Well shucks, the PSOM might be the issue. Since my last post on the 31st, I've taken my dash apart to get to the cluster. I found mouse scat in there which leads me to believe they urinated on my PSOM. I tried installing a different cluster from Pick N Pull but it was one from a 96... I need a 92/93. It turned on, tach worked and all but the wiring is different so some lights were on that shouldn't have been. Plus it said 295k miles instead of my 193k. However, since reinstalling my original cluster I've driven / towed my 5th wheel thousands of miles without a hiccup. My rear abs keeps coming on but w/e. Has the trans had any work down to it?

 

The speedometer/PSOM is swap able with your original cluster speedo/PSOM.

Yes when swapping in a 96 cluster into a 92 you will have to change some pins on the harness for the newer cluster to work properly.

The plug and play years are
92 to 93
94 to 95 1/2
95 1/2 to 96 and 97(F250 and F350)

 

There were 2 previous owners, and the last owner seemed to have used it as a farm mud truck out of Nebraska. I managed to find a record which showed the mileage, and it seems the first owner sold it at 20,794 miles, on 3-10-1997. Then it was passed to the previous owner, where he sold it in 1-03-2013. The truck was bought from the dealer a year later from us. The record states EXEMPT, and it's probably because the truck was over 10 years old. From my math, till the time it was passed to the dealer (the mileage when bought from us was about 130000), that means the truck was driven about 7000 miles a year. For a Nebraska farm truck, I honestly think it should have many fewer miles than it does now, but from the amount of abuse it took, well, can't say. Even if it was a daily driver, at worse it could be at 200,000 miles, so for what ever reason it may of been changed, I can't say, nor can I really guess the mileage than what its at right now.

And 92F2, the tranny has been pulled close to 5-6 times since I've owned it to find this problem. It's completely rebuilt with 2 different torque converters (my first replace actually had a problem, but fixed under warranty), and the value body was changed twice. The tranny was completely rebuilt about 7000 miles ago. The tranny shop ran some tests, so unless its wiring from the transmission to the computers, the transmission isn't the problem. Also sucks about the possible mouse. I've had a nest right under my manifold next to the fuel injectors. What ever it was, glad it didn't chew any fuel injector wires. I am surprised though a mouse was up in there, seeing as the cluster is completely in the cab and should be sealed. However, I wish you luck on your vehicle as well, and hopefully not anywhere close to what I've had to go through.

 

The PSOM was a dud, and it didn't help anything. Clunk remains the same as before. Looks like I'm on to wiring (harnesses to start). Probably take the transmission harness off the truck and inspect it, and possibly replace it if I see anything wrong. Otherwise, I have 0 ideas for the problem now.

 

I would hook a volt meter up to the EPC solenoid ground wire, and watch the voltage on that line while driving.

 

We just replaced the primary grounding wire that holds the battery clamp and goes to the engine. It was severely corroded. My dad opened it up with a knife, and every single wire strand was green. I'll be taking the transmission wiring off tomorrow. As a question, I believe pin 11 on the transmission was the EPC circuit, and pin 12 was the supply. How exactly would I get a volt meter on the wiring if its underneath the truck, and drive it at the same time? I don't have a volt meter with cables longer than about 2 feet, and the only place I can think of remotely getting a volt meter on is where the wiring goes into the cab from the firewall, and even that is a bit of a stretch.

 

You'll need to tap into the wires, and run some wires up into the cab.

 

Well see what we can do about testing the wires, but for now I will lay off until I get a new connector on my harness. The harness seemed to have the protective rubber pulling off and so a small bit of the wiring going into the connector (which then connects to the transmission solenoid pack) was showing. The wires did not appear to be shorting across each other at all, but I'm still planning to get a new connector put on. As for codes, the only code I keep getting is 225, knock sensor fault during koer dynamic response test, which is now showing up on almost all tests I run, rather than every other test. From what I've read, it can probably be ignored but only has to do with the engine, not the transmission.

I also tested with the TPS disconnected and I got an ABS light (expected), no CEL from that, but the shift pattern changed again similarly to having the VSS unplugged (VSS unplugged gives no ABS/CEL). 1-2 was very mild but up-shifts started to go hard, and downshifts were alright. Well see what happens if I put a new connector but I doubt it will change anything.

 

Changed the connector, but have not tested voltages. New symptom is that from a dead stop, WOT will produce almost perfect shifts, and sometimes very light throttle will produce a decent one (sometimes). Starting at 5-15 mph in 1st gear and stepping on the gas will produce a hard to vigorous shift. From a dead stop under moderate acceleration, or how you'd normally get yourself going from a stop light, the truck will go in hard. I'll look into ways to test the voltage, but without cutting wires, I don't think it's easily achieved with the equipment I have.

 

I use sewing needles to pierce the wire, just make sure they don't short out to each other or other things. Use gator clips on the needles to the test equipment.

Wrap electrical tape over the pinhole to seal it(I never did though,never had issues either) when done testing.

 

What RPM is it shifting at when the hard shifts occur? Is it shifting at the appropriate RPM, just really hard? Or is it winding way out, and then shifting very hard?

 

We tried the sewing needle idea but it didn't work out, so we just cut the line and ran some wires to the cab. The hard shift occurs at almost any rpm, from a light clunk closer to 1500 to very hard at around 2000 to vicious a ways above that. The shift generally occurs around 2000 rpm if your giving it a fair amount of gas, and not being too light on it. The shift is immediate, so I don't believe its "winding way out".

Voltages are listed below for testing the EPC Circuit.

4.00 volts in park/sitting still.
3.78 volts in reverse
2.86-2.90 volts from 1st-2nd shift (under normal acceleration)
2.86-2.90 volts from 2nd to 3rd shift (under normal acceleration)
1.90-2.00 volts when I revved the engine to almost 4500 1st to 2nd (shift felt like a rear end).

 

These solenoids are really based on current, and measuring them with a volt meter can be difficult. Since you cut into the wires anyways, I'd switch it to current mode (amps range) and watch the current.

More current = lower line pressure.

 

Gonna test the circuit again tomorrow (Saturday). Ill check what the current does when it shifts and after, and I'll check the resistance to make sure the solenoid is in good shape. I looked back at your previous post where you mentioned "does the needle on the PSOM shake a bit", and I have started to notice that it does shake around a bit, but not a lot. I would just assume the shaking is from bumps in the road, etc.

I also forgot to mention through most of these posts, but my engagement into drive and sometimes into reverse is still harsh. Drive will always engage harsh (except when its cold out, and after about a minute of driving, will start to go in hard again), and reverse will get a bit bad once the transmission warms up to a decent temp (not full operating). The reverse shift is not harsh from park to reverse (or neutral), but is harsh from drive to reverse, and the worst drive engagement is from reverse to drive. The engagement (in drive) is hard enough to throw you forward in your seat a little.

The tranny lately has also shown a strange symptom but when I am going down the highway at about 60 mph, and I let off the gas to coast (completely off), the tranny will sometimes give a clunk, as though some type of shift occurred. If I reapply the gas, it feels like the tranny shifts again and gives a clunk. No actual shift in gears took place from what I can tell (I don't believe this is normal). Still no codes to go off of.

Lastly, I can still hear a gurgle sound from my transmission around 600 rpm. Only gurgles at around 600-800 rpm (any increase in rpm takes it away) but the sound is centered around the torque converter/pump area. Not sure if this is a cause for concern, but its loud enough to be heard outside the truck (close by) and in the cab while waiting at a light.

 

The gurgling might be from high line pressure