1993 F-250 extended cab 7.3 liter IDI non-turbo 2WD.

I purchased this truck nine days ago. PO had reduced price because he believed the tranny was making an odd noise in O/D. New price left room in my budget for a tranny repair, so I jumped on it. During the test drive, the truck did NOT exhibit the problem stated by the PO.

Two days later, the truck failed to start. Replaced glow plugs and fuel filter and got her back running. I believe this problem was unrelated.

Now I'm back on track, seeking the source of the 'tranny' problem. I'm gonna try to explain the situation, but I apologize in advance if I'm not clear:

The truck makes a sound (best way I can describe it is as a rattle) when shifting into O/D. This sound usually lasts a couple of seconds, and is accompanied by a mild vibration. I don't sense any significant loss of power. The rattle will cease immediately if I back off the throttle just a touch. If I am traveling uphill, the truck will still accelerate.

As to the nature of the sound, the closest thing I can recall is another truck I had years ago that had a stone guard on the catalytic converter. The guard would rattle very loudly at one particular speed. This truck has no stone guards, no cat and no muffler, though.

I have been trying to get a sense of where this noise is originating, and honestly when driving with the windows rolled up the source seems to be behind me. I would expect noise from the tranny to sound like it was below the seat. However, when the truck is climbing a hill and tries to shift into O/D it seems to oscillate between 3rd and O/D and there is an accompanying change in engine RPM's.

The O/D indicator on the gearshift lever is usually NOT lit, regardless of whether O/D is on or off. It does occasionally flash, sometimes rapidly. Also, the ABS amber light is on, and the brake module mounted on the frame rail behind the left front tire has a wiring pigtail that is disconnected. (I have not reconnected it as yet because I'm trying to remove all the mud from it first.)

As I mentioned, I've had this truck just over a week now, so I'm still learning it and finding new things to fix. I'm not sure what steps to take next to diagnose this problem, and any help y'all can give will be greatly appreciated.

Thanks!!

 

I don't have allot of experience with autos, but sounds like it might be a sticky valve causing it to "shutter" when shifting from 3rd to od. Not sure though.

 

If the OD light is flashing , you should have a code . Flashing indicates a problem .

 

Update: Cleaned and reconnected the pigtail on braking system. Amber ABS warning light is now off.

Pulled trouble codes with Innova OBD-I code reader. Got 23 (Fuel injector pump lever sensor input is out of self test range (Diesel)), 10 (separator) and 62 ((Trucks only) Transmission 4/3 circuit fault).

 

sounds like something with the torque converter. your rattle you describe could be made by the converter coming apart. that could also cause that brief shake/vibe your getting as well. and the time you say it happens is when the converter locks up. when you let off the throttle like you say the converter will unlock, that would make the sound and vibe go away. i'd take the inspection cover off and have a look at the converter.

code 23- did you hold the throttle at WOT during the code scan? if not then that is the reason for code 23. don't worry about it.

 

Ha! Newby mistake... yeah I forgot about the throttle position. Thanks!

After removing the inspection cover, what would I be looking for?

 

the dredged e4od shudder, get the thing to shudder then toe the brake peddle or turn on the 4 ways this will unlock the torque converter if the shudder stops..worn converter, some times when you have to many miles on the fluid it will do it..lots of diy fluid change threads on here...may throw excessive slip codes on some readers..if your speedo is bounceing may need to clean the sensor in the top of rear end,,VSS

 

Update: I had seen recommended elsewhere that the electrical connections to the transmission be cleaned. I gave that a shot today, with the following results:

Driver's side connector (shift position) - sprayed down the outside of connector prior to removal, then sprayed the female end extensively. Reconnected.

Passenger side connector - removed heat shield and sprayed down the outside of the connector. Tried to remove connector but it would not budge. Replaced heat shield.

Now I didn't expect that this would make any difference, especially since the posts I'd read said the passenger side connector was the important one. However, upon test driving the truck I found that the shudder problem was drastically reduced. When the shudder did occur, I tested it as recommended by speedwrench72 and the vibration stopped immediately when I pressed the warning lights switch.

Opinions, y'all?

 

Anyone?

