hmmmm
1st one:
snapped the output shaft, going to the bank.
2nd one:
snapped the output shaft while cruising around town. sun shell split, and sun gear destroyed
3rd one:
burned all the clutches up, because of poor rebuild.
4th one:
snapped the output shaft, and rear planeteries
5th one.
dissentigrated.......new case bought.
6th one:
front pump, rear output shaft, and planetaries, and the sprags. sun shell/gear destroyed. rear housing cracked.
7th one:
imput shaft sheared, and sprags gone.
8th one.
dissentigrated.......new case bought.
9th one.
front pump, rear output shaft. rear planetaries.
10th one.
went with a diffrent builder, upgraded to the stage II 4L65E from Century Automotive, and Transmissions, had it for 1year, and no problems.

:side note:
Transmissions 3-9 all broke with-in a 4 month period.
currently I have 78,000 miles on the truck. first one went at 22,000 miles

 

70k... no probs w/ transgo shift kit and mods in sig.

 

I can sum mine up in one word:

BOOM

 

The tranny had about 75K on it or so. I took the torque management out not long before it went out. One day on the way to work it lost 4th gear and then 3rd gear by the time I made it to work. I drove it home on the highway in 2nd gear.

Now the rebuilt one I got with better clutches and what not from a local builder is not shifting into third at WOT. It is starting to slip going into third at moderate throttle now also so it's not long for this world I don't think. The 3.42 gears make it nice though cause I can get going pretty quick in 1st in 2nd. I don't dog it anymore going into third.

This has happened behind a stock internal 5.3L with just bolt ons.

This is gonna be a long thread I have a feeling.

 

1st trans- 22,000 bolt ons onlyGoing to the bank at lunch. hammered on it and on the 1-2 shift lost 2nd, 4th and reverse. burnt clutches, sheered sun gear and shell, broken bands. Rebuilt under warranty.
2nd time same trans case. 35,000 bolt ons and converter.never saw track time with converter. eating a biscuit in traffic going to work. Eased off from red light and just didnt have 3rd or 4th gear. replaced with reman trans under warranty.
Same converter, servos and shift kit in this trans, 6k miles no problems

 

I have blown up 4 in 6 months Mainly 3-4 clutch burn up and one the planetarie and clutches

 

1st- 3000 miles after rebuild, all of the tabs that the snap ring for the 3-4 clutch is held in by sheared off.

2nd- Rear planetary gearset destroyed, sun gear entirely stripped

 

Most of mine went out with a boom.I did have one that lost a pump the revs started rising and the truck kept going slower until it coasted to a stop,about 300 miles from home.