Hi Y'all,

Long time lurker, first time poster. I have a 1990 F250 with a 460 and an E4OD. R, 1-3 all work great, but it doesn't shift to OD. The OD Off light/switch is operable. When on freeway, if the OD off bottom is not illuminated, it feels like it shifts out of 3, free wheels for a split second and goes back down to 3. When the OD off button is lit, all is good, it's just revs high in 3rd gear on freeway. Any ideas on what might cause that? Electrical issue or mechanical?

 

I'd be thinking mechanical.. I remember reading in a few places the e4od had issues with OD but I can't remember exactly what( bands or clutches I think), and if hauling with OD on it'd make the issue happen sooner. The OD off light should flash if there's an issue with something electrical in the transmission or if the VSS is failing.

 

I had this happen when coming north through D.C during afternoon rush hour. It's one of those places you don't want failures to occur. Fortunately I was able to get the hell off 95 at a ramp that happened to be right there. Once I realized what happened, I limped home to NJ doing 50 mph so as not to go into the overdrive. It was a very looooong trip. Ended up needing to have the trans rebuilt. $$$. Don't they always tell you that a "c" clip breaks?

 

Sounds like the OD clutch in the transmission has burned up.

 

Thanks guys. Sounds like a significant problem. I'll probably just live with the no OD. Not sure the truck is worth the time or money for a new/rebuilt trans.