94 F-150 inline 6 cyl. Complete full tune-up was done first, and then did a complete tranny service all the way down to replacing the over drive soelnoid. Drove like a new truck for a few days and then today on the interstate (after 30 minutes) it started feeling like it was slipping again. Before I did the tranny service the over drive light was blinking, but after replacing the soelnoid it stopped and everything seemed fine. Does anyone have any other ideas? Please help, I don't want to have to ditch the old Ford, but it is looking like I may have to.... This isn't our sole transportation and only gets driven a few miles a day normally.

 

Stupid question, but have you checked to make sure that the tranny is still mounted flush and all the bolts are tight?

 

Yes, It was doing this before I did the complete tune-up and the tranny service. After the tranny service, it ran fine for a few days, just enough for you to think it was fixed, but then after driving it on the interstate (30 mins) it started doing it again.

 

Was the fluid in good shape when you serviced it? if so then this is a good sign and you should not drive it till you find out why it is slipping. Scan the tranny and check fluid pressure in various clutch packs to make sure within specs....especially the o/d clutch pack....it might be worn out

If fluid was nasty or brownish when serviced.....then soft components might be affected (rubber or plastic o-rings/pistons/soleniods etc) and make tranny act up. was there small metal particles on the magnet? any loose clutch material? Normal wear can put deposits into your tranny....which will be like a fine mud that sticks to your pan magnet...anything larger than grains of salt and you have issues


check the fluid level....duh but make sure tranny is warm and in park when you check it...some people overlook this.....im just sayin...

your description warrants a trip to the shop and have them scan the tranny and check...

good luck

 

what kind of trans? c6 aod 4r100??

 

The tranny fluid was in good shape. Color was fine and the normal mud was around the magnet, nothing looked abnormal about it.

The OD light was blinking before I did the tranny service, that is why I changed the OD selinoid (the one inside the pan). It acted like the truck couldn't make up its mind whether it wanted to go into OD or out of OD.

I had put a scanner on it previously, and everything checked okay then. I may try to see if I can borrow the scanner again and see.

I am just at a lost on this one. I drove it today to the store up the street and it drove fine. It shifts through the gears manually with no issues, but when I took it on the interstate the other day, is when it started acting up again.

How do I know which tranny I have? How can I tell?

 

should be an E40D

check the pan shape at http://www.yourcovers.com/transpan_9323.php

once you get your hand on a scanner...check all codes and clutch pack pressures...this will help a lot in narrowing down issues....

did you clear codes when you worked on it last? flashing O/D light would throw a code!

 

being that it is a 94 model it will be hard to get codes out of it or monitor pid data. it almost sounds like it is the converter trying to luck and unlock. when this happens once the od light starts flashing does it seem to stop "slipping"? still waiting to see what trans you have. that will help me narrow it down. thanks

 

Okay, I was able to check it and it is an E4OD. That is what I am thinking it is the Converter. Before this slipping thing and the OD light blinking, it would act like it was shuttering when you pressed on the gas, like it wasn't getting enough gas, but then the OD light started flashing and acting like it was slipping. When I did the tune-up, it acted like a new truck, but then it started slipping again, so I did the tran service. It acted fine for a few days and then back again, but the OD light hasn't come back on.

When I originally put the scanner on it before anything was done, I couldn't really pull anything except the OD pressure switch thing, which I replaced when I did the trans service.

 

sounds alot like a converter shuddering what is an od pressure switch thing???? what code did it give you?