Got a beater 99 silverado with the 4l60e in it. Now she has the harsh 1st to 2nd shift problem. After much research I know what the issue is and I have a copy of the GM TSB about the p1870 code.
The issue is with the valve body and wear in the bore of the isolator and regulator valves.
My plan is to replace the valve body itself and this is the perfect truck for me to learn on.
Has anyone done this repair or have any pointers and useful info they would like to share?
BTW this will be my first time cracking open a tranny.

 

Take pictures. Not sure why but i have built many engines, just never touched a tranny as i always paid someone to work on those.

 

For some reason when I tear into a machine I never think to take pics. but this will be different. As of right now its not a issue because of the temps and my commute for the next few months are short. It is a issue when the tranny reaches 200+ deg.
The word transmission scares people.

 

i had an older dodge cummins that had to have serious tranny work by a pro shop...torque converter and new valve body. it was never the same after and i always wondered if i could have done a better job myself.

 

I have the same tranny in my old Chevy,but guess I've been lucky with 263,000 miles. I've changed the filter every 100,000 miles and in between pulled the pan drain plug(first one I've owned that had one!!) every 30,000 miles and changed out the fluid.Holds right at 3 1/2 quarts this way by draining the pan instead of the normal 5 quarts when you drop it with the filter change.There is some "shudder" type oil additive I've heard of that you might try before you tackle a tranny with all the passage ways,etc that's involved. I'm just hoping my old semi retired truck will hold up. OPT