I have a 1997 F250 with the 7.3 Power-stroke, 4x4, XCAB long bed. Bought it a week ago and have just been doing cleaning too it and haven’t really drove it. The kid i bought it from put a new torque converter installed it. On the first drive in it a week after i bought it i realized that it did not want to go into 4th gear. It didn’t once, though. it felt like it was slipping and crap like that the entire drive. Also in reverse you would dang near have to have it at the limiter before it would start to move back wards. I also know that third brake light controls how the torque converter locks up and how it acts and for some reason my third break light has a running light mode? (like when you turn the headlights on, the third brake light comes on dimmer, but gets brighter when you hit the breaks, just like a normal taillight.) And the speedometer also jumps around while driving. which i’ve heard this can tell the transmission when to shift and stuff like that. On the drive home from the first drive we couldn’t get it in 3rd gear any more. once we got home we realized we blew the front pump seal and leaked atf out for a 4 mile distance😭 Does anyone have any idea what’s going on? Is this hopefully just a combination of stuff causing the transmission to act weird or do i just need a whole new one? Has 220k on it.

 

The first step is to read the codes. Without codes, all anyone can do is guess.

Your statement that "in reverse you would dang near have to have it at the limiter before it would start to move back wards." tells me that you probably wiped out a clutch or two. Since you now say it doesn't want to go into third gear, you've probably destroyed the direct clutch with that one reverse engagement.

 

I'm 1000% sure Mark has forgotten more about these than I know, and I'm not contradicting him, but I'll add a few things from my experiences.

First, although checking codes is good procedure, there are no codes to pull if your car is like mine. I have the OBDI and I've checked the codes, there has never been anything related to the transmission no matter how much it clunks and how wild the speedo gets. Who knows why? I've heard some of these have the OBDII and maybe that makes a difference.

On my 96 with 230k on the E40D, I also have a wild speedo and rough shifting. I found that replacing the VSS in the rear diff (with a quality NAPA part) improved both, but did not fix either. (I also remember in my research that sometimes the VSS is in the transmission itself, or maybe there are even two in some cases. Mine was in the rear diff and - I think - only in the rear diff.) Be careful with the wires in the harness, they are fragile. Maybe buy a new plug/connector for the VSS when you buy the new VSS.

Then I removed the RABS module (behind the glove box. Just unplug it) and that improved both the clunking and the speedo needle a lot - but the speedo was still wild above about 50. This post (from Mark who replied above) just the other day really shed light on that:
https://www.ford-trucks.com/forums/1...l#post21704882

Then I cleaned all of my grounds (after @rla2005 pointed me to this thread: https://www.ford-trucks.com/forums/1...nd-points.html) and reinstalled the RABS module. One test drive suggests the shifting is smooth but the speedo is still wild above 50.

I've found this thread helpful in understanding the wild speedo above 50 problem (which I assume is unrelated to the wild speedo *below* 50 problem, which I am tentatively believing was caused by bad grounds): https://www.ford-trucks.com/forums/1...led-codes.html.

You'll see how Mark's post (that I linked to) says Ford suggests getting a new PSOM to fix the wild speedo over 50 and clunking. But that post I just linked to includes one fella who replaced the capacitors on his PSOM, which I am guessing will have the effect of muffling errant signals as described in the Ford note as the problem solved by installing a new PSOM. So I intend to try that at some point.

Oh, I also greased the driveshaft with a special Ford lubricant (Motorcraft PTFE (XG-8)) and it made a huge difference - that was before the VSS etc. Removing that ds was a pain because of the type of fasteners used and it's a known problem and better replacement fasteners are available. (I may have changed a u-joint or three in the process.)

I have a 3rd brake light and I did not know that this was connected to the speedo circuit, thank you! I didn't think I had a running light mode, but then again maybe that lamp is bad, I'll have to check. But I wonder if yours has been tampered with? For example, if you had a topper or camper where the brake light wiring was messed with to make the topper brake light work? (I think that is supposed to be done from the 7-pin trailer plug, not the light itself, but that doesn't mean it was done that way.)

Anyway, good luck and although I'd bet money he's right, I hope Mark is wrong in this case and your transmission is fine.

 

It does have a OBD2 port and does throw codes, yet they are all three emission related and nothing for the transmission.

Welp i guess how hard is it to rebuild a E40D?

 

I’ll have to look into all these things in the morning. It kinda makes sense on how it would be acting up with the third brake light and the torque converter being weird but at the same time i bet he’s right and the transmission is just cooked. Also my issue with the speedometer occurs as all speeds and not just over 50, so idk if that is still just a bad vss or something else. Just pulled the transmission a few hours ago and found the front pump seal stuck around the torque converter instead of tapped into place on the transmission.😬

 

Hands up. The one PCM in these trucks that controls both engine and trans is programmed to force the transmission into a limp mode of sorts.. high line pressure which causes delayed hard shifting if sensor inputs become erratic or are out of range, so all codes are trans codes to some extent.. Of all the sensors on the powertrain the computer speed input and MLPS(gear shifter position) are critical for correct transmission operation, but engine control issues outside that can also have an impact. The signal chain for the vehicle speed isn't direct it starts at the VSS goes through the RABS module then goes to the PSOM module on the speedo and then goes to the PCM, so there are several places where the signal can get corrupted or lost.

 

The third brake light can affect the torque converter lockup. That's all it can affect.

 

That's the one that went away for me when I pulled the RABS module. Sounds like you're deep in it at this point, but *if* that is the cause for you also, then rebuilding the trans won't solve that particular problem, and it will be easy to test by removing that module. But it's not the module itself, because I've used a few. I also cleaned all the grounds and *maybe* the speedo is only bad above 50 now, even with the RABS installed. (Only test drove once.) That makes sense to me actually, especially since RABS is one of the ground points. I also feel strongly about the PSOM needing replacement or new capacitors to fix the speedo above 50, but haven't done anything with that yet.

Anyway, good luck. Sounds like your problems go much deeper than the speedo and I hope you receive a Christmas miracle.