it will not up shift and speedometer not working?

2001 CHEVROLET BLAZER
15,000 MILES • 6 CYL • 4WD • AUTOMATIC
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CARL RODELA
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  • 1 POST
had transmission rebuilt because it would not go in to reverse. now it will not up shift and speedo not working. was told it was a speed sensor. replaced and it still is not working. any suggestions as to what it might be so when i take it back (transmission work under warranty) i do not look like i have no idea what i'm talking about.
Jan 22, 2009 at 8:03 PM
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SQM
  • CAR REPAIR CONTRIBUTOR
  • 6,383 POSTS
Hello,

A transmission can have upshift issue with upshifting when it is low of fluid or the filter is plugged.
This can also be triggered by internal leaks in the valve body. If the pressure solenoid is faulty it can also not allow the transmission to upshift.

It is always a good idea to check the transmission fluid level anytime you have a shifting issue.

https://www.2carpros.com/articles/automatic-transmission-problems

Any time you take a vehicle to a shop just let them know what you are experiencing. That way they will have a clear idea of the issue and can diagnose accordingly.
Any shop that rebuilds transmission should be able to diagnose the issue and do the appropriate repairs.

Please let me know of any questions.
Thank you.
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Sep 21, 2021 at 9:45 AM
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