Not sure what ive got. 1996 1500 pace car V8
Build sheet says, Corporate 9.25 LD rear axle. 3.55 rear axle ratio. Lock up torque converter. 46 re trans.
Yes,ive read about jacking it up and turning the wheels,but still not sure..
Regards.

 

Build sheet should mention limited slip diff. If it doesn't, you don't have one.

 

Jack the rear up and rotate the tires. If both tire rotate in the same direction then you have LSD. If they rotate in different directions. Then you have an open rear diff.

 

So i dont need any additive,just straight gear oil,when i change diff oil ?
Regards.

 

I have one also and mine says"limited slip differential" so if yours don't say that it doesn't have one. There is a sticker under the hood with that info on it.

 

If checking the underhood sticker doesn't list a limited slip differential, you still might have one if someone added it to the truck. Are you the original owner? My truck didn't come with a limited slip unit, but I added a Dana power lock unit to the rear not too long after I purchased the truck from the prior owner. To check, jack up both rear wheels and turn one forward - if the other wheel on the opposite side turns in the same direction, then you have a working limited slip unit in the differential.

 

Once you have raise the rear of the truck and rotate the tires by hand and both tire rotate in the same direction, Then you have limit slip. Recommend 75/140 gear with modifier. If the tires rotate opposite not the same direction. Then you have a open rear end. But I remove the inspection cover and make sure you don't have any broken clips for the limit slip carrier. If its an open rear diff. Use 75/140 gear oil.

 

Looks like i have open diff, no sticker under bonnet, wheels go opposite way when turned., ( would that be in neutral or park ) Would 75/140 gear oil be synthetic or not.
Regards.

 

Yeah, trans in neutral.

75/140 is generally synthetic, and is recommended if you tow/haul a lot.

 

And most of it already has the LSD additive mixed in so read the bottle, can save yourself a step and some $