Lurch or bad torque converter?

Hi guys, I've searched and read several posts however I haven't been able to find anything that appears to match my situation and I'm hoping maybe someone can give me some insight before I let the tranny shop take my money.

I've had my Taco for 5 years now and I'm nearing the 150k mark, I drive a lot and I tend to drive it pretty hard. About 2 months ago It started to intermittently jerk into first gear after a hard stop or when breaking and turning. If I don't notice it right away when accelerating and let off the pedal the RPM's will get up to 2k+ before it shifts and it hits into gear pretty violently. It does this primarily after a harder than normal stop or as I mentioned when making a turn and hitting the breaks. There is about a 1-2 second pause as the RPM's drop and then it kicks into gear.

Soon after this started I gave it to my mechanic who wanted to try a tranny drain and fill and new filter to start (it was very past due). Immediately after doing this the problem worsened considerably however about 2-3 weeks later it began to do it less and less to where now it barely happens. Around the same time I started driving it gently as I read about axle wrap so there may be some correlation there.

My mechanic wants to change the tranny as he thinks it is the torque converter. Please advise if agree with him or if there is anything else I can try first.

Other details: I've had to change all my U-joints over the past 12 months as well as my carrier bearing twice. Truck is raised 3'' and I have an extra leaf in the rear.

Thanks!
Mat
Tampa, Fl

 

Normally axle wrap would be while you're still sitting and start to let off the brake. The tension will release from the spring giving you that kick feeling. If your rpm's are moving around and it takes time to get into gear, that sounds like the tranny. Did he do the proper fluid level check when doing the fluid change? I only ask because its slightly more complicated than just checking the fluid, given there's no dip stick.