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'97 Powerstroke shifting struggles

8K views 51 replies 5 participants last post by  themule67 
#1 ·
I thought I had this problem fixed but its back.
1997 Powerstroke Diesel with 358k miles and auto transmission.

Starts fine in warm weather. Long starts in cold weather. Injectors have not been checked nor has glow plugs/relay. Always has white smoke when it starts

After it starts, 1st gear is fine. 9 out of 10 times it shifts correctly for full 114 mile round trip. But 1 out of 10 times, it won't shift into 2nd. I can use the shifter to put it in 2nd. Runs fine. Use the shifter to put it back into Drive and it revs high but is in 1st gear. Won't shift into 2nd or anything else.

Seems to occur when I drive over rough rode or am on a hill. But maybe that's just coincidence.

Have had the trans flushed and new filter put in. Made shifting somewhat smoother. No grit or shavings in the fluid. Fluid not milky.

Have replaced the Transmission Range Sensor. Seemed to clear things up for a few months. But now the problem is back. This is the 8 flat pin connector.

Have cleaned out the Exhaust Back Pressure Valve. Was sooty. Did not remove the line and clean it.

Took the truck to reliable Transmission guy and he drove it. Said he doesn't think it is the transmission. Says its could be one of the sensors or wiring harness issue or any number of other issues but does not believe the transmission is the problem.

Said he felt it would be a waste of money to pull the transmission until I had looked into other more likely issues.

Today I drove it 20 miles and it shifted fine. Stopped for 1 hour. Got back in and drove 9 miles and after a red light, it refused to move out of 1st gear. Only went into 2nd if I used the shifter to put it there. Drove back through town, stopped at a stop sign and then a red light. As I drove back to borrow another truck for hauling (driving back 9 miles), it shifted just fine.

If it is a wiring harness issue, how do I figure out where the problem is?

Would injectors/plugs cause this issue?

Perhaps I should be looking at the transmission solenoid?

I don't have enough wrenching expertise to know what to do... any recommendations would be appreciated.
 
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#2 ·
Have you had it scanned for any codes maybe there are codes stored that would help diagnose the problem.I would try replacing the speed sensor in the rearend. They are inexpensive and I know they can cause shifting issues buy it from ford not your local part stores also, check the pigtail connector for the sensor. That is what I would try 1st. Hopefully, mark our tranny guru will read your post and give some insight into your problem. Themule67
 
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#3 ·
I never have a flashing OD light, but when I have it checked for codes it is always something to do with 'left bank' or 'right bank' glow plugs. I have the codes cleared out. Seven days later when I haul again, I have the codes checked. I get the same codes although I never have the flashing OD light to indicate there is a problem.

I wondered about the speed sensor, but my speedometer needle is steady not bouncing around. I'll check the dealer and find out the cost.

I'm definitely going to use the multi-meter this next week while the weather is warm and see if there is a glow plug relay issue.

I did one other thing... I also unplugged the third backup light (cargo light) above the rear of the cab. Just in case that was causing something to go wacky.
 
#4 ·
I think the last time I bought one it was like 40-50 bucks. The last time I got one from napa the connector did not fit as snugly as an oem sensor that is why I suggested an oem sensor. Look closely at the pigtail connector for any bare wires I think I had a little over 400,000mi when I replaced the original sensor and the connector the pigtail is about 20 bucks. As for the codes for rt and lt bank you might be due for some new under valve cover harness's. When you unplugged the third brake light did you notice any heat damage to the plug or housing? themule
 
#5 ·
When I unplugged the light, the middle socket was melted. Only the left and right side of the 3 part light assembly actually lit up. I have a replacement assembly I pulled from another vehicle at junkyard but have not installed it yet. I just unplugged the existing assembly and screwed the lense cover back on so I could keep the elements out of the cab assembly.

My gut instinct (what little I know about this), tells me this is a wiring issue. It acts like a wire is shorting or maybe is not making constant connection. Perhaps I'm reading too much into when this occurs, but I would swear its right after I start down a rocky road that has a downhill incline.
 
