3.73 Ratio Limited Slip Axle

[PwrStrkTrucker]

So The window sticker calls my rear end a "3.73 Ratio Limited Slip Axle" Im not ignorant...owned many trucks are cars in my lifetime...IS THIS A POSI??? Ive attempted to power brake it and I dont think Ive broke loose both tires! Whats up with that? I only tried it once though...Ive been taking it easy on it since purchasing a couple weeks ago. It seems to me that Ford wouldn't NOT put a posi in with a PSD? Isn't that true? Don't they put a posi behind every 6.0??? Is that a posi? Why didn't it break loose on both sides?

[stump0331]

got the same problem, only break one tire loose

[mschn99]

Yes it is a posi...and No...its not a true locker....its a limited slip with clutch packs. The premise behind a limited slip is that it "limits" slip...but during high traction manuvers when the tires have more gripping force than the clutch packs that "lock" the two wheels together....then the clutches intentionally slip. Now in a low traction situation....the clutches would have held both tires like a locker and provided traction from both rear wheels......

[slammedSI]

I was just thinking the same thing. Going around a corner it will only spin one wheel. From a dead stop it will spin both most of the time, the other part of the time it only spin one.

[EODguyJake]

Wait till it's wet...then you'll leave two stripes. :burnout

[Ditty]

Not always in the wet. I enjoy sliding my 2000 PSD around in the wet and only one wheel will spin, limiting my drifting (or power sliding) fun. I have a 3.73 LSD as well. My LSD might need to be rebuilt though, the truck has almost 200,000 miles. Time to get an e-locker!!

[bigd4x4]

My truck has the limited slip option and it does not work in low traction situations either. I backed out of a friends driveway a little too far and one of the back wheels was in the ditch. Guess what. GOT STUCK. That was crap to have to lock in 4 wheel drive because one tire was a little slippery. My 90 f250 didn't act like that. Of course it had a DANA not a STERLING.

[Heat]

Simply stated posi puts power to the wheel with the most traction (i.e. the outside tire in a corner)... If both tire have roughly equal traction both tires will break loose until one has more traction then the other... I've left two black stripes in mine as easily as I do in my '72 beast Buick which is also "just" posi....

Ken....

[PwrStrkTrucker]

So I went and played around a little bit last night. They both break loose like crazy! Reminds me of my SVT Cobra I used to have; sitting there and truck starts to slide out to one side while both are spinning nicely!

The trick is to apply brake pressure carefully. Its a matter or proper brake pressure and waiting for turbo spool up as well. Im finding that as the truck breaks in more and more, its easier and easier to break em loose. I can smash the go pedal and spin em now! Trucks only got 600 miles right now...cant wait for the power goodies!

[spoolin-up]

I have the same rear in my 2006 f350 and a lot of the time when i try to do a line lock its only one tire that spins in the dry, somtimes it takes a couple times to get the posi to kick in. pullin a trailer threw a muddy field in 4wd all 4 wheels were spinning.