need some advice on trans.

[noshift]

My 85 automatic has suddenly stopped shifting...it will shift sometimes, but when it does the digital tach numbers goes wild, showing rpms all up and down the scale even though the rpm bar seems to show actual rpms....i have fluid...it was a little low so i added, then tried again...this last time it just stayed in 1st..any help would be appreciated.....STAY STRONG AMERICA!

 

[c4c5specialist]

Governor assembly

Hi there,
There are usually 2 things that would cause this, your throttle valve cable is misadjusted, or your governor gear is worn.
I think that your governor assembly is worn, creating this condition.
You see, the governor is located in the tailshaft of the transmission, and it is directly responsible for the shift or NO shift of transmissions.
Per bulletin, 87-71-23, the gear would wear out, causing a no shift condition. They redesigned the gear. The part number would be 8663995, and this is the first thing that I would check.
YOu will have to drop your exhaust, however, once dropped, you should have no problem in removing the side plate, and inspecting the governor gear for wear.
Let us know how you make out, c4c5

 

[Ken]

Ya know, when I was down in the garage earlier today working on mine, I had Gordon's book out and was leafing through it while I was taking a break when I came across him describing similar instances with the tach going haywire, and sometimes even going backwards (I don't know what he meant by that, either the analog read-out or the bar graph?). The book is downstairs and I'm too lazy at this point to fetch it for you.

I'm not even sure if it will affect your automatic transmission with the symptoms you describe. Good luck!

BTW, dontcha know that all Corvettes should be manual transmission equipped? :L