My 94 XJ has just started to pop out of 4 low will i put it in a bind. Usually in a bad flex is when it will pop. Any suggestions?

 

If it stays ok on flat ground/mild trails but seems to pop out more when flexed, I'd recommend adjusting the 4wd linkage a little one way or another to tighten it up going into the transfer case. There's a lot of guides on the internet on how to adjust it, I don't need to go into detail.

The other thing I would recommend is chassis stiffeners. If you can keep it from flexing the chassis and linkage, it should stay in gear.