#6 ·
What you could try doing is spraying the pigtail connector with electrical cleaner and smear a little dielectric grease on the connector and see if that helps. As for your 3rd brake light I had the same problem I actually had to break the housing into pieces to remove it because, it was so badly melted as well as the wires and plug. I replaced it and about 2yrs later I noticed it was starting to do the same thing so, I bought another good used one this time when I changed it out I replaced all the bulbs with 194's instead. I figured the bigger bulbs was creating to much heat as for brightness yeah, a little less but, that was 6yrs ago and I just checked it out a couple mths. back and no signs of any heat damage. Themule
 
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#8 ·
No, problem. Hopefully, others will chime in with suggestions. Don't forget to put the 194 bulbs in place of the original ones then you won't have to worry about the 3rd brake light again. Themule
 
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#9 ·
This is soooo sad.

This afternoon I had to return the truck I borrowed and pick up my truck. I went out of my way to drive to town (24 miles) to get gas and stop at autozone to pick up some dielectric grease.

I left autozone shaking my head in amazement.

Not one, but two guys working there each told me they don't have dielectric grease. They don't have anything to clean electric contacts. They stood in front of the transmission fluid, brake fluid, etc scanning the shelves and adamantly maintained they don't have any such thing there.

So sad. I had pulled up their inventory on my smartphone. They had 3 different types of dielectric grease on the shelf.

I left and went on to gas up the truck and pick up my truck.

The people in this world never cease to amaze me.
 
#10 ·
Sounds like two lazy young kids that did not want to be bothered. Themule
 
#11 ·
Hey! justwondering any news about the problem?
 
#12 ·
got the 194 bulbs and have two more warm days to get them in.
Also got the dielectric grease and contact cleaner (o'reillys) today.

Took the ford and it hard shifted then acted up again. Course I haven't messed with anything yet.

It was 70 not rainy. Drove over some bumpy road with the truck doing downhill. Everything was fine for the first 22 miles but it started hard shifting then stuck in second after the downhill bumpy road.

About five miles later it cleared up as I tried shifting from second back into drive with the shifter.

So I am planning on doing one sensor at a time and drive it to see what finally fixes it.
 
#13 ·
Hope you had a great x-mas. In your last response you stated that you plan on doing one sensor at a time. At least on my 95 there is only one sensor that can cause your symptom and that is the speed sensor in the rear diff. If you are planning on using the same sensor I would pull it out and wipe it off check for any metal shavings also, while your under the truck you can disconnect the harness plugs going to the transmission spray them with contact cleaner and smear a little dielectric grease on them and reconnect just to rule those out. something I remembered back in 2006 when I experienced hard shifting it was intermittent I had a bare wire in my passenger taillight that was touching at that time I had them replace the taillight socket pigtail and also, check the other side while they were at it solved the problem that time. To answer your ? from your 1st post your injectors/glow plugs would have nothing to do with your tranny shifting problem. They would however cause your long cranking times in the winter when it gets cold plug the block heater in see if it starts easier. What suprises me is when your truck hard shifts is that your OD light doesn't flash or set any codes. Every time mine has ever done that my OD light would flash and also, store a code. In the 10 yrs. that I have owned my truck I probably have had hard shifting problems 6 times most with different causes 2 times was the speed sensor issue either with the plug or the sensor itself. Keep me posted themule
 
#14 ·
Which scanner are you using to scan for codes ? Not all scanners will read codes on our trucks. I use AutoEnginuity with the ford enhanced package it will do anything a ford dealer can do. themule
 
#15 ·
Hope you get it, and check back with you did if successful please.I bought my 97 new and it did this from day one. At 7000 miles they replaced the entire transmission and that did not help. Thankfully mine only does it once in a great while, but it's been something I've put up with for 19yrs now.
 
#16 · (Edited)
Okay folks - the saga continues.

Today was a beautiful day (almost 60). Since tomorrow will be 40 and raining I decided to use my christmas present and work on the truck.
Yes, I know you will be jealous, but I got a brand new piece of cardboard (picture below) to lay on while I mess with the truck! Life is good....

