How to tell if R200 is LSD

[socorob]

Hi. I am new to the Z world and want to put a Q45 diff in mine. I picked one up from a 98 Q45 with the 3.70 ratio and both shafts turn the same direction when you turn just one side. That's how I always heard you could tell if a diff is LSD. Now I was thinking about picking up an earlier Q diff with 3.54 ratio and read that all 90-96 had LSD. I saw 3 of those model years at the upullit yards but on all of them when you spin one tire, the other side turns the opposite way. I always thought that meant open diff? Am I wrong about that?

[240zip]

Please do a search on this topic.  It's been covered 100's of time. 

 

http://forums.hybridz.org/topic/64241-short-nose-r230-and-r200-info-and-why/

 

With respect to the Q45 differential into a 240Z.  This is what you need.

 

http://www.modern-motorsports.com/catalog/product_info.php?products_id=74&PHPSESSID=9e25b7fab3e9baf204ae3aa017e3d66f

 

Enables installation of a late model viscous R200 short nose (Q45 or Z32), or Z32 R230, or the Nissan Armada R230 (2.94 ratio etc!) into your 1970-1978 Z car.

[socorob]

I have searched and read that thread 3 times before asking since it didn't answer my question. I found the answer (I think) on a 240sx forum. The guy on there said if the car is in neutral or the driveshaft disconnected the wheels will be easy to turn and will turn the same direction is it"s LSD. That"s how the Eaton is on my live axle car, which is what I expected. He then said if its an automatic and in anything but neutral the wheels will be very hard to turn (which they were) and will turn in opposite directions if it's LSD. I'm so used to manuals I didn't even think to check the shifter since the wheels were turning.I'll go back and unhook the driveshaft to see if that makes s difference. Does that info sound correct?

[NewZed]

The FSM's don't even show an open option.  http://www.nicoclub.com/FSM/Q45/

 

It will be expensive.  You might consider the other LSD's, like the Subaru R180 option:

 

http://forums.hybridz.org/topic/78123-subaru-wrx-sti-r180-side-axles/

 

http://forums.hybridz.org/topic/111779-betamotorsports-subaru-stis30-side-axles-wolf-creek-racing/

Edited April 15, 2013 by NewZed

[socorob]

Thanks The diffs and axles are under $100 at the upullit yards. The expensive part is the T3 stuff to get it on the car. I want to get it as strong as easily possible out the gate so I won't have to worry about breaking things down the road. Plus I think the 5 lug setup will give me more brake and wheel options.

[johnc]

Does that info sound correct?

 

No.  The only way to truly verify whether a rear end housing has a LSD of some kind is to remove the rear cover and look inside.  A welded diff or a diff full of sawdust and tar will show the behaviors described by the guy on the 240SX forum.