fb-rx7

Is there a way to tell if you have an LSD by looks? The motor has been ripped out of the car and the rear axle is next. The guy I bought it from says it has an LSD but I would just like to know for sure.

trochoid

iTrader: (6)

Disc brakes.

blwfly

iTrader: (4)

say you buy one from a junckyard and its rusted what would be inorder to replace
bearings? obviously oil and brake pads but what bout calipers cvs etc de rust and paint also but is there other internal parts to be replaced stainless steal brake line?

blackb15

So, all GSL-SE's have an LSD then? Someone was asking me about this the other day and I wasn't sure.

blwfly

iTrader: (4)

ithink its anything with gsl in it

trochoid

iTrader: (6)

GSL and the SE's all came eqipped originaly with lsd.

blwfly, I would be happy to respond to your questions, but you need to spend some time checking your spelling. I have trouble guessing what you are trying to say sometimes.

fb-rx7

Well I can tell you right now it has drums on the rear and is not a Se but it was a Limited Edition and the guy I bought it from, actual the sale of the car came from here, says in his post that is has an LSD but when I drove it it did not feel like it would grab when one tire would spin.

Naegleria_Fowleri

No offerings of the FB with drum brakes had a LSD, and if the guy did do a LSD swap into the FB, why not do the rear discs as well? That doesn't make much sense considering that the Disc brakes are tons better than the drum brakes.

MosesX605

Another thing to consider is evidently there were complaints of rear-end noise from customers who purchased the GSL model RX-7 and the dealerships often installed open diffs as a 'solution.' So while most disc-brake equipped RX-7s have a limited slip differential, not all of them do. The only way to be certain is to look inside, even testing for wheelspin isn't conclusive since my old '82 GS would leave two black marks consistently on launch, even with an open differential.

trochoid

iTrader: (6)

My 2nd gen with an open diff will leave 2 stripes at launch sometimes too. The biggest difference I notice is hiting 2nd gear hard. The 2nd gen stays straight, the 1st gen gets very tail happy.

RXGOOCH

The best way to check quickly is to get both rear wheels off the ground and spin one by hand if they both spin in the same direction then LSD, if the spin opposite then open.

As far as I understand differentials that will always work, also by design when going straight both wheels will drive on a open so if you’re using that test a 180 from stop is fairly conclusive

ChasRX

LSDs had a yellow label on them, too; identifying them as limited Slip differentials. I almost scrubbed mine to be illegible.

steve84GS TII

The limited edition 83 was based on the GS platform,so it would have had drum brakes and no LSD from the factory.
Yes,its very easy to swap in an LSD third member,but there would be no visual indication of it because the LSD sticker is on the housing,which is still the non-LSD drum housing.The same can be true in reverse,as Moses pointed out.Just because the sticker and discs are there,doesnt mean theres an LSD pumpkin installed.
If the guy wanted to do LSD and discs he would have had to install a complete GSL rearend since you cant just install the caliper and rotors onto the drum rearend housing.That would explain why he only did an LSD swap and left the drums.
Its entirely possible its got an LSD.It could be weak and old,which is why it wont lock up,especially with the relatively anemic 12A engine.A very powerful engine can lock up even a worn out LSD,its the nature of how they work.Even jacking up the wheels and spinning them wont tell you for sure because the intial breakaway preload could be gone from worn spings/plates.In that case youll have to rebuild the LSD or shim it to get your positive action back.

Bottom line......the only way to know FOR SURE....is to drop the pumpkin and check the carrier.OR.....pull an axle shaft and shine a flashlight down the tube.If you see the shiney spider gear pin and the end of the other axle shaft,then its an open diff.If you see a solid wall,then its an LSD.