EDO4 Slips When Cold

[Marcus Merritt]

1994 F150; 6 cyl; automatic; 144k miles.... Left home this morning in 80 degree weather and the E4OD automatic transmission seemed to be slipping in D until the truck warmed up. Cranked fine but revved high with little forward motion when I gave it the gas in Drive. Once up to normal operating temperature the transmission performed just fine. Seems to work fine in 1 and 2 gears. Transmission has been rebuilt about 3000 miles back by competent shop. Is there a temperature sensor that sends signals to the transmission that could be the problem? Once the truck warms up to normal operating temperature, all works fine. The problem feels like what low fluid causes but it is full of fluid. Any ideas? Thanks.

 

[O'Rattlecan]

There might be an outside chance that the fluid you're using wasn't fully compatible. Each type of fluid has its own friction modifiers that are compatible with the equipment. I am not a chemist and don't pretend to understand the basics, but this could be part of the issue.

You should also pull the codes and see if there are any codes being thrown, perhaps a vehicle speed sensor (VSS).

Ryan

 

[Marcus Merritt]

E40D follow up

1994; 144k miles; 6 cyl; automatic... a follow up to my question about 'slipping' transmission... took the truck in to the shop that rebuilt the transmission (old world shop, been in business for years and rebuilt 3 other transmissions for me) and they suspected solenoids so replaced the solenoid pack installed when the tranny was rebuilt. No good result, still had that slipping motion when cold. They said they did not think it was the transmission but probably an electrical or electronic connection and recommended a local shop to check. They pulled codes and said I had a 512 'KAM' code and a 225 'No knock signal'. They didn't know if these were causing the problem or not. Anyone know what these two codes mean and how they can be fixed??

Note: Archie, owner of the tranny shop, said 'no charge' when I asked how much I owed. That's a way to keep customers like me.

 

[O'Rattlecan]

Well the cable that talks to the transmission solenoids attaches to the passenger side of the transmission. If you follow the cable, it goes over the top of the transmission, then combines with some other wire harnesses, then leads to some connections on the firewall of the engine bay, below the brake booster.

You could be losing connection on the wire harnesses physically connecting to the transmission, or possibly some of the harness joints up near the engine.

Ryan

 

[Marcus Merritt]

Yes, I suspect a bad connection because, when I bought the truck, the seller said it had sat up for a 'long' time (don't know how long) and I suspect corrosion at connections may be the culprit. Thanks for the info on the wiring. I will get under there and disconnect and reconnect what connections I can and see what happens.

 

[Fellro]

The hydraulics control slippage, not electronics. Electronics control which hydraulic circuit is applied, so if it was electronic, you would have troubles with it shifting, not slipping.

Since it has been rebuilt, it takes out the possibility of the seals being hard, which is commonly caused by age. Once the trans oil would warm up, the seals would soften, then would work fine.

You need to have them do a line pressure test. This is not electronically driven, it is hydraulic. It is possible the fluid caused it, but maybe the seals of the kit didn't hold up, or one got a small cut.