Hi guys!

I've done a lot of reading on FTE as well as other sites trying to find out exactly what is wrong with my truck. I'm seriously starting to believe the trans is fried but I just wanted some additional (expert) opinions.

My truck is a 2000 F-350 SD 7.3 Diesel. It only has 51k miles on it and has been babied since day one. I have flushed the trans fluid twice in the 51k miles (1st time at 22k and 2nd time at 42k). Both times the fluid was nice and clean with hardly any metal shavings in the pan and smelled nice and new. I have only towed with the truck once and it was only a small equipment trailer with a garden tractor on it. I have also used the truck to plow two driveways for the past 3 seasons. Both very small driveways and I always took it easy on the truck.

A few days ago I went out to clean up the driveways after a snow storm (in Connecticut) and after pushing snow off to the side of the road, I backed up and tried to drive back up the driveway and the truck had no power with the gear selector in the drive position. Initially I felt like it was spinning in the snow but that turned out not to be the case. After experimenting with it for a short time, this is what I have discovered:

Moving the shifter from neutral to drive doesn't make much of a difference. If I rev the engine (in drive) the truck will just slightly start to move forward but barely enough to move the truck. With the shifter in 2nd, I get the same results. If I put the shifter in 1st or reverse, everything seems normal. The "OD off" light is not flashing.

From what I have read, it sounds like the over-drive one way clutch (or sprag) is broken. Does that sound correct? If so, am I in for a full rebuild?

Is it really possible that a truck that has been babied and has such little mileage on it could have a smoked transmission? If so... WOW!

I appreciate ANY feed back - so thanks in advance!

 

yes very possible. maybe your trans range sensor? im not a trannie guy...whats it do with the gear selector in 1 or 2?

 

Suzuki0702, thanks for the reply!

With the selector in 1 the trans engages and moves the truck normally. Same thing in reverse. However, if I put it in 2 I get the same behavior as in drive (D) - where it doesnt really engage unless you rev the engine and if you rev it enough it will just barely move the truck.

Do you know of any way to test the range sensor?

 

fluid level is correct ???

 

Fordfanatic4life:

I checked the level and it looks perfect. Also, the fluid is nice and clean and does not smell burnt or anything.

Its real odd that the trans is having trouble given that it has very low mileage (51k) and has never really been worked. Also, the trans acted fine up to this point. There were never any shifting problems or noises or anything. Just all of a sudden it won't move in drive.

 

well if it is down for the count, its REALLLY unusual.. judging by ur details that tranny has had a pampered life so to speak..

but we all know how princess's can be, hahaah..

hate to say it, but u might just be unlucky enuf to have a bad tranny.. now how bad the situation might be is hard to tell.. it might just be a valvebody/solenoid problem.. or it could be a biger issue.. but with ur fluid looking and smelling fine i suspect it isnt..

u sure the linkage isnt just mesing with you ??? perhaps its not gonig into gear properly ???

 

sounds like something electrical,maybe Mark will stop by

 

I would suggest changing out the solenoid pack. I seriously doubt something has broken,but who knows. On vehicles I've seen with lower miles, the solenoids somehow get stuck in them. Changing out the whole pack isn't that hard and is a shotgun approach because it has the EPC solenoid, tft sensor and shift solenoids in it.

 

Thanks for the response Chris! I found some instructions on how to replace the solenoid pack and your right - it doesn't look too difficult. I'm going to look at pricing for the solenoid pack and probably start there. If replacing it doesn't help I will probably limp it down to the local trans shop (about a mile away) and see if they can diagnose it. I really hope the trans is not shot after only 51k easy miles - Super Duty my @ss!

My old 1980 F-150 had over 200k on it and was used for plowing commercially for 14 years and the original C-6 still worked like a champ!

 

If it wont move in drive or second then its a mechanical failure inside the unit.

The forward and reverse engagement is done through routing fluid through the manual valve, from that point on its the solenoid block that regulates the fluid pressure and controls the shifts.

Most of the transmission failures I see come through the shop are a part failures, the fluid condition and maintenance record are almost never a factor. My own transmission has failed twice under 50k and both times it was a part failure, and unfortunately I had to put the same part back in because there is no update for that part. You can change the fluid in your transmission once a day and it wont prevent a part failure.

You can just fix what broke and put it back together, but the problem comes from the shop that does the work will have to give you a warranty, and they will want to rebuild the whole unit to help it last as long as possible and to make the return for that kind of repair. We do those transmissions with a converter and some hard parts for around 2k to about 2.5k, with a one year warranty.

 

I'm with chris on this, it sounds like the trans is having a brain fart. When you manually select first gear, the trans has nothing to think about and goes into gear. When you put it in drive or a higher gear, perhaps fluid is not being routed to only first gear and is being sent to multiple gears.

 

did you have cooling radiator for transmission?


Did you ever stop when shift in direction? or little moving then shift?


This alway happened all time on 2001 F250 with 5.4L that have plow. no one would stop then shift they would moving like slow then shift and you hear bang.


transmission alway go bad if you use truck plow snow.

 

If the trans. is slipping it may be the torque convertor. The trans. shop will let you know for sure. By the time you replace the parts you think may be bad, you could just take it in and have them diagnose it.

 

WOW! There sure is a LOT of bad advice in this thread! Torque converter? How does the torque converter know to work in manual 1 and reverse and not work in D or 2? Fluid only sent to 1st gear in manual 1, but several gears in other positions? It's clear that people that HAVE NO CLUE HOW A TRANS WORKS LIKE TO DIAGNOSE TRANS ISSUES!

There's no shame in not understanding automatic transmissions. Just don't tell people how to fix them if you don't know how they work. Maybe I'm being a bit nasty about this, but some of these solutions clearly don't have a clue.

jk080 is right. There is a mechanical failure inside the trans. If you'd like to spend money on a solenoid pack or a torque converter, be my guest. After they don't help your problem the trans will have to come out, get torn down, and the broken parts replaced.

 

Thanks Mark! I'm sure you are right. In my frantic internet search for a solution (probably about 6 hours yesterday) I have come across a few posts on other sites indicating the MLP or Trans Range senor being the culprit. The explanation is that the sensor can malfunction in a way that tells the PCM that the truck is still in neutral even when you have shifted into drive or 2nd. According to these other guys, the PCM controls the fluid pressure in the trans and since it thinks the truck is still in neutral, it doesn't build enough pressure to move the truck when you are in drive.

Of course, I would love for my problem to be caused by a $50 sensor rather than having to rebuild the trans at over 2k. However, based on my own experience as well as your comments, I am much more inclined to agree with you that something is in fact broken inside the unit. I would think if it was a sensor failing I would have a flashing O/D light or check engine light indicating that the computer has discovered a failed sensor.

With all that said, do you have any thoughts on the MLP sensor suggestions?