Odd Transmission ???

[tsmith29040]

I tend to be ok as far as being mechanically inclinded, but this one i throwing me for a flip. 2001 Expedition EB 4x4 (5.4). While stopped in the center turning lane I accelerate to get across street into parking lot and I got nothing. Engine is doing everything normal but transmission is doing nothing. I go to neutral, then back down to low (or 1) and then it starts pulling again. I park come back a little while later and its driving fine. After a few minutes of driving I pull into another parking lot and it does the same thing again except this time nothing will make it start pulling again. I can feel the transmission changing gears, speedometer is moving as though its driving (funny thing it that the speedo is moving in every gear I select EVEN NEUTRAL) and I can not go back to park with out shutting the truck off in neutral with out it grinding on the park pin in transmission. Best description I can give is it feels like the transmission is free spinning.
I am lead to believe it could be an electrical issue? or possably a torque converter problem?
I will be impresed if anyone has some guidance on this one. Thank you greatly!

 

[trdragons44]

if you have somebody to help(and trust them). i would say go for a drive and when it starts happening one of you get out and look and see if the drive-shaft is turning. if it is its most likely something gone in the rear end. if not you might have a stripped slip-joint in the tail housing. or your transfer case is slipping into neutral some how. see whats going on and i might be able to help further.

 

[tsmith29040]

Thanks trdragon, after that econd time that was it. It longer moves. While waiting for a ride I checked everything I could on my on, and the drive shaft does not turn. You could be on to something with both of your thoughts. Could you explain the function of the slip joint in the tail housing? My dad also said it acted like the transfer case. The thing that bogles me is the fact that it made no breaking (for lack of better words) sounds, no popping, grinding, or anything. I am having it towed to a shop on monday and go from there. I cant tell you the last time I had a shop do a repair for me on a vehicle unless it was a warranty issue but this one is beyond me.

 

[trdragons44]

the slip joint is for when you go over a bump and the rear end moves up and down. the distance between the rear and the trans gets shorter and longer when the rear moves up and down. so a fixed/double flanged shaft would bind and break. so there is a splined piece that moves(slip-joint)... best image http://www.motorera.com/dictionary/pics/S/slip_yoke.jpg

 

[tsmith29040]

Ah,,, that was some what ignorant of me. I dont see that being the problem as I feel like I would have heard the splines strip. It made no unusual noises what so ever. The transmission just stopped pulling all together. Its going to the shop tomorrow since I have no clue as to where to start.

 

[trdragons44]

it could be as simple as a loose wire to a complete rebuild. let us know what the shop says.