Best/Cheapest Way for Locking Differential

I have a 2006 tacoma 4X4 with the TRD SR5 package and it is currently getting the rear end rebuilt. The rear axle seal leaked all the fluid out and it didn't have any in it for a while and it messed some stuff up. As of right now the mechanic I took it to is just rebuilding it just like stock. Is there any way I can add some sort of limited slip or posi trac mechanism to it so that I can have both rear wheels spin and lock in when one slips. It does have a differential lock button, but you have to be in 4-low to use it. I want to be able to use it in 2 wheel drive and 4-HI.

 

There is a way to re-wire your stock toy e-locker to allow anytime locking.

Google this: gray wire mod

 

do you think there is any risk of running the stock e locker in 2 or 4 Hi since it will be operating at much higher speeds?

 

Yes, there is a risk. It causes under-steering, among other things. That is why Toyota engineers only allow it in 4-low.
However I don't see any issue with locking the rear (2wd or 4wd) when going less then 10 mph. Over that, there is no reason to lock it.