4l60e issues

[CD82]

i have a 2003 chevy 1500 z71 and left work to go to lunch.
and it would not shift into 4th at all.
so i got back in the truck after getting my food.
and headed back to work and it would not shift into 2nd or 3rd or 4th.
stopped at a light and had nothing but idle speed then it finialy shifted into 1st.
but would not shift any higher than 1st. could this be the internal selonids?
its got 168k on the trans as far as i know its never had any work done to it.
i have had truck about two years now.

spoke to a shop today and explained the issue and he said could be the selonids.
and if it were them his coast of doing the work is 950 it includes going into the.
convertor and looking everything else over and adding a shift kit.

any suggestions or ideas please? ASAP!! thank you

[blacstar]

reman unit is $100 more and comes with a 3yr/100k warranty. don't waste ur money on a weak rebuild.