Re: 4L60E or 80E problem
ACDelco and Rock Auto show as either 4L60e OR the 4L80E being used.
As you're having problems with it, I'd say you have the 4L60E because the 4L80E should NEVER have issues behind a 4.8-unless you've been doing neutral drops.
I'd suggest you do a filter change and replace whatever fluid comes out with fresh. Make sure you clean the pan and magnets real good, at 150K miles, they'll be covered.
Any foaming of the coolant in the radiator? The transmission cooler inside the radiator is prone to leaking and coolant in the transmission fluid is fatal to any automatic transmission. I always suggest eliminating the stock cooler and go external. If you overheat the engine it then heats the transmission-which is also fatal for it.
I had a 1999 GMC Savana 1500 with the 305 engine and the 4L60E transmission. It was rebuilt FIVE TIMES in 100,000 miles. This transmission should never be used in any truck application, regardless of engine.
How may I help you?
1971 Monte Carlo SS454-496ci 600hp
1999 Trans Am-500hp
2003 Iszu Ascender XL Limited V8