Originally Posted by Kawabuggy
You are at the life expectancy of that transmission. About 95% of the 4L60Es that we see have between 120K & 150K miles on them. We average 10+ 4L60E's a week so we see them enough. We do sometimes see some that go more than 200K, but it is not that common.
The other factor working against you is that you have the 4 cyl. engine. GM put a higher stall converter behind that engine to help get the vehicle moving. The higher stall converter generates more heat than a standard stall as what is used behind the V8's. It is very common for the converters in the 4 cyls. to fail as a result of the extra heat. It is imperative that you have the cooler for the trans flushed when you rebuild or repair the transmission to get all of the old metal out. It is highly recommended that you install a larger external cooler for the transmission going forward.
GM also put a higher stall TC behind the 4.3 V6's. In the 95+ S-10 the TC used had a code of DBLF. Which is a higher stall than the V8 TC's. I used the DBLF V6 TC behind my Vortec 350 and get a foot stall of around 2800rpm.
So the I-4 has an even higher stall TC. Interesting.
The reason GM needs a higher stalling TC behind the 2.2 is because it doesnt make the torque that the V6 and V8's do. If you had a V8 TC behind a 2.2 the truck would be a dog as the stall speed would be way to low. The more torque you apply to any TC, the higher the stall speed will be. The opposite is true.