Has anyone successfully fitted a 1532 lock right in a 99 grand vitara rear axle ?? I put one in but it locks and unlocks eraticaly. Just wondering if there are any tricks to setting it up more than what is said in the lock right book?

What exactly is your lockrite doing?  Is it locking/unlocking when driving in a straight line?   Locking/unlocking when cornering?

 I haven't installed mine yet... but I recall reviewing the install instructions from Powertrax cautioning to be sure the side gears (which you re-use from your diff) are not "heavily used" - translated meaning that your side gears have depressions on the sides of the teeth, the tops are rolled smooth and highly polished. If they are "heavily used" Powertrax states the Lock-rite won't function properly and states the side gears should be replaced.  

I'm concerned about this point as well because the diffs I have are out of a 2000 model year truck.  I have a 2002 with 150K on it and I am guessing there are at least as many miles on the 2000 diffs.  I cleaned up my 4.88 diffs last night and punch-marked the caps and locks but you can't inspect the side gears until they are disassembled.

Another point Powertrax makes is reinstalling the pinion shaft block.  Not perfectly machined and may fit better on one side than the other.  Did you try setting it in and wiggling it around both ways when you placed it in the cluster to see which side appeared to fit best (to prevent binding)?  Finally, excessively worn thrust washers can cause problems as well.

If I'm not mistaken the 1532 is supplied with couplers that replace the sidegears, so worn sidegears should not be an issue here.

It is the one with the couplers. So worn side gears aren't the problem . When I assembled it I put the thrust and spring washers back in. Together they measured the 1.1mm wich is within the 1.25 they resomend in the powertrax book. The locker only locks occasionally when it should be locked all the time and unlock on overrun. I will pull it out and have a look where the cross shafts are hitting the drivers and see if they doing thier jobs. It's like they aren't forcing the drivers against the couplers.

Yeah, come to think of it I have the 1512 LR.

I have had to add about 2mm of thrust washers to either side of the couplers in the locker just to get it tight in the carrier. I am wondering if the 1512 would have been a better option as the side gears would have taken up a bit more slack.

Does this carrier match the US 99 GV's???

From the pic, your diff looks the same as any other Tracker/GV diff.   Don't see anything unique.  As I recall the 1512 came with a set of heavy washers.  It seems to me using their couplers would be "more better" than using existing sidegears simply because the meshing would be a better fit and provide longer service life because you are starting with new components.

That is why I got the 1532.

I had to remove some material from the spacers provided to clear the pinion shafts and to make them rest on the pinion block. On the 1512 they only use flat washers which I wouldn't of had any problems.

I seem to have the locker sorted which is good. in the end I took some metal of the spacers and added 2.4mm of thrust washers to get the spacings right.