Anyhow, the variable speed sensor sits at the top of the differential at the rear of the truck. For me, it was a 1/2 inch socket that fit the bolt best.

Visual inspection of the plug and harness gave me the following (picture below):
1. The plastic housing surrounding the wiring harness was compromised and someone had put black electrical tape on part of it. This tape was hanging loose and a green and red wire was showing about 1 inch from the back of the plug.

2. The half-round, rubber boot that covered the back of the plug where the two wires entered was sitting completely off the plug. No amount of persuasion on my part could get the boot back on the plug end.

3. I could rotate the rubber boot to the left or right and see the back of the plug where the wires went in-- very easily. This means that moisture, dirt, etc could possibly enter it.

4. The entire assembly (sensor and plug) sits directly under the bed of the truck where the gooseneck housing is located. Since my gooseneck ball can be recessed into the bed under a hinged flap, I noticed there is a gap on the hinge side about 1/2 inch wide. This opening is directly above the sensor and plug. So in addition to the dirt and road grime from below, I also have the rain, dirt, sand, whatever is in the bed of the truck draining onto the sensor from above.

CAREFULLY, I carefully wiggled the end of a flat blade screwdriver under each of the long tabs on either side of the plug so I could pull it from the sensor. I managed to bust them both. Brittle.... very, very brittle black plastic.

Moving on to the sensor itself. Piece of cake to use a 1/2 inch socket and back the bolt out of the differential. Had to use the flat blade screwdriver to gently, patiently pry the sensor up. Wiggle it and worry with it a bit and it comes right out. Looks like a round cylinder with a flat plate on the top.

There is no way I can get the sensor and plug separated without busting one or the other. I tried prying them apart, tried wiggling them, worrying them with channel locks but nothing worked.

I decided to put the sensor back in to keep rain out of the opening; covered the whole thing with a plastic bag; put my cardboard and tools up; come in and let you know whats going on; and search for the pigtail and sensor costs and part numbers before I purchase new ones of each.

I do need some way to deflect water draining from the bed.

I hope to have more to report after Tuesday or Wednesday next week depending on weather.

.
 

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#17 ·
Hey! justwondering checking in to see if you had any luck. themule
 
#18 ·
Going on my second week trying to get over flu, head cold, and sinus infection. We had wet and cold weather until next week so my plan is to pick up the sensor and pigtail on Tuesday while it is 63. I hope the sun is shining. Got my soldering iron out and heat shrink so I just need the sensor. Got a new bag of throat lozenges so it's gonna be great!
 
#19 ·
Good Luck! let me know how it goes. themule
 
#20 · (Edited)
Finally over this lingering sickness and a pretty day today. Called the ford house and got a price on the sensor 30.91 plus tax. Not bad. Then asked for the cost of the pigtail. They had to look it up and call me back.

I nearly had a cow.

They said the new pigtail connector would be 60 bucks plus tax!

I asked why a pigtail cost twice as much as the sensor. They didn't know. Said that's the cost in their catalog. 100 bucks to replace both.

I am going with a new sensor that's oem and will look elsewhere for the connector.
 
#21 ·
Got the VSS today (variable speed sensor). Did not buy the plug end (pigtail) since they wanted 60 bucks plus tax.

I did let them know that the pigtail connector is between 5 bucks and 15 bucks all over the internet. Could they please check to be sure they were looking at just a pigtail connector and not something with heatshrink, extra long electrical lines, etc etc. The Ford house would not even review the request. Said that the great thing about the internet and that their price on the pigtail was 60 bucks take it or leave it.

I left it.

Anybody have any bad experiences using a new plug from Standard, AC delco, Dorman?

Til I get the new plug, I'll install this tomorrow and use the old plug. Plan to customize a velcro sling for it to be sure it stays connected til I get a replacement.

