"91 sable tranny...

Hiyas, not new to wrenching, but this axod e got me thinking. it is not shifting into overdrive, and drive is a little sketchy. hooked up to diagnostics and got codes 647 and 648 in countinous (memory) from computer... tranny problem- incorrect gear ratio obtained for 3rd gear....the other one for 4th gear. not sure how to procede....sensor/ electrical problem, or toasted tranny. It has been rebuilt once, with the aluminum piston upgrade to steel and something else. Anyone...cannot find where this code comes from?

Bump

Hi, RE, Your sable trans codes, I don't have an answer right now BUT, I will get back to you with some info. I have access to ford TSB's thru dealer that I retired from...All I did was trans O/H and diagnostics...See Ya, ASAP...Clay.

cool, haven't been able to pinpoint it yet

Hi, I'm Back, RE your shift concerns.....Ford TSB# 94-10-12 covers it, you need to get a TR service kit , ford part # F2DZ-7A247-A, from the dealer only and follow the instructions with the kit....Good Luck, Clay..

Hi, Back again, I should have been more descriptive, The TR, is the trans range sensor located on top of the trans, looks like a neutral safety switch, also check for corroded connections in the white connector on top of the trans, your issue deales with moisture / water intrusion into the TR and harness....See Ya, Clay..

..so, just so I got this right. This connection problem can cause car shifting/ no shifting problems? Just checking before I dump too much money into it.. thanx for your help.

Hi, The TR sensor controlls/tells the ecm what gear the trans is in, If moisture gets into it and shorts it out intermittently it tells the ecm the WRONG thing therefore the ereatic shifts snd service codes snd all kinds of other things, because it is integrated into OTHER electrical circuits in the wiring harness etc...This info is from a retired ford trans tech.....Good Luck, Clay....