Slipping in straight drive and overdrive 124,000 miles

have you told any of the tranny places of problem when they were replacing or working on vehicle ---has the tcm been tested ---and scan for any trouble codes

Hi Scott, The link below is a youtube video showing how to fix your transmition, I hope this helps......CHEERS''

Auto Transmission Problem
https://www.youtube.com/watch?v=WjNbeInU6-4

Fixing Transmission That Slips And Clunks

nice truck.
change fluid and filter. remember to drain converter.
some of these had the output shaft from the engine to transmission go bad so check that too.
there is a module on the side of the trans that does the shifting so I would get a new one. they go bad at your mileage.

I would change the fluid about 4 times,not flush.

Next replace every solenoid in the pan area

Then the filter

If it has a solenoid pack, you get all that in one piece

Do not drive it one foot, until you resolve that issue,
that comes from someone who previously owned
a trans repair business

Fluid gets changed every 30,000 miles ,not
more than 3 years on ALL Vehicles and Power
Steering at same time

It sounds like you have lost overdrive and it is slipping in third. Being a 1998, likely with a lot of miles the trans has probably burnt the direct clutches. If the ATF has a burnt smell then it's time for an overhaul.

first thing i would try is changing the transmission fluid out and filter, i beleive its almost 8 quarts. use a full quart of lucas transmission additive with the new fluid. if this doesn't help, the transmission will either need replaced or rebuilt

Either the cruise control is going out or the torque converter clutch circuit is going out on the trannys overdrive. Do you have check engine light codes? If so you will need to have a computer hooked up to read them. Darrel coleman also has a problem with his car like this and I have suggested the same thing to him

reverse band is a goner

well the low cost way to go first would be to try and change the trans fluids. If the problems still remains the it may be an internal problem

Your transmission fluid contain water,thats why the colour of the fluid changed to pink.And of such the clutch is slipping causing the engine to reve up before shifting - Check transmission cooler.