Originally Posted by zedrone
I have a 2006 Rainier 5.3 with a 4L60E at 70K miles it has cratered. I am looking at rebuilding it and beefing it up to 4L70E specs. It will not be hotrodded but will do some towing. I'm new to this forum, but heard there
are some knowlegeable transmission people here.
What parts failed on your trans? 4L70 trans specs are not massive difference in basic parts of the 4L60 series trans.
5 pinion planets in 4l65 & 70E trans. Servo upgrade (small change), heat treating of input shaft, one extra 3-4 friction.
Changes and up grades on the 4L60 are simple and common.
Unless you broke a shaft or the planets broke apart, a proper rebuild is all that is needed along with common upgrades folks do