Limited Slip FAIL

update:

after reading all the info people posted (along with a bunch of worthless bs) i did a little more experimenting.

for all you safety nuts out there: i did this at recess on a crowded kindergarten playground for handicapped children. have a field day with that one.

anyways, i actually did jack up one side and try all of this again at idle speed, already determined that gassing it has no effect other than to obtain a hailstorm of criticism from quite a few folks

anyways, same result was seen. i then lifted both wheels off the ground and they do rotate in the same direction when in neutral.

i decided to do a burnout (and YES, of course i stayed on the playground!)

after a few good attempts at power breaking (pretty hard to break brand new duratracs loose) i got them to spin a litttle...BOTH of them. i had my side views cocked down and saw both tire's spinning...also left two black marks.

after this i went back to the jack and put one side about an inch off the ground. i gradually clicked the parking break down and gave it some gas until....MAGIC, the LSD engaged and the truck drove off the gas. my e brake doesn't feel loose, but maybe it is b/c it took 7 to 8 clicks to accomplish this. i guess i shouldn't have given up when originally experimenting at 3 clicks but i was really looking for a good excuse to buy a rear locker

so to all of you who said that that little bit of resistance on the slipping wheel is necessary, congrats!

chris4x4: i have no idea how you accomplished going up a hill with the LSD and one rear wheel up in the air in 2WD, but i'm definately not doubting you..just wish i could have simulated it.

anyways, case closed. i have a lsd. it works (properly i guess???)

fine print:

only 13 handicapped 5 year olds were harmed or maimed during this experiment. please don't try this at home....go somewhere crowded

 

as a little follow up for all you safety nuts:

on a serious note all of this experimenting, including the first round this weekend, was done in a wide open environment with no one around, no running through houses or over kids as so many of you were picturing. sorry for the disappointment

 

nice work

 

also engaging the ebrake acts like a poor mans locker and will transfer power because the brake is putting pressure on both sides. basically the ebrake is putting pressure on the wheel in the air transfering power to the wheel on the ground. Thats what the lsd is supposed to do...in a clutch style lsd, if one wheel is in the air the clutches will engage and transfer power. The only lsd that required some torque on both sides are non clutch style. (gear driven)

 

generally, but not all the time. my wheeling buddy's f-150 (open diff) will only do single tire burnouts, not mater what surface (dirt, gravel, pavement), or starting position (straing from stop, straght rolling, or rolling turning).

 

Clutch like LSD's are designed for continuous slip but they dont reach full LSD like property until there is some speed difference between steel plates and friction plates (aka axle vs carrier speed) So turning wheel by hand should yield no effect (one wheel spinning other stopped) unless all the friction additive is gone and one is riding friction plates.

 

my point was because op used ebrake there is still no deff answer the lsd is ok...

 

I finally found an 07 DC LB Sport 4x4 with 59,000 miles and purchased it. I was messing around in the sand the other day trying to get my limited slip indicator light to turn on and never could. So, I jacked up one wheel yesterday. With idle speeds and a little bit of gas could not get the tire on the ground to move. I am confused by all of the previous posts, should the truck pull off the jack or not with 1 wheel in the air?

Any help or ideas would be appreciated. At this point I am about to take it in to have the LSD serviced before the 60,000 mile warranty is expired. Should I take it in for service?

 

What indicator ?
If you still have warranty you should take truck to dealer.

EDIT: Reading from this site a lot people will end up burning their LSD's due to negligence. I would say if you are buying used truck, do not expect LSD to be in working condition.

 

Ok, I just looked through the manual again, looks like the LSD indicator lights are only used for the Traction Control System, which I don't have.

So what is the definitive test to see if it is working or not? In other words, how could the Toyota dealership prove to me that it is working without doing a burnout? The service dept. wants to charge me $100 or so if I bring it in and it isn't a problem, so I am trying to figure out if there really is a problem.

thanks

 

You just did the test. If your wheel is not pulling you over the jack then its not working. Not sure what Tech will do to check but hopefully they remove Diff and look at clutch packs but doubt that would cost only $100.
Replace diff fluid/w. additive see what happens.

 

Once it has exceeded it's "breakaway" torque, this setting is usually quite low on OEM LSD clutch packs.

That relates to uneven weight distribution on the 2 wheels. All else being equal, it will spin both, if the co-efficient of friction is the same.

A clutch type LSD will only transmit a pre-determined amount of torque, if there is zero traction at one wheel. This amount has nothing to do with how fast either wheel is turning. It is called the "breakaway" torque setting. Pre-loading the clutch pack by using the E-Brake loads up the clutch pack, allowing it to tranfer more torque. Zexel Torsion diffs are a different type, with different operating pricipals not relevent to our trucks.

Not true, unless you are referring to a Zexel Torsion, or Quafe unit, which has nothing to do with our trucks. Wheel speed difference is not a factor in Tacomas with the mechanical LSD trucks, LSD action is determined by the rate of the pre-load springs, and the torque load.

 

A little Tech for yall...Operational pricipals of the OEM TRD LSD:

This clutch type limited slip is the strongest and most aggressive limited slip differential available from Dana Spicer. It is a clutch type unit using floating cross shafts that ride up on ramps in the case. When power is applied, the shafts ride up the ramps and load the clutches for a positive engagement. A Power-Lok will not lock up 100%, but it is a very durable unit that will hold up fairly well with tall tires. It can be rebuilt, and can be set up smooth or aggressive by changing the clutch design or stacking configuration. However, the case bolts can stretch or loosen after severe use over time.

 

I just got back from the dealership, the tech I talked to says there needs to be traction on both tires for the LSD to work. Kind of bummed to hear it, but atleast it doesn't sound like it is broken.

 

Has anyone tried an 09+ ALSD (electronic) system in the same way?

 

I thought this was a joke, apparently not...WOW.

 

Yes. There is no fooling the electronics, it will allow some difference in wheel speeds, but it will not totally "let go" the way a slipping mechanical unit will.

 

yea but they probably dont start at the same time

 

lol