stock tranny not shifting

[chowder]

i have looked around a bit and not seen anyone experiencing the same problems as i. to begin, i own a 93 explorer xlt. it is a 4by, with auto hubs. i am not sure which transmission it has(i have been a chevy guy). it does have od. firstly, the od used to slip in and out, regardless of pedal pressure, speed, uphill, downhill, anything. but now the thing wont shift on its own anymore. as i am driving, if i bring it up to about 3 grand and gently ease off for a sec, then gently reapply the gas, it shifts with a little slippage. this will need repeated to get 3rd gear as well. reverse is solid. there is no other slippage(i got pissed, threw my 33's on it and mud-slung for a good hour after this first started). i had the tranny flushed at my last oil change, to no avvail. i was told the vacuum modulator could be the cause, so i adjusted it back and forth. this didnt help either. a friend of mine that works at a reputable shop tested the modulator, also said nothing wrong with it. he thinks my tranny is just a doorstop. the truck has 115k orig miles on it. i have no idea if this could be simple or complicated. please, any help would be awesome. i know someone who could rebuild it cheaply, but properly and thouroughly, but its a money issue when your 21 and working on three children. please help. and thank you for your time, this website is awesome.

dave in distress

 

[chowder]

i forgot to mention that when the tranny was flushed, the tech said that the fluid he got out of it was pretty clean, not brand new, but clean. i dont know if that helps.

 

[Glacier991]

A common culprit in the 3-4 shift problem (4th is OD) where you either have erratic shifting or NO OD at all, is often the 3-4 shift solenoid. While the problem there can be electrical (bad wires, shorts, bad computer input, etc) more commonly it is because the stock solenoid has some really fine screen on it, and that screen would get plugged up with small particles. You can either replace it, or clean the screen - yourself, with the transmission in the car. (You will have to drop the pan and remove the valve body.) I'd consider THAT before I got excited about replacing the entire trannie.

 

[wannabe4x4]

my 91 does the same thing. i put in a bottle of Lucas Tranny shift help, i got it at checkers. cost about 15 bucks. i know its the cheap and simple way but i swear it shifts 1000 times better. ive had it in for about 2 months and its seems to be working, just add a bottle in while your rig is idling.

 

[chowder]

thanx guys i really dont want to put a bunch of money into it, but as you read its a 93 with only 115k on it, so i plan to keep it for a while.

 

[Glacier991]

I've got 100,000 more miles than your 93 on my 92... so care for it and it will give you good service. On the subject of that transmission, if you are the curious sort, read the "My A4LD Rebuild Diary" in the useful threads forum..it will answer a lot of questions for you.