tranny not shifting to 4th

[cruisingz]

i have a 82 300cd, yesterday my tranny started acting up, shifting from 3rd to 4th doesn't occur most of the time, i have to shift to neutral and back to drive really fast and it'll shift kinda hard. 1-2-3shift very smoothly. also i noticed while i'm cruising on 4th gear it'll shift to 3rd if i let up a little bit on the gas pedal. i have checked fluid level(fluid looks very good too) also checked the bowden cable adjustment. would appreciate any insight on this problem....thanx.....john

[mbonly]

first instint says to check for vacuum problems but it doesn't really sound like vacuum especially when it downshifts after letting up the gas, as you know these trannies you have to smash the pedal to get them to downshift, I will try some Trans X first while some of the more expirienced guys shime in on your post and maybe someone has had the same problem. If theres gunk built up over time that is not letting the fluid into the right chamber in the valve body then the Trans X might dissolve it and solve the problem, is worth a try.

[pawoSD]

Disconnect the kickdown switch under the pedal, black round switch with a cord plugging into it, if its malfunctioning it will prevent a shift to 4th.....unplug it then go driving and see if it solves the prob....it seems to be a common problem. If that doesn't help it could be a more serious problem in the tranny....

[t walgamuth]

is the problem, it seems as if if you drive fast enough, it will go ahead and shift up, too.

tom w