A friend of mine has a stock '99 auto 2wd duellie and pulls a 5th wheel. Somewhere around 100k miles. Doesn't run it hard, 60-65 mph. He said that the transmission doesn't shift quite as hard as he would like it, and slips a little. Anyone have any suggestions on what to do, and where to go to get the work done? He's looking for some ideas on what other people have done. Thanks.

 

First, tell him to not get a stock rebuild. There are much better ways to build these trannies.
My choice is DTT
They have the right approach.
Gorends is good too.

 

My coneverter was slipping as well, I went with a Goerend Triple disk converter and Valve body, cost right around 1700, put it in myself, not a complicated job just time consuming the first time. Couldnt be happier, goerend is 100% the best customer service of any place I have ever done business with

 

I got a DTT single disk and Suncoast VB for around $1400. I did not overhaul the rest of the trans and it works great - solid shifts - no slipping,

I adjusted the bands and took the check valve out of the heat exchanger per Suncoast, and installed the deep pan.

Before that I fried my fluid twice with the old slipping factory converter. Try to get it before the converter destroys itself totally anf sends metal through the system. The burned friction material didn't hurt my system - we did flush the cooler by disconnecting the return line from the cooler until it ran clean into a waste oil pan then re-topped off the transmission.