I got a good deal on one of these kits for the R200 differential for my 240sx project, so I decided to give it a shot. The phantom grip is an incredibly simple device that is installed in the case. It consists of 2 shaped steel plates and 4 springs....that's all.
Now are these parts worth $350? Probably not, but the result is.
Basically, as one wheel starts slipping, the plates under spring tension twist in opposite directions and wedge outward on the spider gears. Some people shy away from this unit because they think this will chew up the case and spider gears. I doubt this will happen, since those parts try to force themselves apart under normal operation anyway. This causes friction between the spider gears and the case, and makes the wheels turn at the same speed, blah blah blah. For more info go to Phantom Grip's site at www.phantomgrip.com
This install was done on my 240sx R200 diff with the #908 kit. Since the R200 case is basically the same between the 240 and z31 diffs, you should have no problems installing one in a z. I compared the parts with a z31 diff and did some rough measuring. They appear exactly the same.
Front is 240sx R200 4.11 ,Rear 85 turbo R200 3.545
The pictures make this job seem harder than it really is. Just keep all your parts in order and you'll be fine. It took me 5 hours to do it leasurely putzing around.
Begin by removing the pumpkin from the car. Differentials are heavy so get some help. Take the back off and you will see 2 bearing retainer caps on each side. Remove the 4 bolts for the caps and smell them. Remove the caps. Now you can remove the case assembly from the diff. It will be hard to get out, you can use the Nissan special tool or a prybar. I used a prybar placed on the case and the pumpkin and tapped on the bar with a hammer to pull it out. Pull it out evenly on both sides so it doesn't bind. Some spacers will fall out when it comes out. Don't mix the ones for the left and right sides up, they control the backlash adjustment.
Once out, mark the ring gear's relationship to the case with a paint pen. Remove the bolts for the ring gear in a criss-cross fashion. Use a soft-faced hammer to tap the gear off evenly from the case.
To get the spider gear shaft pin out there is this roll pin that holds it in.
You have to drive it out away from the ring gear flange. My punch wasn't long enough to do this, so I cut the ends off a nail and used that to help push it out. Then you can slide the bigger pin out.
Now you can attempt to slide the phantom grip unit in that space. It probly won't fit. If this happens, phantom grip recommends sanding the gears down until it fits. Don't attempt to hammer phantom grip in, phantom grip may explode with pieces going everywhere. I used an electric grinder with a 60 grit flap disc to sand the axle gears down. Then I hand sanded them flat with 250 grit paper placed on a table. Clean any debris from the gears before reassembling.
Once you have the unit in, you can put the pin back in. Pry the retainer clips off with a screwdriver. Pull the clip pins off by hand.
Now reinstall the ring gear to the case, aligning the mark you made earlier. Coat the ring gear mounting surface and bolts with locktite. Tighten the bolts in a criss-cross fashion and don't let the gear bind on the case while you tighten. Torque the bolts to 69-78 N*m (non-turbo), and 88-98 N*m (turbo, 240sx).
Reinstall the case assembly in the pumpkin with the bearing races. Put in the spacers for each side. Tap in the shim spacer with a soft-faced hammer while watching for binding. Put the bearing caps back on and torque the bolts evenly to 88-98 N*m. Now you can put the cover back on and install your modded diff into the car!
Once you have the axle shafts in, you will notice that you cannot turn them in opposite directions anymore by hand. The rear will feel a lot more stable in turns. I tested mine by turning around a light pole and gradually increased throttle to try to spin the inside tire. Both tires eventually broke loose at the same time and I did a little drift. This is on a car with stock suspension with 145,000 miles on it. Impressive.
