The most mysterious part of this whole blown-tranny adventure... We can't push the truck! It will move backward when in gear, maybe with a struggle (I can't say, I haven't driven it since the incident) but when both the tranny and the t-case are in neutral, we can't push it! It feels stuck! What could have possibly happened??

We do need to figure this one out quickly; I'm hoping dropping the driveline will let us roll it, otherwise we probably can't get it on the trailer...

 

Which trans and what happened to it?

 

[double post]

 

E4OD. Blew all the forward gears towing a (relatively light ) trailer up a canyon. Forward is now effectively neutral. ...Except the truck doesn't roll. We tried pushing it DOWNHILL forward facing and it wouldn't roll.

 

Well with the t-case in neutral it shouldn't matter what happened to it. I'm wondering if the rear end didn't die and gear fragments are getting in between the r&p gears going forward but falling out going backwards. I've had this happen in heavy trucks. I guess it could happen in a pickup, too.

 

Wouldn't that problem go away or change after moving the truck? We reversed it about 1/2 mile up to our cabin, but it still is just as stuck when in neutral.

 

If that is the case and your F250 has a full floater rear end, pull the axle shafts out and that will let it roll no matter what happened.

 

Seems easy enough. What is involved in pulling the shafts? Opening the diff and removing the clips? Are there clips at both ends?

 

I drove a 78 GMC 9500 series about 4 miles backwards up a county road to get it to a safe location when the front read end grenaded. You could go forever backwards but as soon as you tried to go forward it would lock up in about 2 feet.
Go ahead and pull the drive shaft first and see what happens but it sure sounds like a differential problem. Or a rear brake problem?

 

Could it be the t-case if we did do a significant portion of the climb in low-range with the hubs unlocked...?

 

If it's a full floater the 8 small bolts on the end of the axle hold it in. Real simple. If it's a semi-floater yes pull the cover and then the clips. Messy but still pretty simple.

 

No if it was the t-case it would either be locked both ways or freewheeling completely. Or laying on the ground in 2 pieces. Well I guess if something came apart and was letting the shift forks float around it might lock going forward and kick one out going backwards. When you backed it the 1/2 mile was it still in low or back in high?

 

We shifted it back into high just minutes before the tranny blew. It's been in high since. Except when we tried to roll it in neutral...

 

Driving in low range with the hubs unlocked should make no difference. Driving in low range long distances can make a difference if you go too fast and overheat the t-case. Or if the oil pump failed that would kill it.

 

Pull the drive shaft and see what happens. At least that will let you know which end to work on!