fresh rebuild 2 weeks ago. today i was pulling on to highway heard a loud bang, the whole truck shook, i knew instantly that 2nd was gone because it acted like it was in nuetral. it shifted to 3rd and i was able to keep going. it had no overdrive. i thought that the sun gear broke so i wasnt worried about not being able to get back going once i stopped.(figured it would still have 1st and 3rd, i have been down the broken sun gear road before.it now has a beast sun gear,so i was told) turned off highway and it wouldnt get into any forward gear. it wasnt fast enough to skip to 3rd and keep going. after stopping i found that reverse works perfectly fine. but no forward gear works from a stop.

if i put it in gear and give it gas, around 4k the speedo will start to climb but it doesnt move any. i was going to have the transfer case rebuilt begining this week due to my 4wd not working. i believe the chain gave out, oes into 4x4 but doesnt put power through front driveshaft. so while its in the shop the trans will be coming out too. thankfully the guy knows what hes doing and is willing to stand behind his work so i know he will find and fix the problem without ripping me off

i was wondering what the possible problem(s) could be. what can break and cause these symptoms. no 1st, 2nd, 4th. thanks for your help.

 

Just because it's a beast doesn't meant they are indestructible. My FLT 4l65e lvl 5 blew the beast up. It Broke and the thermo weld where the spline ring meets the drum. Anyway that's what it sound like to me u broke.. They are not hard to rebuild if everything else is fine. But rebuild or not u will here a hundred people telling u if u want a dependable Trans than get the 4l80 in there

 

I'm going to go with a broken output shaft or an input planet.

 

Could be several things. Pump, Sun shell, Planetaries, Shafts. It's all speculation until you open it up...