I have a '96 Formula and the tires rotate in opposite directions when jacked up on stands. Now would a broken old worn out posi do this just like a non-posi rear does?

Also, will my 60 fts improve EVEN with DRs with a new posi? I had DRs and the best I could get was a 2.1 60ft. The car runs good too. Just curious.

Thanks.

 

Thats just how the posi works. Dont worry about it.

 

Yes when the posi good it takes a certain amout of rotational torque to make the wheels turn in opposite directions. If they turn easily it's shot.

 

You guys are mistaken. A rear with a posi unit that spins the tires opposite directions is a broken posi unit. Maybe not 100% broken so that it will still spin both tires in a straight line, but not 100% functional either. Your posi unit SHOULD spin both wheels in the same direction when the rear is off the ground.

 

So it's a broken posi, not a 1 wheel peel, right? So where is the best place to get a brand new posi?

 

SLPonline used to sell posi units for reasonable prices, I'm sure they still do... I just haven't been on that site in a while.

 

I just checked and I don't see anything there. I would give Summit or Jeggs a call, try to get something like an Eaton Pro-Posi, something along those lines. That's what has been in my car for about 5-6 years. Eaton Pro-Posi + Motive 3.73's + T/A Girdle w/stud kit + GM Posi additive + Mobil 1 Synthetic gear oil... seems to be doing me pretty good.

 

If you were really up on you technical knowledge you'd know that, as I stated above, even a brand new perfectly working posi has a certain torque required to allow the posi to slip and let the wheels rotate in the opposite direction. There is a tool that you bolt on to the axle, then using a torque wrench you measure the amount of torque that it takes to ''break'' the posi loose. If it takes less than the specified torque then the posi is considered worn out.
Don't be so to state that someone is wrong, it might be you.

 

Umm... well that is not true for ANY posi unit that has ever been in my car, or anyone that I know. The only rears that I have ever seen that rotate in opposite directions are broken posi units or open diffs.



And just to be sure I have been searching the internet for any type of discrepancy towards what I know, but guess what, everything says that if the tires spin the opposite direction you have either a worn posi or an open diff. So I still go by that. My rear spun the tires in opposite directions at one point in time, but it was worn to pieces. New posi unit and gears and my rear has never once spun in oposite directions. So to each his own.


If my rear spun opposite directions I'd get a new posi unit that's all I'm saying.

 

it depends on the type of posi, are we talking torsin or clutch style/auburn. also synthetic fluid in an eaton clutch style posi is not reccommended.

 

I'm sure that the op is talking about if both rear wheels are in the air, and you rotate one side, without holding the other, or applying any kind of force to it, and the wheels spin opposite directions, then yes, I would say there is something wrong. I just put a girdle cover on my rear, and when I turned one wheel, they both when the same direction, and I couldn't hold on enough to one wheel to make it slip, and my car has 163K on it and the rear cover had never been off till then. So I would say if he can make the wheels turn opposite directions by hand then it would be worn, much less if they turn diff directions by themselves.

 

Thank you.

 

This is a true fact. The adhesive that they use to glue the frictions on with can unbond with the use of synth. lube. This is straight from Eaton.

 

This was the point of my post, there is a specific amount of force at which you can turn them in opposite directions. I got into this with the 98 SS, I had it jacked up in gear, changing the tires and while torquing the lugnuts the tire turned. So I did it again and the other tire turned in the opposite direction and I thought oh great the posi is shot. I got out the service manual and started reading. I found out the there's a certain amount of torque that when applied to the center of the axle at which the posi should slip. So I fabbed up a replica of the J-tool and checked the break-away torque and it was within spec.
Yeah if you can reach up and freely spin the wheel and the other goes the opposite direction with a clutch type posi it's shot. But it's not a spool and has a break away torque spec.

 

so i dont open a new thread, i have my car up on jack stands and when i turn either wheel its pretty hard to spin them. Is this normal? Reason i ask is when i do drive the car it makes a loud whine the faster i go. Sound really bad too. Fluid is full and I dont want to open it up just yet if it could be something else. Prev owner did get the e-brake cble replaced and i was wondering if it was adjusted incorrectly if that could be the problem.