2003 gmc envoy 4x4 slt inline 6. What's causing it to not shift after 3rd gear rpms go up an run at 4000 at 40mph?

SOURCE: 2001 Hyundai XG300 won't shift past 3rd gear

sorry to say trans is fried.
Consider a used trans from the bone yard
or a rebuilt one.
An independent auto shop is likely to give you a fair price!!!!!!!!!!!!!!!!!!!

SOURCE: 92 chevy s10 4x4 4.3L manual transmission no 3rd gear

Hi:

Your transmission has 3 shift rails...
1st - 2nd
3rd -4th
5th- Reverse

If your 3rd gear doesn't work , you have an internal transmission problem, such as a syncronizer, or similar fail... There is not much you can fix, without removeing the transmission.

SOURCE: E40d trans will not shift into 3rd or 4th gear, only rev. 1+2

check or replace your thottle position sensor tps that trans needs to know where the throttle is to shift if it is bad it will do as you say wont shift to third
another telltale is it will act like it goes into lockup when shifting into reverse and stall the engine

SOURCE: Where is the transmission speed sensor located for

it's located on the top of the tail end on the passengers side of the transmission

militantbeast

• 100 Answers
• Posted on Oct 24, 2012

SOURCE: I have a 2004 Envoy slt 4wd auto....The car will shift fine from 1st to 2nd gear but rpms climb and it does't go to 3rd. I tried to maunually shift through gears, but it still doesn't get 3rd?

its most def a purely transmission issue i believe its the solenoids. have it taken to a reputable trans shop near and have them diagnose it with there speciall code reader.