Ok, I'll try to be as "to-the-point" as possible.

'95 F150 sc
302
4R70W
90,000 mi.

5 months ago, after driving several hundred highway miles, I got off the road for gas, etc. From a dead stop, the tranny was hangin' on 1st gear. It would eventually drop into 2nd. No clunks or other strange sounds. I finished the trip (another several hundred mi.), stopping frequently and having the same thing repeat itself each time. Cruising at 70-75 mph, it ran fine. Only during shifts from a stop did I have this trouble. I made it home. The next day, the problem continued briefly, and then it never happened again.
In Feb., I drove 1300 miles to a worksite. No problems whatsoever with the tranny or anything else.
Yesterday I drove 400 highway miles (70-75 mph). After getting off the highway, the problem from the past surfaced again. It seems worse this time. Hangs in 1st...eventually shifts, but sometimes into 3rd, back to second or first...all over the place, really. Just can't seem to make up its mind. Again, once I am up to highway speed, I cruise with no problem. ATF is fine, just as it was the first time around. The previous owner took immaculate care of the truck, and the tranny has been serviced in the past.
Today, while driving it flashed a code. First I have seen this. Took it to FORD. Result: Code 628, excessive torque converter slippage. Ford says I need a new converter, and the dealer will be happy to do this for $640.00 I always thought that maybe the valve body was the culprit (I know they suck...it's on my list of parts to replace)...that maybe when I first had the problem, some debris had gotten in there and messed something up, and then worked itself loose and fallen into the pan. Now I dunno. I talked to a couple mechanics after getting the code read, and both were skeptical that it is the converter, based on my description of the problem. One tranny guy said that there are many things that could cause the symptoms I described, and he was leaning more towards an electrical/computer problem (he mentioned solenoids). I'm taking the truck to him tommorrow morning. If it IS the converter, I'm not doing my tranny any favors by driving the 50 miles to have it looked at by this guy. But I don't have much choice. He's the closest around, and was highly recommended by a mechanic I know and trust. Anyone care to throw in their 2 cents?
On a side note, yesterday was my birthday. I drove 400 miles to visit my folks and turn around and drive back the next day to work. Happy Birthday to me

 

Ok, so nobody wants to talk to me

A few minutes ago, I went to a shopping center parking lot to check things out. I accelerated slowly, I floored it, I shifted 1-2 manually...no matter what I did, the tranny went thru all the gears flawlessly. For the time being, 2nd gear is alive and well. It is obviously not gone as appeared to be the case over the past 3 days. Tough to figure. Something in the back of my mind keeps telling me it's a valve body problem. Maybe the 2nd gear valve is sticky. I know it could be other things as well. Maybe I should torque the VB bolts. I have read that loose bolts can cause problems.

Still flashing a code on the OD light. Does this continue to flash even after a problem has resolved itself? Does it have to be read again in order to clear it?

 

A slipping torque converter won't prevent the transmission from shifting. I think you can eliminate the torque converter as the source of the problem.

The most likely culprits are shift solenoids, the vehicle speed sensor, or a sticking valve in the valve body.

Since the light is flashing again the PCM has detected a problem since the last time the codes were read.

 

I think Mark is on the right track here.Lets us know what the verdict is..And we ARE listening just dont know what the answer is yet...

 

Thanks guys. I'm in agreement with Mark too. It's an intermittent problem. Today it's back to 1-3 shifting. Going to take a while to get to the bottom of things, because I am working a lot of hours. I'm also at a disadvantage since I'm working out of town, living in a hotel, with no access to a garage or a mechanic I know. I think I'll take it to the local Ford dealer, have the codes read again, and have them change out the tranny (and converter) fluid and torque the valve body bolts. It's a good bet that they need tightening, as I have read that this is a common occurance, and that loose VB bolts can cause erratic shifts in these trannys. Hopefully I'll get to it this week if I can find some time. I'll let you know what turns up. Thanks for the input.

 

Went to a tranny shop today and pulled the following codes: 621, 622. One is for the shift solenoid and the other is for the converter solenoid. Pulled an older code (from last week) of 628 for the converter clutch. After driving the truck, the tech agreed that it didn't behave like a converter problem. No other codes showed up. He told me that there is one shift solenoid in the tranny. It is a dual pack w/ 2 solenoids in it. Cost is $97.00 for the part. The converter solenoid is about $65.00. I was thinking of having just the shift solenoid replaced, mainly to see if that was the problem. If not, I'd go back and have the converter solenoid replaced and see what happens.

The solenoids come from Albany, NY, about 150 miles away. The tech told me that's where they are built. Could be remanufactured, I don't remember exactly what he said.

Comments anyone?

 

I'd be thinking that this is a heat related problem. And that *could* be a solenoid coil that opens when real hot. OR it could be a valve body that is changing its dimensions when hot... The odds of a solenoid opening its windings are small... very small. The odds of the valve body binding are a lot higher. Too bad you are 'on the road', cause you could do your own work on the valve body. Kinda messy... and a pain to get the old gasket off. But if you did it, you know that it was done...
Check the wires leading to the side of the trans and make sure that the connector is tight, and the wires not touching hot surfaces on their way down from the ECM. One other thing to try is Lube Gard from you local NAPA or other source. MAKE sure you get the right colored bottle for your transmission. It is the only one recommended by the manufacturers. I get no kickback. I used it on my AXOD and now have 215000 miles... 16 years... Made the servos apply more evenly.. It can't hurt, and may free up the valve body
tom

 

