OK i have a 97 f250 with 282XXX miles on what i think is the original trans. all my problems started when i towed a goose neck trailer with sticky breaks for about 200 miles one day with a Toyota 4runner on the back. but now i have a problem shifting out of first gear at all. i can hold the pedal to the floor or just hardly press it and it will just rev away. but no shift. now if i let it build up speed and let off the throttle completely then ease back on it it will ease in to second. once in second it shifts normal through all other gears. i have read that the valve body gives fits but i don't really know where to start. i am a mechanic by trade but i am NOT a trans tech. so any help would be greatly appreciated. i absolutely NEED to have this truck on the road. thanks in advance. Brannon

 

I'd really suspect your intermediate clutch is worn out. Given the miles it isn't a surprise.

The best way to diagnose is to manually put it in second and start out. If it tries to shift but not complete for less than a second and then shifts to second hard then that's pretty definitive that it's the intermediate clutch.

The transmission shifts from first to second when the common sun gear for the back two planetaries is stopped from spinning backwards. There are two ways this can be done. One uses both a clutch hooked to the case and a overrunning clutch hooked in serial. The overrunning clutch is there to let the transmission go to direct. When the transmission goes to direct the common sun gear starts spinning forward. So that overrunning clutch is there to let the sun gear start spinning forwards when the transmission is in 3rd or 4th. Because of the overrunning clutch, the transmission could freewheel in 2nd. To prevent this there is also a intermediate brake that stops the sun gear solid both ways to give compression braking. This brake is only engaged in manual second and comes on about a second after shifting and is released before shifting up or down. (That's why you feel a freewheel for a second when you manually downshift.)

By manually shifting you put both the clutch and brake on together so one is helping the other. If the problem is in the intermediate clutch it'll work fine in manual second. If it is a hydraulic or electronic problem it won't help to manually shift to second.

 

Unless you got the time and know how I'd get it to a reputable Tranny shop an get er checked out....

 

OK just drove the truck and manually shifting the truck just got me stuck in first gear. nothing would make it shift in to second. when i put the trans back in drive and let off the throttle it then shifted in to second gear. so this means i most likely have a hydraulic or electric problem. correct?

 

That's a weird one that I haven't heard before.

Is the O/D light flashing? The PCM makes the light flash when it thinks the transmission is slipping.

Is the speedometer working right? The same sensor on the rear end that feeds the speedometer feeds the PCM to decide when to shift.

 

Does not sound good.
Not shifting in to thrid or forth and no codes (thats was what mine did) This is called "safe mode" also referred to as limp mode. The transmission is essentially protecting itself from any further damage. The transmission is forcing itself to shift using pressure rather than the shift solenoids. I was told that this is normal when there is a problem and you should continue with your diagnosis.

The rear differential sensor is located on top. It is held on by a bolt. Remove the bolt and pull the sensor. If it is covered in metal shavings. Wipe the it clean and reinstall. The same goes here, inspect the connector and wiring.

You want to also make sure that the fluid is a nice bright red and does not have a burnt odor. If it is dark or has a strong burnt order, change your fluid, filter. If there is a lot of silver and shiny mud on the pan magnet then its usually toasted. I that is the case lets us know and there are a few pointer on repairs we can give you.

 

AutoTrans Articles - What is Limp Mode?

 

ok i scanned the truck tonight and it has no codes. the fluid is VERY burnt. and black. and not at all low. so i cuess it was just time. i talked to a diesel tech about it today and he told me that if there are no codes and it shifts in all other gears it was prolly the pump.bt i thought if the pump was goin bad then it would not shift good in any gear.

 

so i have decided that i am just going to get it built. and ideas if what i should do? DIY? send it to someone? i have a quote for a trans build that is said to be bullet proof for about $1800. is this good or can i find it cheaper?

 

283k on the origonal trans with the fluid and issues you have says rebuild to me. the only other thing i would suggest is try to start out with the tranny already in "2" if it still starts in 1st and is stuck then you have a sticking valve. you could try to flush the fluid and go from there but it sounds like you burnt your tranny up. 28k on an all origonal trans is really good.

1800 sounds a little cheap for a bulletproof tranny. a bullet proof converter will run you at least a 1000 dollars.

 

well this is a friend of a friend kinda deal. he said somethin like hardened input shaft, kevlar clutches HD tourque converter, and some other tricks new valve body and they weld up the bypass for the trans cooler lines so it bumps the flow to the cooler from 10 oz. in 10 seconds at idle to over 27 oz. in 10 seconds at idle. but like i said i am NOT a trans person so it could be a load of b/s but i trust my friend. he said that this guy is the $#!T with a powerstroke trans. e40d or 4r100 either one.

 

For 1800 bucks I think eer scratch that I'd be singing all the way down there my last tranny rebuild cost me 3300 and some change heck yeah that's a good price

 

hat wha i think to. and i have will have the money in two weeks. he also said that a stock rebuld would be 1200 so i really dont know how much more they are goin to do for 600 bucks. but i dont really care. i can get a ford reman from ford for 2000 and i am goin to be haulin a lot so i want more! dad always said if it broke then you need to upgrade.

 

You should have talked to a trans tech, not a diesel tech. Many diesel techs, like this one, don't know much about transmissions. You have a failed clutch(es).

 

Mark
I as many others respect your knowledge on trannys, but I was hoping that you would blow me out of the water on this one. You have before. Enjoy reading your post. Some of the best tech post I have seen. Sorry for the bump but I like reading your post and your fixes.