Hi! I have a c4, it's a '78 if it matters, in my maverick. Just the other night it started doing this weird thing--it will shift 1-2 fine but from 2-3 it will sometimes shift into third, then back to second, then back to third, then back to second, then back to third....you get the idea. Eventually after several of those it will stay in third. It seems to do it more when it's cold. It does it extremely fast (several shifts in about 3 seconds). I can keep it from doing it by shifting manually from 2nd to third. I checked the fluid level and it is fine, my next idea is to re-adjust the bands. I'm almost positive that the linkage is correct. Any other ideas? Thanks!
Check the vacuum line going into the vacuum modulator on the trans. It may be off or cracked. If the line is ok, it might be the modulator itself...they're not very expensive or difficult to replace. If that's not it, it may be time to tear it back down. I seem to remember having my Mav do this once in the past, and it was the line to the modulator that had been pulled off. Hope this helps.
maxx could be correct, I seem to remember my car doing this at one time. If that vaccuum line is off, or split and leaking, it might do that