 

Did you find any codes After your work

 

it sounds like a failing torque converter lockup clutch (code 62) because you have two symptoms that electrical issues alone will not cause (and iv never had with any of my code 62's)
a.the noise.
b.the shutter.

the second issue i notice,is that you probably need a new OD cancel switch.though it's not blowing the fuse,the wire in the column is likely chafed through.the light should illuminate any time you press the cancel button.not at random times.the fact it sometimes works and even flashes showing a code is set,means its not a blown bulb of course.
if the po left this issue unresolved,this tiny electrical issue right here,for under $100 and an hour's time spent,could have very well (and id bet $ on it) be the root cause your now failing converter,because it's been neglected by the po,it was left to dither between lock and unlock when it shouldn't have been thus resulting in the worn out lock up disc.
this is why it's extremely important to resolve any and all flashing od light issues with this trans,asap and not to drive the truck with it flashing at all if possible.

the solenoid pack plug located on the pass side of the trans has a clip you must carefully unsnap (do not use a screwdriver) to slide it up out.

code 62 even with the noise (wish i was there to hear it) and shutter,could still just be old/bad fluid and the reason it's having trouble remaining locked up when it should be,could still just be electrical issues.though it doesn't sound promising.
how many miles are on the trans?
how many miles on the current fluid?
what type of fluid was used last?

i would drop the pan,and pull the solenoid pack plug to clean it.
if you see a crap ton of deep black shavings around your pans magnet but all your gears show no sign of slipping,then that's more than likely the failing converters locking clutch all worn out.
then i'd replace the converter and give it some fresh fluid (mercon 5) clean all trans harness connections from top to bottom,replace the fipl/tps as 50k mile routine maintenance,replace the od cancel button/harness,clear the codes and go from there.

when climbing a hill,you say the truck is trying to shift from 3rd to od along with the noise and shutter and back and forth of rpms.that's not trying to enter od.that's the converter clutch trying to lock up (think of it as a manual trans clutch,but it's engaging automatically.) this is turned off any time the hazards are turned on,and this is what helped you find this particular "shift event."


don't be afraid to put E40D/trans issues in the thread title.it can grab our attention easier/sooner.

 

A lot of irons in the fire here... meant to update earlier but just now getting it done:

Truck has 185K on it, and AFAIK the trans is original. I have no idea regarding the fluid age or type, although fluid on the trans dipstick looks very clean. Fortunately the PO serviced the truck in a nearby town, so I plan to drop in and request the service records.

On a second attempt I managed to get the wiring connector loose from the passenger side of the trans and sprayed it out with electronics cleaner, then lubed it with bulb grease and reconnected. On the subsequent test drive, the shudder was almost eliminated. When it did shudder, it was while ascending a hill, and the shudder was not as bad - no lunging.

I have accepted the idea that the TC needs to be replaced, although I am still puzzled by the reduction in symptoms caused by just cleaning the electronics connectors.

Do you know of a good video showing the pulling and cleaning of this "solenoid pack"?

 

Forgot to add: After the plug cleaning, trans shifted much more smoothly.

Latest trouble codes: 11 (pass), 10 (separator), 62.

 

no video i know of but it sounds promising.

to help solve the puzzle for you as to why cleaning the connector helped resolved a lot of the issue,think about this:
what happens when something electrically controlled,doesn't get a clean signal? think of shutting on and off a light switch in your house quickly.what your doing is breaking the connection between the power source and the light bulb right? though a bad connection isn't a switch,it's acting like one,breaking and making a connection repeatedly.with a poor connection between the ecm (electronic control module) and the solenoid pack in the trans,it's as if someones switching off and on the lights in your house.this is why its vital to keep these connections clean.
it was a poor design.more modern vehicles all have electronically controlled engines and trans of course,and don't have all these issues.what i did was rtv the sucker right up to seal it.
you want to clean not only the plug,but down in the solenoid body - trans side as well.
what i did was put the tube on that comes with the can,and filled it.let it flush for a few seconds,then i left it sitting in there for 10 mins,then i soaked it up.that's when i hit it with grease down in,and black rtv outside once it snapped back in fully.
sure i may have fun removing all the rtv,should i need to get in there again,but if it does it's job well,then it wont matter cus i wont ever have to lol.