'84 Camaro Positraction oil type ?

Just regular 80/90W gear oil.

Don't forget posi additive... (friction modifier... panther piss... usually wicked smelling additive)

I figured on an '84 his clutch cone was probably worn out long ago. I doubt the modifier is going to make any difference. It's mostly for disk type clutches anyway.

I have had 30 Year Old Posi-Trac (Positive Traction)Units that worked just fine with well over 100,000 miles on them. My GM/EaToN 7&1/2 Locker (which some F-bodys have) has 400,000 on it. It NEVER fails to lock when it is supposed to.

Charles

Any Parts Store should have Friction Modifer for Locking/Limited Slip Deferentials. As of Late I have been using Lucas 80w90 Gear oil in all my GM rear ends. Charles (Ok, Ok I have been Priating Lucas from a Company I do service work for. Free is Free)

Hey JimV, I think you might be on to something. I just spun the rear wheels (while off the ground). They spin in opposite directions ! That's not supposed to happen with a posi rear, right ? Do you think that means the "clutch cone " has to be replaced ?

No, they should turn the same way even with a bad clutch. Sounds like you have an open diff. With the trans in neutral put one tire on the ground and try to turn the other one. It should take at least 30lbs of force to turn it (break-away torque). I rarely see OEM limited slip units with more than 70-80K on them that still work well. Maybe if they are driven mostly in straight lines. :-)

How do you know you have a posi unit? If you're going to change the gear oil, you'll be pulling the differential cover and you'll know when you see it. Just have the additive ready and if it's not a posi unit, just don't add it. I guess even if it's an open differential, putting in the additive won't hurt anything, would it?

-Bruce

Check the RPO sticker in the center console for "G80" That will tell you if it has posi in the first place.

On my '84 T/A the tires turn in opposite directions but it has posi-traction and has always spun both tires. Maybe its a characteristic of the "cone style" posi-traction units?

On my '71 and '73 T/A which use the "clutch style" posi-traction the wheels turn in the same direction.

Some Third Gens have a EaToN Locking Diff. Same Diff S-10's use. It's known as a Gov-Lock. You can have one on a lift and play with the tires till you force it to lock. Unless your force it to Lock you might think it open.

The only TRUE way to see whats in a "pig" is to take the cover off and look. Charles