Posi rear or Not?

[Bar50]

The term 'posi' is short for 'positive traction' a high traction differential. All GM posi's are of the limited slip variety. They never offered a 'locker' Ford nine inches and Dana's have lockers, like Detroit lockers. Seems like Mopar called thier posi's Sure Grip.
Limited slips have the springs like the pic above with small clutch discs that 'slip' as you turn corners. There are some 'govener-track' rear-ends found in some 3/4 ton(14-bolt rearends) and a few S-series trucks. It allows one wheel to spin a set number of times before both wheels pull. Good for mud or ice, bad for drag racing, they come apart like a cheap watch.
For the record, the F-body posi's bolt together, so you cannot see the springs and clutch stacks.

Another thing to watch out for, some roundy-round/dirt track guys will weld only a spot in the spiders so they will have some give, but not be an 'open' differential. They also weld them solid, hence the term "Lincoln Locker" from a Lincoln welder, making them into a spool.

 

[maliblu]

That is an open differential. I work in th axle industry and have seen many open differentials that the axles will spin in the same direction, if the side gear does not move freely it will just rotate the whole diff case and in turn spin both axles in the same direction. The governor track as stated previously is a "locker" differential. Gm puts them in most of there trucks still to this day. They are made by Eaton and called Eaton Lockers. They carry the G80 option code. A lot of people call them gov lockers or sarcastically grenade lockers. They will not hold up to abuse. They look like this.

http://www.nationaldrivetrain.com/posi_lockers/Eaton/Eaton_Locker/Eaton_locker1.html


Just to give some info.

 

[FrIeDTiReS55]

I really appreciate the feed back from everyone that posted on this thread. Now i just have to figure out what to do with the dam thing :x

 

[jazzbo]

That is an open differential. I work in th axle industry and have seen many open differentials that the axles will spin in the same direction, if the side gear does not move freely it will just rotate the whole diff case and in turn spin both axles in the same direction. The governor track as stated previously is a "locker" differential. Gm puts them in most of there trucks still to this day. They are made by Eaton and called Eaton Lockers. They carry the G80 option code. A lot of people call them gov lockers or sarcastically grenade lockers. They will not hold up to abuse. They look like this.

http://www.nationaldrivetrain.com/posi_lockers/Eaton/Eaton_Locker/Eaton_locker1.html


Just to give some info.

Now I am concerned, I am putting together my rear this weekend and that is what I have. Got it from an 88 blazer. LEarned on here to go to a yard and find a s10/blazer/astro van with a g80 code and that was a posi. I am not a rich man and not a drag racer but I do want this to work. What is the pros and cons about this particular unit verses the peg leg i got now. I mean will it be better than what I have now or what.? I dont have the money to go and buy a new posi, I thought this would do ok for just a street cruiser.

 

[unholy1]

That is an open differential. I work in th axle industry and have seen many open differentials that the axles will spin in the same direction, if the side gear does not move freely it will just rotate the whole diff case and in turn spin both axles in the same direction. The governor track as stated previously is a "locker" differential. Gm puts them in most of there trucks still to this day. They are made by Eaton and called Eaton Lockers. They carry the G80 option code. A lot of people call them gov lockers or sarcastically grenade lockers. They will not hold up to abuse. They look like this.

http://www.nationaldrivetrain.com/posi_lockers/Eaton/Eaton_Locker/Eaton_locker1.html


Just to give some info.

Now I am concerned, I am putting together my rear this weekend and that is what I have. Got it from an 88 blazer. LEarned on here to go to a yard and find a s10/blazer/astro van with a g80 code and that was a posi. I am not a rich man and not a drag racer but I do want this to work. What is the pros and cons about this particular unit verses the peg leg i got now. I mean will it be better than what I have now or what.? I dont have the money to go and buy a new posi, I thought this would do ok for just a street cruiser.

The G80 code is the GM code for Positraction. It should be located on the list affixed to the glovebox. A 7.5 axle will work for street duty, but will fold if you take too many trips down the strip.

 

[maliblu]

It will work for street duty and be better then the open diff. There is a video on youtube showing how it works.

http://www.youtube.com/watch?v=KbMZ9vcYVSg

The diff would not last if you are going to be doing a lot of hole shots with stickey tires.