Posting to you now 200 miles from home up a canyon... Stranded. Here's the background information:

I was not driving the truck, I had charge of the food vehicle (Land Cruiser). My dad was in the truck, towing a vehicle on a trailer, 6,000lbs total load tops. Came to the road up the canyon. 13% grade for seven miles. Dad put the truck in 4-low but didn't lock the hubs. Climbed the worst of it just fine. Pulled over for about 15 minutes once it leveled out to change back to 2-high and let things cool. Started into the last two miles, a much less intense grade. Here's where things went wrong:

Only 1/4 mile from the cabin, dad is going slowly up the road with the lever in the "1" position. *All behaving normally up to this point, no slipping or anything.* Once the tach got high enough, dad shifted to "2." He says he thought he may have heard a "pop" sound but isn't quite sure, and instantly lost all power to the wheels. The revs jumped as if it had been shifted into neutral. He pulled over and parked on the incline. I came back at this point to help and figure out the trailer situation... Anyway, the truck only moves in reverse. D, 2 & 1 all behave like neutral. But neutral behaves like Park; we can't push it, it feels like the parking stop is engaged!

We disconnected the trailer, towed it with the Land Cruiser, and reversed the truck the rest of the way to the cabin... What a sight.

So. I don't know what to think of this. I hope and think it's not a mechanical failure, given the way it just failed instantly when operating the lever and the fact that N is now P. The fluid isn't hurned. Electrical? Assistance needed ASAP! Thanks in advance!

 

does the truck have a transmission mounted brake. did you check the transfluid. try shifting the truck at the transmission see if you get all of the gears to select. and look at the linkage to see if it is bound up. since it was being manually selected it sounds like a linkage issue you may not be able to see the issue but verify that the manual selector is able to move were it is supposed to.

 

No trans brake (if you're referring to the e-brake). Fluid is fine. I haven't played under the truck yet, but I did mess around in the cab. The linkage may feel a little easier to move, but I can't say for sure. The weird thing is, when I rev it in D, 2 or 1, it revs very freely and takes longer to settle to idle than when I rev it in P or N.

 

that sounds normal as far as the idle down time transmission should not be trying to move in neutral or park. i would verify that the shift linkage moves through all the selections and has good contact could be visual on the outside could be an internal problem you would have to most likely pull the pan to inspect. by the way sorry if i missed this did not catch what kind of truck it is what engine transmission. have you tried to torque brake it in forward gear. and try checking the trans fluid with the engine cold and not running as compared to a hot idling engine.

 

In my haste I forgot to specify that this is an F250, 7.5L with the E4OD.

 

thank you for the information just wanted to know a little about the truck.

 

Just played with it a little more. It only starts in P and N, which suggests to me the linkage is ok.

Tried revving with the tcase in neutral. When I put it in park after revving in reverse, I can hear the parking stop grinding. But when I put it straight to park after drive, no grinding. The output shaft isn't turning when the tranny is in forward.

I noticed, with the tcase in neutral, when I rev it in R it takes the revs a second to settle down, as if there is inertia behind the flywheel. It behaves the same way in drive. As if there is inertia behind the flywheel. What I'm suspecting is somewhere right behind the output shaft is a failure of the forward system.

 

well could be the forward clutch assembly or something has come apart unless you put it in park it should not be trying to engage park all it is is a lever nothing mechanical or electric unless something did come apart and the linkage is not off at all and the fluid is good then this suggests a mechanical failure other than trouble codes and testing the forward components for mechanical function and controlled function. with out being able to do testing to verify this just do a good visual inspection of what you see. how is you transfer case shiftier can you engage it and dis engage it.

 

Transfer case shifter works fine.

What I still don't understand is why it won't roll in neutral.

 

how were you trying to push it with a pusher vehicle

 

Tried to push by hand. Down hill.

 

jack the rear end up and see if you can spin it by hand. unless something came apart which i doubt because it still has reverse then other than trying to push it the opposite direction i would manually shift the transmission at the transmission. have you ever been able to push your truck before.

 

Looking at the E4OD clutch application chart, If I had to guess, you grenaded the intermediate one-way roller clutch. Somewhat common problem on E4ODs, and very common problem on early 4R100s with the intermediate sprag-type clutch. They almost always blow up on the 1-2 shift, especially at high RPM.



Also, I think running it in low-range was a bad idea. 7 Miles up a 13% grade in low-range is a lot of stress on the planetary reduction in the transfercase. That's something it was never designed to do, and it's likely the transfercase (and transmission) got very hot doing that. I'm not even 100% sure the torque converter actually locks while in low-range.

 

For what it's worth, it wasn't in low range when it died, but I'm sure after a climb like that it didn't matter. I don't think the tranny overheated though, the last time it did it barfed fluid out the vent on top.

Kinda pissed but not surprised to hear about the clutch pack. I always knew the tranny would be the first to go; my friend's e4od has been rebuilt four times.

 

Not a clutch pack, intermediate one-way roller is what I think failed.

Also, if your friend has had his E4OD rebuilt 4 times, he better find a new shop because they're doing something wrong. My buddy has an all-original 176,000 mile E4OD behind a turbocharged 460, and it's just fine...