auto trans computer compatability

[ronnie mullins]

I have a question my 96 4x4 4.0 liters auto tranny gave up the ghost a couple weeks ago[planetarys busted].So the car lot I purchased it from had a tranny installed for me at no cost to me.Now the tranny was a 4r55e[as you know],they put in a 5r55e and the torque converter wont lock up after it warms up[this was a used tranny they had installed].I took it back to several tranny shops and torque converter clutch code came up,the o/d light will blink until you shut the truck off and restart then the light stays off while you are driving,until you stop and it cools back off then the light will come back on.O.K. had it tore down and they said the valve was worn and they installed a Young[maybe Younger]shift kit that supposedly included a new valve the EX shifts better than ever but the light now comes on after driving about 15 miles or so,with the same conditions as above. Now for my question could the computer in my 96 not be totally compatable with the newer trans?And could this be causing the torque converter valve to mal function.I drive about 36 miles one way to work so thats not a problem but I cant go on any trips in it for fear of over heating due to torque converter slippage cooking the tranny fluid.sorry about the long post but I wanted to give the correct info without leaving anything out.THANKS

 

[Cali' Explorer]

Ronnie-
That definately could be the problem. Your old computer had 4 gears, the new one has 5. Your computer does not have what is necessary to go into gear five, and if it feels like it is going into gear five, its most likely just locking the converter in fourth.

As for the CEL, the best way to see what's causing that is to have it taken in and get the codes pulled. Depending on your state, some auto shops may pull the codes free (California is no longer allowed to to my knowledge).

Now, I don't pretend to be a tranny expert at all, I just know that the difference between the 4r55e and the 5r55e is a whole extra gear, which means that thtere's something extra there that wasn't in your old tranny that it can't control. I would start there and ask the tranny guys, they would know best, but I would say this is your problem.

 

[Opera House]

Well, not not more gears but more solenoids. Think the 4R55E had 4 and the 5R55E has 6. The extra gear was a new second made up from first and overdrive. All the other gear ratios are the same. If someone was really clever, you could probably make a 5R run like a 4R. It would only be a 4 speed unless you changed the computer and wiring harness.

 

[BonesDT]

see if brian at apten chips can burn you a chip to configure your computer to work with the new tranny. you'll get some good performance mods while your at it too.

wiring harness is going to be a ***** though.