Wondering about budget options for a LSD come spring and first forays into Auto-X (or perhaps now and have better snow traction). I was thinking at first trying a Phantom Grip, but I wonder about long-term longevity(the diff fluid turning into steel slurry). Then, I thought about a used Mazda viscous-coupling. Can a transmission/driveline shop replace the thermoactive goop inside the diff? And what would be needed to swap to a TII unit?

 

just find a clutch type LSD out of an 84-88 na rx7. rebuild that and pop it in.

 

Had no clue such a creature existed; sounds perfect. So 84-85 FB and 86/87/88 FC? What trim levels for each to look for?

 

86-88 gxl n/a will work. if you go to a tII diff you need to have the drive shaft from mazdatrix or have one made to work with the n/a trans.

 

gxl,gtu and t2 or weld a diff :O not trying to start a debate just an option

 

You're wrong, stop giving mis-information.

All the info for the OP's question can be found in the FAQ.

To correct the info though.
Any NA LSD will be a direct swap for you.
A 4.3 viscous from a GTUs, all the other S5 N/A LSD's were 4.1 viscous, but they were only optional. The GTUs was the only S5 N/A that came standard with an LSD.
Or a clutch type from any S4 N/A GTU(Has to be an S4 GTU), Sport, or GXL.
A turbo diff as stated above, will not be a direct swap. As long as you're not putting down serious power an N/A clutch type, or viscous from the cars listed above will work fine. I'd aim for a clutch type, they engage better than a viscous.

 

Phantom Grip has a pretty good reputation among those that use them. They are knocked and given a bad rap by those who don't use them.

Pretty much like anything else on the interweb, lots of 'experts' with opinions they mistake for facts.

 

sry i though he meant wat trims usually come wit lsd didnt mean to mis inform

 

Guys, have a quick Q.

Discussing swapping a FB LSD into a FC pumpkin with another person. Does the FB unit just bolt in? Output shafts, ect, they just match-up? Is it a complete R&R affair?

 

Were there really optional LSDs on S5 NAs? I thought the only S5s that had LSD were the GTUs and the TII. I don't see anything listing LSD as an option in any of the vintage literature I have in my collection.

I think I have heard rumors of a few oddball '91 NAs that allegedly came from the factory with LSD, but I've never seen any actual proof of this.

 

Guys, might have a lead on a 86-88 GXL clutchie. When I inspect the unit, how can I ascertain limited-slip functionality? Will the output shafts be prevented from rotating in opposite directions, or will turning the driveshaft input while holding one of the outputs still want to move both axle stubs?