E350 tranny issue

[coguzzi]

I'm having some issues with my tranny in my 97 E350 7.3PSD and my mechanic buddies who are trying to help me figure it out are scratching there heads--who ironically are at a shop who do alot of transmission work.

anyway, blinking over drive light and hard shifts when its blinking, which is the check engine light for the transmission, throwing it into limp mode=hard shifts. His code reader give a "1728 transmission slip error, convertor clutch fault" but all values on the reader are normal on his test drives with the exception computer is not sending a signal at all to slip the torque convertor.

there thinking is its driving fine after code cleared, try to test it some more with some drives, next thought is if the code comes back to try a new computer.

any people out there who know more about auto trannies than i do have any thoughts?

[r_w]

Check the wiring harness.

[coguzzi]

so my tranny guy had his scanner hooked up to the van and everything reads normal, VSS and all that good stuff, normal. only problem he could find is, the computer was not telling the torque convertor to lock up (or was it slip) in over drive. besides that he said everything seemed fine and could not get the OD light to flash after he cleared the code.

well--i just got the van back and put 30 miles on it--OD light came on and so did hard shifting, turned it of and restart to make it home.

damnit--any ideas here? he things maybe the CA only programming i had to have done for the glow plug monitor might be to blame, im not sold on that.

[1sweetvan]

Go to the Ford truck enthusiasts forum and look for Mark Kovalsky. He's a retired Ford automatic transmission engineer and very helpful. -If you don't get cocky with him.

[coguzzi]

i have actually been talking to him, he had me check my brake lights, stating the computer will never command lock up if one is burnt out--WTF. anyway, i did have a burnt out 3rd brake light, but im still getting same code. my mechanic has always thought i have had 2 different items going on--might have 1 fixed but need to hook it up to the scanner to see if lock up is happening now

[CodyY]

At Cadillac we had issues with converter lockup slippage in the Northstar devilles of the late 90's. Values would show good, but if you pull the pan there is a solenoid in the valve body to control converter lockup. It's O-ring would get hard over time and allow pressurized fluid to pass the solenoid. typically, we just replaced the solenoid

If the problem persisted, we changed the torque converter.

Hope it helps.