
I tell customers that drive like that "You need a 4L80E Or you need learn that 4L60E's have a "duty cycle" & drive them accordingly. Then repeat this over & over, The Clutch Pack cannot cool down! I'm sure you have seen the guys that get up in high gear, Then Stomp on it.Forcing a 4-2 downshift & let it up shift at WOT into 3rd & 4th. The 3-4's can only handle so many repetitious on/off cycles before they get REALLY hot. On good/low mileage units that burn down 3-4's for no "apparent" reason is generally caused by the Human driving it. Of course a leak in the 3-4 apply circuit will cause it to. APPLICATION: 92 - 95 LT1 ENGINES PARTS INCLUDED: 1994-1995 PCM PROGRAMMING (NO PCM) NOTES: This includes programming for any stock engine application listed above. The 3-4 Clutches burning down is the next common failure, On high mileage units.The hydraulic integrity (Poor line pressure rise)of the unit degrades over time & the 3-4's are the first thing to go.

Sonnax has a "Smart Shell" that 100% fixes this issue.

My theory on the Sun Shell is, At first GM made them to hard, And flexing at the Splines would fatigue the metal, Then they Updated it to softer steel.Then the Splines would strip clean off. I build them for a living & don't have a full explanation, I have seen some go 300K plus, Some go 50K and die.
