Had a front seal leak on my 2000 F250 V10 with 122000 miles. Since I've towed for years and the tranny had to be pulled I opted to just rebuild the whole tranny. I had problems from the beginning where it wouldn't shift into third and when I took my foot off the gas it would just go out of gear completely and just rev. After I stopped and started over, it would shift fine for the rest of the day.
Finally the O/D stem light started flashing and the mechanic did something to fix it. Since then it has shifted fine but when it went into overdrive the rpm would bump up and kind of slide into overdrive. Left the truck with the mechanic again for two weeks and it's better, sometimes revs and slides into overdrive not every time though. My problem, besides the overdrive shifting, is it now takes forever to shift in to 4th gear. I have to take my foot off the gas to make it shift into 4th and overdrive won't kick in until 45 MPH. My gas mileage, while bad enough before all this, has now dropped another 2 mpg to around 7.5 to 8. I was thinking about taking it to a Ford dealer for some kind of anaylsis.
Any help appreciated

Howard

 

Fourth gear IS overdrive. It doesn't shift into 4th and then overdrive. One of those "shifts" is actually the torque converter locking.

It sounds like they did SOMETHING wrong. Just what is wrong I don't know.

 

If I remember right Mark the OP rebuilt it himself..

 

It is hard to diagnose something like this without being "hands on" to see and feel what is happening, but given your description, I would start with the valve body. Check all the solenoids and check to be sure that a valve is not sticking in the valve body. Did you, or whoever rebuilt the transmission, disassemble and clean the valve body? It could also be a failure to properly torque the valve body bolts. Over tightened bolts will cause valves to stick.

 

Sounds like a hydraulic leak somewhere. That leak could be just that...something bypassing(leaking). Or it could be something not operating IE: not closing/opening as intended. That could be due to dirt, debris or failure. Broken springs, ripped or warn lip seals, gummed check *****, separator plate to valve body is loose etc... the list can go on. If it comes and goes that's more conducive of a hung-up valve, broken spring (less likely), intermittent electrical device due to a bad connection or failing solenoid winding, something gummed up or debris floating around somewhere.
Hook up the pressure gauge and take it for a ride. Watch what the gauge does when the problem occurs. That will at least narrow down which circuit the problem is in. Get the specs on pressures. Maybe Mark has them stored in has head? If not get them and road test. I do agree with the valve body inspection as well as the solenoids. Not being intimate with your trans this is general trans trouble shooting info. A trans is a hydraulic pump. When the fluid isnt going where its supposed to or leaking from that spot it wont operate as intended just like any other oil pump

 

 

Thanks for the response guys. The work was done by a professional mechanic shop and he does all the local PD patrol car trannys so I figured he new what he was doing. Checking the pressures sounds like a good idea. I think I'll pay someone else to do it though.

 

Monitoring Line pressures and pulling codes if its electronic and throwing codes is the first steps in properly troubleshooting a trans. Thanks for the line pressure chart Mark.

 

Generally that's true. It depends on the symptoms. Sometimes something is obvious.

How many have you rebuilt?

 

i have a 2000 f250 4x4 7.3 driving down the road went around a corner about 50 tranny just stopped pulling fluid was fine temp was fine not hot rodding it just driving i towed it home
now starts and runs great throttle response everything works correctly on the truck
dropped the pan watched the gear selector change gears and move the valve in the valve body replaced fluid and filter even in the converter
no change so i pulled the tranny and replaced the converter went back to gether same thing

imput shaft sets correctly when turning the shaft output shaft turns transfer locks in and out


anybody have any ideas

 

plenty why do you ask? Slush boxes to Allisons no 5R110Ws...yet....

 

Im having a hard time understanding what your saying? Need more info...Trans ID, mileage, service record....Did you check line pressures? My first thought is the pump let go if Im understanding your post? A pressure check will tell.

 

The only automatic available in 2000 was the 4R100.