i'm not sure whether my car has posi and don't wanna tear my rear apart to find out. i've heard that if you look at the skidmarks from a burn out you can tell whether its posi or not is this true? i tried this out and my passenger tire left a really black strip for probably 10 feet before the driver side wheel hooked then both of the tires left skid marks for probably 20 feet, do i have posi?

 

You don't have to tear your rear end apart to find out... You just have to do maintenance that is long overdue by now anyway... Sounds like you don't have a posi btw..

 

The only way to tell for sure whether you have a posi without taking the cover off, is to take the cover off.

You don't have to "tear apart" anything, except maybe some silicone sealer.

Odds are probably better than 1000:1 that your car DID NOT come with a posi. As to what's in it now, see the 1st paragraph. From your description though, it doesn't sound like it's changed since it left the factory.

 

If you don't have this it is not a Limited Slip (Posi for the mis-informed).

 

you weill never know for sure til you pull the diff cover and look

sometimes an open axle will spin both tires but usually not, but it happens sometimes

you cant go just by the marks

and posi technically means that power is sent to the wheel with the most traction

oppposite tha with an open in which power is sent to the wheel with the least traction

a locker sends power to both
such as the pow-r-lok units in the trucks, dana 60 axles mainly, in the 60s and 70s, they are nice, ive had a few the last one from a 67 gmc 2500 truck, 4.56 ratio, got it for 100 bucks in a yard, shoulda kept it, ill have to get another one some day




good luck

 

so i take my differential cover off and look for the thing that DJP87Z28 has posted a pic for? also when i have the differential cover off how can i check which rearend gears i have

 

If you see something like what's in the picture with a mess of springs and whatnot, then it has a posi. If it's just a mess of gears, then it's an open differential.

Check for numbers stamped into the ring and pinion gears indicating how many teeth they have, or count the teeth to figure out the ratio.

 

That thing is a Limited Slip carrier and you can check for the stamped ratio on the OD of the ring gear(example 43:7). Post those numbers and someone will give the ratio. My guess it a 2:73 open rear.

 

Or just divide the big number by the small number. (eg. 41 divided by 11 = 3.73)

 

jack the rear up so both rear tires are off the ground.. put it in neutral, take the parking brake off, and try spin one tire.. if the other tire spins the opposite way, you DO NOT have a posi.. if both spin the same way, you have one.. if the other side doesnt spin, something is wrong with your brakes..

 

Your correct cept that you can either jack one side off the ground and the other stays on the ground, and put it in neutral, or as you said cept you wanna leave it in park or gear, and have the e-brake off. if you leave it in neutral with both off the ground they will both spin foward but not at the same rate which could go unnoticed.

 

the tensions and friction of the ring and pinion is greater than the spider gears in your diff.. the only way to overcome that is to have a posi.. if its an open diff, it WILL just spin the other side.. a posi will turn the driveshaft and the other tire.. it could work your way too..

 

All true granted the LSD isnt toasted...


Just pull the cover off the damn thing and be done with it. Im sure its wayyyyyyyyyyy past due for new oil anyways...

 

Check your RPO codes Limited slip=G80

 

Another (maybe more practical) way would be to park your car in a garage. Then go out and buy some EXTRA VIRGIN virgin olive oil and pour it under the right rear wheel. Then have your best friend step on the gas. If only that wheel spins, you don't have posi. If, on the other hand, your car suddenly flies forward and crashes into your work bench, through a pile of old paint cans and tires, and out the far wall of your garage and into your back yard, then congratulations, you have posi!

PS; don't try this at home.

 

just like the title says/ where to look?

 

That would work, granted its not a cooked posi...




RPO codes should be under console lid.

But that only tells you what was int he thing 20 years ago when it rolled out of the factory. The dealer could have changed the rear before anyone even bought it for all we know!