fishtail it around a corner is it going to just spin the inside tire since it has less traction and it's not a locker??Basically I want the performance of a spooled rear end but want to be able to drive it on the street without breaking an axle going around corners or chirping the tires when I don't want to get sideways.

PUMPT289 · 03-18-2008

what I want is a rear end that will lock up both tires when I want it to.what I don't want is to step on it and it has posi ,then all the sudden it gets better traction from one side from the road condition and it transfers to the other side. kind of like going side to side.hope this sounds right and you guys get what I'm talking about.

ieatdrt · 03-19-2008

Well, you'll probably be better off with a Detroit locker. It'll stay locked up alot better than a LSD. Although the ratcheting through corners can be annoying, it's not as smooth as a LSD.

The Greek · 03-20-2008

What is it with these E-Bay vendors? Everyone that get stuff off of E-Bay never seems to get any instructions. It seems to me that there should be more friction plates than what I see.

Auburn now has a diff. that can be turned on and off, you may want to check that out. With the instructions I got with my Auburn they tell you not to use synthetic gear lube. Just the regular "Dino" gear lube with a friction modifier.