Hi everyone, I have a 77 automatic.  I recently noticed when I was driving it down the highway about 55-60 mph, the transmission was not engaged while in the drive position.  It has happened a couple times intermittently.  At a very slow speed around 5 mph it noticed it too.  I'm not real sure what is going on.  When it happened on the highway, I put the car in neutral then back in drive and it engaged fine.  I recently updated the interior and put a new automatic shifter in it.  I am wondering if the transmission cable might need to be adjusted/tightened.  Could this maybe be my problem?  Thanks for all of your help!

Sounds like you already know your own solution. I would guess that an adjustment is necessary. Are you saying -that the transmissions -"slips" out of drive while you are driving ? - Coasting -or under acceleration?

check to make sure the vacuum line to the modulator didn't come off. Sounds like symptoms of that...

Good luck

Paul

For sure check the shifter adjustment first, since you did change it. If you hadn't ever noticed this problem before, then that's prolly the culprit.
Check the trans fluid level to be sure it is full, also.

It slips out when under acceleration.  I make sure I keep the fluid levels up so I don't think it is that.  Also, when I changed the shifter, I did not loosen the transmission cable but I will take a look at that.  Where is the adjustment located, is it at the shifter or transmission?  Thanks again to all, I appreciate it!

The cable adjustment, what little there is, is on the linkage where it connects to the trans. Where the cable connects, there is a nut/stud arrangement, the cable fits over the stud with a clip-pin to hold the cable on. The other end of the stud is threaded and goes thru a slot in the linkage that is attached to the trans. The adjustment is done by loosening the nut, and moving the cable.
It's best to adjust it with the trans in Neutral, but make sure it will still go completely into Park.
What kind of shifter did ya get, anyway?


dam spel-chek...Adams' Apple2009-01-13 21:09:47

I got a used stock automatic shifter.  I will check the adjustment at the transmission, thanks for the help!