I have a 1999 jeep grand cherokee laredo and it shutters from 1-2-3.

Mo Par has a specific trans fluid type that is supposed to eliminate chatter. It is supposed to be compatible with dextron III but sometimes that will not work. There also is an additive that can be used but I actually can't remember what it's called. Also, most units will work well with synthetic flluids (I use either Amsoil or B&M racing fluid Both expensive, but worth the added protection) When replacing fluid, remember the pan only contains a bit less than half of what's in there. I generally do a complete filter and fluid change using standard fluid, then about a week later, drain the pan from the plug, fill it with better fluid (synthetic)...about a month later I repeat that to increase percentage of synthetic to a higher level. This is not cheap, but I have had good success in doing this. After final change I also use lucas trans additive.
Even with the added expense, it still is far cheaper than a rebuild.
If after initial change there is no improvement at all (give it a day or two), I'd not bother with folowing through though because likely there is a real internal problem that needs attention (rebuild). Don't discard second and third fluid from replacement. Save it and use to top off any other vehicles you have and it can also be re-used on subsequent changes to other vehicles that use same type fluid.(just make sure you don't get any dirt in it)