Hey everybody last week I purchased what is supposed to be a non-turbo 86-88 LSD rear diff. It was an ebay purchase and it stated very clearly it was from an 86-88 RX7 NA non-turbo LSD. The price even after shipping was way to hard to pass up and I knew if I hesitated it would sell out from under me. But also being burned with online purchases before I knew I was taking a risk buying it. Knowing it very well could not be an NA LSD.

Either way I don't know how to tell if it's NA LSD or not and was hoping some pictures would clear up my confusion. But I also know sometimes pictures are not enough, if the pictures don't tell the story please inform me on what to look for to help identify this diff.









Also I'm aware the case in the third picture says, "Needs gear set." but after having the diff and LSD inspected it all looks brand new and rebuilt. So I'm guessing it was rebuilt before I bought it.

 

Stick a half shaft in one side and turn it and see if the other side goes the same direction or not.

 

It looks like an LSD.... I'm not sure if it's S4 or S5. Open LSDs look quite a bit different (you can see the spider gears inside)

it actually says "need gear lash set" which is the spacing between the pinion gear and the ring gear.

you use marking compound on the gear and rotate it to see how they're contacting eachother.

 

^ Yes. Take it to a competent, reputable place that does rear ends. It's pretty important to get right. You can even help them out by supplying torque specs. FSM and specs. are around online.

 

Easy to check and set the diff by yourself. Fsm and search around here how to. That's if you're that inclined. Dial indicator and gear marking fluid and a huge micrometer