auto trans acting up...
 

I have a 97 auto. truck has 280K on it , not sure if the trans is stock or rebuilt, i have only owned it for a year. about 2 months ago i pulled a load about 10K up some good inclines and i think way overheated the trans( stupid me my trans temp doesnt work) and ever since then when it shifts from 3rd to 4th it shifts hard and kinda shakes the truck . any ideas?? if its real bad, what do rebuilt trans go for or to rebuil mine? Thanks Kodi

The clutches are probably slipping. That load might have pushed it over the edge and I would'nt drive it much untill it has been rebuilt. Once the clutch material is gone it can cause more expensive damage to your transmission. I rebuild my own so I can't say what a shop would charge. Good luck

I would change the oil and adjust the bands first, specifically the rear band.

If you need a rebuild, with the mods you have I would get one of the majors trannys, Goerends,DTT,ATS, etc.

Probably 3500-4500 depending on the build.

Your perceived "3-4" shift may be torque converter shudder.

how do you get rid of that? new tq converter?

yup if you intend to tow that heavy with an auto call dave goerend he is a great guy and will tell you honestly what you need

Change the fluid and filter first.
Shudder can be caused by additive breakdown from heat.
Use a bottle of lube guard BLACK bottle.
I'd also say to check the pressure first then raise it if not 65-70 psi. Center port passenger side. Will read in drive but not neutral.