92 tranny problems

Hi , im new. Im here to figure out this transmission in this 88 I have.

no overdrive.
Shifts fine otherwise, but if you rev hard there is an audible and slightly scary "CLANK".
I have changed out the computer, which allowed the beast to run. (wouldnt idle at all before the new computer) Now it runs like a scalded monkey, but no over drive.
I have checked thread after thread and this seems to be a somewhat common problem. One guy said it was the altenator not putting out enough voltage for the transmission controller, another said it was the speed controller.
yes, the MIL is on.
no, I havent had the codes scanned because people only do OBD2 round these parts.

I changed the fluid when I got it (120k), it was dirty and looked as if it had never been changed but it wasnt burnt and there were no shavings!
Thus I suspect some freaky controller problem rather than physical damage to the tranny. Though it could be the torque converter I guess.

I would appreciate any and all idea's that would keep me from removing this transmission and putting in another that is possibly bad as well.
Help.......

Ran the codes, only 12 and 41 so no speed sensor problems. I have yet to check the altenator yet.
The big clank is a worry, could that be the torque convertor?

These transmissions were the weak point on these cars. the engines are among the best ever made but the trannys are a different story.

It could be a variety of things but tranny problems are quite difficult to diagnose.

Checked the codes, 12 and 41 so no help there.
Checked the altenator, putting out 14 volts, no help there.

I got a new cam sensor and oil pressure sender (yes, its leaking like a bansheee), going to put those on and see if overdrive decides to join me though im sure it wont.

Whats up with the overdrive clutch that has its own plug, can that go out pretty easy?

For posterity I feel like chronicling my adventures trying to get my piece of junk to have something other than 1st and 2nd gear.

Replaced the cam sensor- no luck, still have a CEL. Bought the pickup magnet, getting psyced and ready to put it in.

Replaced the Oil pressure sensor- NO MORE OIL LEAK, didnt help the drive/overdrive problem. Go figure.

Replaced the modulator valve- no help.

A local mechanic suggested replacing the speed sensor, he said he saw that cause shifting problems once. My speedometer doesnt dance around or act crazy but he said that didnt matter, could still be the problem.

Im gonna throw a bottle of LUCAS to the thing and see if that helps before I drop 40 bucks on the speed sensor. In fact im thinking of sacrificing a virgin before I spend anymore money of this thing. It is pure evil, not like Dr. Evil evil, like my ex-wife EVIL!

on the off chance that anyone reads this, though searching previous threads in this forum makes me think this has to be the least visted site on the web..................

Driving the beast down the road today I noticed that when I am going over 45 and let off the gas the rpms drop as if it just fell into 3rd gear or over drive.
(It shifts once at about 30 MPH and thats the only shifting this thing wants to do.)
But as soon as I start to give it gas again the rpms kick back up. It acutally feels as if it is going into another gear but when I give it fuel it downshifts.

Im not crazy I swear.

Are there bands in the tranny burnt or is it the torque convertor?

Did You Match The Computer By The Serial Numbers Of The Original Some Of Them R Different

Negative. This was an autozone puter that they pulled my EEprom out and stuck it in the new one.

I have a new speedsensor to try, though I dont think it will work. At this point im grasping at straws.

Plus im trying to figure out what a pain it will be to replace the pickup magnet for the cam sensor, Hayes doesnt have anything to say about it.