I initially thought about heat as well, since the 2 times that this problem has occured has been after driving several hundred miles. But in between these times I drove 1300 miles in 2 days without a problem. The most recent occurance came after 400 miles. I'm still thinking of a valve body problem as well. Could be a sticky valve or accumulator problem. I want to put a Lentech VB in it anyway, but wanted to wait till I was home so I could do it myself. I guess I'll be seeing the local Ford garage this week to have them check the ECM/tranny connections. Maybe I'll get lucky. Maybe it's a bad connector or a short someplace. Maybe it is just a matter of replacing the shift solenoid. If not, maybe a new VB will be next. All I know for certain is that I'm gettin tired of drivin' a 2-speed w/ OD. I'll post here again when I know more. Thanks

 

Went to Ford today. PCM conections look to be in good shape. Neutral/safety switch checks out ok. The tech got on the phone to tech support and found a TSB for the accumulator from '97. Symptoms of accumulator failure are just what I'm getting...erratic and extended 1-2 shifts. $20 for the part, it's been ordered and will go in next week. Mighty curious to see what's in the pan when we drop it. I don't expect to see much, but at this stage I won't rule anything out. Naturally, after I drove the truck off the lot, it shifted perfectly for several minutes. The truck's possessed and gets great satisfaction in messing w/ my head

Kudos to Plattsburgh Ford in Plattsburgh, NY. They let me hang around.... no "we can't let you out on the floor due to insurance issues" crap. The tech was great, and everyone else was helpful and laid back as well. Nothing worse than being cooped up in a waiting area while somebody you don't know from Adam is pokin' around under the hood of your ride.

We'll see if the new accumulator takes care of the problem. I still have my doubts, but it won't hit my wallet too hard to find out.

 

Now that you say that, I think I remember reading about some trouble with the intermediate accumulator regulator valve, and it causing long 1-2 shifts. Let us know how it turns out.

 

Time for an update. It appears that the accumulator assembly was the culprit. After installing the new unit, it shifts perfectly. I can't get it to hiccup.
Now, there WAS some metal in the pan. Mostly very fine dust, most of which was on the magnet. There were some larger shavings, I picked maybe a dozen or so of them out. When I say "larger", I'd say that all of them together would probably cover the surface of a quarter. Maybe not even. There were a number of in-between sized shavings as well. All together, I'd say that the amount of metal in the pan would fit more or less on a tablespoon (realizing of course that there are more particles floatin' around the tranny). I wasn't nearly as concerned by this as the tranny tech was. He asked me if I wanted to proceed with installing the accumulator. The dust doesn't bother me. Normal wear and tear. The other pieces...well there sure wasn't a lot, and with 92K, I would expect to maybe see something like that. Maybe I'm wrong, I'm no expert when it comes to trannys. I do know that they're built to eventually fail, but I don't think I'm there...yet.
In any case, since it was on the rack, I also had the converter drained, and a new filter put in. I'm guessing the last service was probably around 50K. $200 later, I'm motorin' again. The tech seemed a bit surprised that it shifted fine after all was said and done. Time will tell, I guess.

 

Well, before anyone says anything about my previous post, I'm afraid to say that there are still problems. I don't have time to go into the particulars, but I will post when I have time, prolly tommorrow morning. Ugh.

 

I think you should be concerned about those shavings. I'm not a tranny expert by no means, but I don't think that is normal. I'm in the process of rebuilding my E40D (168,000 miles), and I haven't seen any "pieces" of anything. The magnet had some fine dust, and all of the parts had a super-fine black haze, but that was all. I believe most of my problems lied in the converter, but I firgured the rest of the tranny was "due".

 

Could be right, Andy. The accumulator was not the fix I had hoped it would be. Here's what the tranny is doing after the new accumulator:

Occasional missed 2nd shifts. Not as often as before, mostly when it's cold.

Somewhat rough downshifts from OD to 3rd when coming to a stop. I can feel the downshift much more than before.

A slight vibration just before a complete stop as it goes into 1st.

In OD, I can't get passing gear. It stays in OD. Sometimes it kicks down, but there is a dissconnect. The engine revs, and it sounds like there is no link from engine to tranny. Other times, it behaves perfectly.

That's pretty much it (that's enough...ugh). I dunno, could be a much bigger problem here. I have spent about $300 in diagnosing and trying to correct the problem. To spend more $$ trying to figure out what's going on is getting tougher to justify. I could be putting that $$ into a new tranny.

 

GB: Shifting is controlled by the PCM using inputs from the throttle position sensor (TPS), vehicle speed sensor (VSS), tranny output shaft speed sensor, and brake light circuit. The PCM then operates the 2 shift solenoids, the pressure control solenoid (EPC) and the converter clutch solenoid.

A malfunction in any one of these items, or their connectors and wiring, can cause havoc with shift behavior and lots of wierd stuff - for instance, if the wire between the EPC solenoid shorts to ground, the tranny line pressure goes to minimum, and it will slip so much you will think you are in neutral.

You can throw parts at the problem, but you or your mechanic need to systematically track it down. Ford dealers generally have diagnostic equipment that can monitor transmission operation and control.

Of course, all the above ultimates provides control inputs to the valve body, so that your problems could be hydraulic or mechanical, but the great majority of problems with these trannies originate in the electrical parts.

You need to have the Ford electrical book for your truck, but the first thing I would check would be all the wiring and connectors involved, including the PCM connector. Damaged wiring and corroded connectors are a major cause of intermittent problems. And don't forget the grounds, especially the one used by the PCM.

Good luck!