My transmission was rebuilt by Ford under warranty for the CDF drum issue. I have not had a lot of time to drive it in the last month since I got it back, but around town or in-town freeway driving it has been perfect. The other night I had to deliver some equipment a little farther away and thought "Hey let's take the truck." On the ay there, keeping the cruise set at 79 mph, it was just fine. On the way back I set the cruise to 82, and after about a minute like that the transmission began hunting gears. On the gear display it would go from 10 to 7 to 8 to 1. Sometimes it would be in neutral during these (especially 1). I began to pull over, but once the speeds dropped below 80 it shifted into 10 and worked fine, so we kept going, just slower. Then I looked in my rear view and saw smoke, so I pulled over. I could smell ATF, and burned ATF. Looking under the truck I could see the trans has vomited ATF out all under the truck, including on the catalytic and the exhaust. I watched for a bit and saw it was not continuing to leak, so decided to see what it would do. We made it home driving no faster than 75, and once home I found no new leaks. I have a call into the dealer to get it back in under the rebuild warranty, but what are the collective thoughts about what happened?

 

My first thought is they overfilled the transmission with fluid, as filling seems to be a very delicate process. It got finally up to temperature on initial drive, and showed it's ugly side on way home. I'd likely simply take it back to the shop, explain your observations, and let them diagnose. Seems sometimes people can go in with a mindset, offer suggestions, and everything goes down a rabbit hole. Good luck!

 

had a very similar experience after a rebuild. Only in remote Utah of all places. No shifting issues, just a spike in temperature, and fluid ejected from the top vent. Never having seen the bench rebuild fill method, but it can happen, and if the shop doesn’t do an in vehicle hot level check you have this happen. I was lucky, one station at a crossroad, one lift, and a mechanic with some sense. Wish I had checked it myself.

 

I had no temperature spike, nor any CELs. Would an overfill condition cause the gear hunting issue? I can see how it could cause fluid to be thrown out.

 

No CEL on mine either. No thoughts on gear hunting, didn’t experience that. Document it with the service department and have them do the in vehicle full temp test to verify level. After the fluid burp, mine was back to normal. Truck and camper were a mess, took a couple of car wash cycles to get the smell and oily mess cleaned up. Best wishes.