Livinloud

So I just got my first rx7 less than 2 months ago! A buddy and I went for a cruise a few weeks back and he mounted his go pro on his dash. I finally watched the video and realized my 1988 vert has an LSD. As far as I knew they did not come with this. Is there any way I can hoist up the car and look for a marking of what diff I have?

misterstyx69

iTrader: (142)

A sure sign is the tag on the Fill plug at the rear of the diff that says "LSD Fluid Only".

Weimaraner

hmmmmm

Livinloud

Thats easy enough I wont need a hoist. I took a quick look just now, the diff is nice and silver/grey unlike all the other parts-black and silver. The plug is brown, mostly rusted with no marking.

misterstyx69

iTrader: (142)

then you can jack it up and turn say the driver rear wheel,and if the passenger rear wheel goes the same way then it is an LSD.If your buddy is holding it,it will have no choice but going forward when you spin the wheel forward.

An open diff however will "lose grip on the other side" and not spin.

zassou

Was an LSD an optional item or part of a specific equipment package for that year? I also just picked up an 88 vert, loaded with what seems to be all the options available...according to a sticky I found around here somewhere where all the model year/specifications are listed...but I didn't see any reference to LSD.

I saw your video and it was pretty cool how you chirped both the tires on the launch. I just got mine on Friday and have been very gentle with her...she's been a very pampered car before I got her.

Let me know if you're up Collingwood way and we can get together for a black and white 88 vert photo shoot on the shore of Georgian Bay!

Livinloud

I'll do the test this weekend when I have afire d to help hold the other wheel.
Zassou- I'm never ever out that way, BUT I guess ill have to start! You'll be my first 7 buddy lmao!

jibduh

That's only true if it's out of gear, right? If it's in gear, and there's noone on the other wheel, nothing is going to turn until you overcome the compression in the engine?

conversely, an open diff will spin the opposite direction no matter what state the trans is in due to inertia of the gears in the trans vs diff? Is this still true for a clutch based diff?

(just something that I've been wondering about and mulling for a while)

Sgtblue

iTrader: (16)

^Yes. But I took it as a given that the car would be out of gear.
I'm not experienced with the FC, but given their age, the number of previous owners and what I suspect is the ease of swapping certain components like the differential from both the S4 and S5....it's possible that your's isn't 'original' to the car. Still, if it is an LSD and isn't making noise, you scored.

misterstyx69

iTrader: (142)

Why you would have the car, IN Gear, up in the air to test the Rear diff is beyond me..you may as well toss the car on the ground and do a burn out to see if BOTH wheels leave marks(LSD) if not it is a N/A(one wheel Peel).

Livinloud

In gear or not, has nothing to do with LSD as LSD is not a transmission part( for argument sake) I'd leave the car OFF, jack up the back..... And have a friend hold the wheel.
Or
Do a burn out and look t the 2 patched of rubber I just left.

Livinloud

So I just got back from my mechanics. We looked and looked for any markings on my diff and didnt see one. When I spin one wheel, the other does NOT spin. When I 'rip' the wheel- the other one spins.. Is this a clutch type LSD?

toshii

sounds like its not lsd

jibduh

maybe not relevalent here, but those symtoms could be an open, viscous, clutch, or (less likely) electronic differential. for the FC, it's supposed to be open or torsen, so unless you've got an aftermarket unit, I'm going to say it's open.