I'm not a transmission guy at all, I've recently had my 4l60e fail on me. I sent it to a local performance shot to be rebuilt and once they opened it it was completely destroyed. I've only owned the truck a few months. The builder put trans go parts in, sonnax drums, new input and out put shafts, everything but the casing was changed. Trans failed 86 miles later. 2 4 band was burned and 3 4 clutches were destroyed. Replaced then trans would shutter in lock up and slip 300ish rpm out of lock up. Pulled and they found my pressure control solenoid was faulty from the start and was producing 80psi at max. Replaced and reinstalled. Now to where we currently are. Extreme shudder in lock up, trans is over heating, slipping out of lock up in 4th by 3 to 500 rpm, slip from 2nd to 3rd when hot. Trans has 214 total miles on it starting at 1st rebuild. I've kept the trans temp below 240, I have a snap on scanner so I've been motoring it religiously. At this point the shop I had do the work isn't going to do anything I'm SOL. I've read that the converter is likely the problem because it's been trough all this, was Replaced during 1st rebuild. I've opened the pan and don't see alot of clutch material but see a good bit on metal on my magnets. I'm just looking for advice before I but the tools and equipment to do this myself. Sorry for the long read.

 

Sounds like a crap builder but also it’s a 4L60. Swap to a 4l80e and never worry again.

 

4L80 and dont look back.

 

If your trans temp is getting to 240, you have issue's.

Is the truck modified?

 

Was the transmission coolers cleaned or replaced and lines flushed before putting fresh transmission in?
I've got a ATSG manual for the 4l60 if you need it.
Whats mods to your truck?

 

it's got a 8" RC lift 375 45 22 tires, light cam and headers. Nothing crazy wanted to turbo it just because but I have a drag car to focus on. I ordered a e book if i have to open it just never messed with it before.
yes cleaned and confirmed to be cooling

 

Don't get me wrong it's crossed my mind, but right now i need the truck to tow the track cars and a 2200$ paper weight doesn't set right with me

 

Lift, tires, cam, headers, tune. It only heats up during lock up everything is butter smooth until it starts getting 210ish then shutters and slips. When closer to 225 slip when shifting from 2nd to 3rd

 

The 2200 paper weight that I have now is preventing that.

 

Lock up is when it should be cooling down, not heating up. Your converter is shot for sure and that probably took out the rest of it. Should have been gone through or replaced after the first failure.