I know I have a 9 inch 3.5 gear ratio. But idk whether I have posi or lockers or if it'd bc a gear lock or clutch. When I jack up the rear, I can spin one tire without the other. It seems like if I was able to exert enough force on the tire, the other would spin the opposite way bc I can see it barely move. If I spin one tire, then run to the other side and spin the other the opposite way, it will keep the opposite tire spinning but I'm guessing I just can't exert enough force on it from a dead stop? And also, if I spin the drive shafts by hand, it spins both tires. In the same direction of course. Any ideas what I've got? I know I leave 2 marks on the pavement when I squeal em a little haha so maybe it's lockers?

 

Every one I've seen if you spin one tire and the other spins the opposite...that's an open rear end. If you spin one side TIRE and the other side spins with it then it's a locker.
On the rear end tag it will tell you what it was built with. Unknown what someone has done to it since then. All the way to the left and on the bottom row it will either say 3.50 or 3L50. and 9 in the middle.
3.50=3.50 open rear end.
3L50=3.50 locking rear end.
9= 9" ring gear.

 

There are exceptions to this and I have one such example in my truck right now.

I have a Traction-Lok differential and 3.50 gears in the 9-inch housing under my truck --I know it's a Traction-Lok because I installed the 3rd member.

It was a used, wrecking yard take off part that I just took a chance on that it would work like it was supposed to. Unfortunately, I found out after I installed it that the clutches are worn in the differential.

If I turn one tire one way, the other tire turns in the opposite direction, and it acts just like it has an open (single track) differential. The truck still drives, it just isn't directing power to both rear wheels.

This means at a later date, I get to pull the 3rd member and put new clutches in the Traction-Lok differential.

The moral to the story is, if you don't have a differential tag on the 3rd member or an axle code listed on the door jamb to positively identify what it is, the only sure way to know would be to pull the 3rd member from the rear end housing and put a visual on the differential, to determine exactly what it is.

 

What if you jacked one rear wheel off the ground and powered up? Either she would jump the jack or not. Would that not tell you the answer?
Just thinking, not suggesting.

 

That goes back to what wheel is lifted, whether or not it has a Traction-Lok differential and if so, if the clutches in the differential are good or, if they're worn. --worn Traction-Lok clutches will cause the differential to act just like an open differential.

Normally, power with an open differential is sent to the right axle/wheel. If you lifted the right rear tire and tried to "drive" the truck off the jack, you still may not know if the differential was open or locking.

If it was a locking differential but the clutches were heavily worn, you still wouldn't positively know what's in there.

The only sure way to know is to pull the 3rd member from the rear end housing and actually look at it.

If a person doesn't know what they're looking for, to identify an open differential vs a Traction-Lok, the easiest identifier I know of is to look at the heads of the (10) ring gear bolts.

The heads on an open differential will be fully exposed and will require a 3/4" end wrench or socket to remove/install.

If the ring gear bolt heads are partially shrouded by the differential casting, on the left half of the differential, it's a Traction-Lok (or older Ford Equa-Lok) differential.

Traction-Lok differential on left. Open (single track) differential on the right.

http://image.hotrod.com/f/78184813+w...fferential.jpg

The (10) ring gear bolt heads will require a 5/8" socket to remove/install. --unlike the bolts on an open differential, you cannot get an end wrench on the ring gear bolt heads of an Equa-Lok/Traction-Lok differential.

Equa-Lok was produced from 1957-1968. The much improved Traction-Lok came out in 1969 and was produced through 1986. 1969 is the weakest year model of the Traction-Lok due to (4) large holes on the left half of the differential casting. This was revised in 1970 and a solid casting was produced without the (4) large holes.

This is an older Equa-Lok differential. Notice the sand cast look of the differential and the shrouding of the casting around where the ring gear bolt heads go.

http://www.hotrodders.com/forum/atta...4&d=1386777567


This is a '69 Traction-Lok differential. Notice the (4) large holes in the differential left case half. (It's best to stay away from this particular model of the Traction-Lok).



The revised 1970-1986 Traction-Lok differential. Shrouding around ring gear bolts heads. Notice face of the left side of the differential is machined smooth and there are no large holes.



Equa-Lok differentials only came with 28-spline axle gears and with two pinion (spider) gears.

Traction-Lok differentials came in either 28 or 31-spline axle gears and with 2 pinion or much stronger 4 pinion differentials.

Four pinion gears shown in this Traction-Lok differential.

http://diyford.com/wp-content/uploads/2013/10/547.jpg

You can tell how many pinion gears are inside the differential (without opening it up) by counting the number of roll pins visible on the side of the differential that the ring gear teeth are on.

If the differential has (1) roll pin, it's a 2-pinion differential. If there are (3) roll pins, it's a stronger 4-pinion differential.

Notice towards the center, inside of where I have each piece of tape on the ring gear, there's a roll pin. This Traction-Lok has (3) rolls pins so, that means there are 4-pinion gears inside the differential.



Most Ford open differentials have 2-pinion gears but, there are some open differentials with 4-pinions.

 

Excellent. Thank you, Ultra. I will copy this and file it in my notebook.

 

Glad if the information was informative, sir.