I think I'll try my next purchase from the Ford House over in Sherman and leave this one in Paris alone... wow
 
#23 ·
Thanks Mark.
I removed the old sensor 1/2 inch socket for the bolt holding it in place.
Used dielectric grease on the new sensor socket and reconnected everything.
Used gorilla tape on it to keep it together til the replacement pigtail arrives. But I need to short haul round hay bales tomorrow so I can test this out while runnung my loads.
 
#24 ·
Okay --
Today I took the powerstroke to short haul hay.
First run, (30 mile round trip) was fine. Everything shifted in and out of gear just fine.

Second run (after 2 hour delay - had a flat on the trailer and after finally getting the lug nuts off and the spare on, followed by the obligatory 50 mile round trip to get a replacement tire and installation on the wheel - yes it had 8 lug nuts and no- none of my trailer spares have 8 , sigh)... second run everything was fine for about 8 miles then the rpms run high and it won't shift.

I slow it down, shift to second drive a short distance and try shifting to drive.
RPMS run high.
Down into 2nd, drive a short distance and shift to drive.
RPMs run high.
Third time, down into 2nd, drive a little bit farther than first two times and shift into Drive.
Very hard shift into 3rd.
Runs fine and shifts very smoothly for the remainder of the trip about 20 miles. Fine when I had to back the gooseneck down the drive. No error lights. No problems.

So the takeaway is that changing out the vehicle speed sensor did not fix the problem.
Draining the transmission fluid, changing the transmission filter, and putting in new transmission fluid did not fix the problem.

I was surprised that it did shift so quickly back into third. All the previous times, I would have to drive 25 miles or so before shifting into drive didn't just give me racing RPMS.
Was not raining. Was windy. Road was a rock road with some asphalt.

I'm thinking its still an electrical/sensor issue.

This weekend I'll be changing out the electrical third brake light (cargo light) above the truck bed. What should I try after that?
 
#25 ·
IT DID IT AGAIN!
I did three more short hauls of round hay bales.
First trip:
Smooth shifting all was good.
Second trip:
Smooth shifting all was good
Third trip:
Over was fine (15 miles), 2 miles into the return trip -- on asphalt I was accelerating and realized there would be some bumps up ahead so I momentarily (just 1 second) raised my foot off the gas and then changed my mind, so I continued to push down on the gas and it started again with high RPMS and went to 2nd gear.
I coasted to the stop sign letting the trailer slow me to a stop.

Waited for a moment for the 2 trucks (cross traffic) to clear.

Pulled out through my turn. Wouldn't shift out of second. I slowed down to lower the RPMS and tried again giving it some gas and it was a very delayed shift, very hard shift to 2nd.
Ditto for 3rd.

Then had no trouble for the remaining 10 miles home. Two more stop signs, eventually up to 4th gear (briefly), then backed the trailer into the hay unloading area. Shut her down, got my keys and walked the 1/4 mile to the house.

Previously I blamed this on bumpy roads or inclines, but I swear I was driving through one pasture to get to the hay bales and over washboard road three times without it failing. Then on the asphalt, smooth area it fails and seems to be related to indecisive acceleration by the driver.

What am I missing?
 
#26 ·
Just to rule out other possibilities, are all your brake lights working including your third brake light ? 1 of the 4 or 5 times that I have dealt with this issue over the years was caused by a bare wire touching in my taillights since you are driving on bumpy roads so often pull your taillights out and check the wiring on the pigtails pretty quick and easy to check just to rule that possibility out. When you can you need to replace that VSS pigtail to 100% rule out an issue with the pigtail and VSS sensor. The last time that I dealt with the hard shifting and shifting issues which was march of last year the problem ended up being with my instrument cluster but, we need to rule out all the other possibilities before we get into the inst. cluster which is a little more involved. Have you opened up your rear diff. cover and inspected the tone ring and gears for any damage. Jack up the rear end so you can have someone spin the tires while you closely look at the tone ring for any chips or damage. I had to do this last year just to rule it out as being the cause. Don't forget you still have my Ph# to call and talk if you want to. themule
 
#27 ·
Hey, justwondering any update on the shifting troubles.
 
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