Sorry for the long post! Just wanted to cover everything I️ could think of to help explain my situation! It is a 1994 7.3 IDIT XLT

So I️ have recently just started driving my new truck. When I️ bought it the transmission was destroyed and sitting in the box. I️ picked up one from guy a couple hours away who has a bone yard of old

I’m experiencing problems I️ had in my other truck that the transmission went in about a month and a half ago, I️ thought I️ was in four low but was in four high when I️ tried towing my dad out, my mistake. It is shifting very weird. When it kicks down from third to second, I️ believe, it only seems to half shift, and then it goes into gear. I’m not having any issues when it shifts up into any gear. Another issue I️ am having is it randomly kicking down when just cruising at about 80kmh or about 110kmh. It kicks down and revs crazy high and doesn’t want to shift back up, I️ have to baby it for about a km and then it seems to level out. I’ve had it on the road for two days now and it has done it twice today and once yesterday, and one other day when test driving it. The first time it happened I️ thought it was due to low fluid because it was low, we filled it up and went out again and never had any problems, but it has done it again and the fluid level is fine. It also has a delay when shifting into drive or reverse, when you shift into gear it doesn’t do the little jump right away, it does it about 4 seconds after shifting into it.

There is four things the truck has other problems with that could be linked to this from some reading I️ did earlier.... My third brake light doesn’t work, I️ believe the front seal is bad on the transmission due to some transmission fluid coming out of the inspection plate, I️ also have no reverse lights and my speedo bounces very vigorously when I️ go past 100kmh

So my question is where to start? Do I️ start by replacing the neutral safety switch, or the speed sensor? Or do I️ look into wiring for the lights? Or is there something small that I’m missing.

Any help is appreciated!

I️ know that my reverse lights aren’t burnt out because I️ just put new ones in, and here is no power to the reverse lights on my trailer plug. I️m not sure if the third break light is burnt out though.

I️ know that the transmission wiring runs with the third break light and a burnt bulb can cause problems, but I’m not sure the problems it caused. I️ know that a bad speed sensor can cause problems with shifting and I️ read that it can cause the speedo to jump too. But I’m not sure if having no brake lights is tied into my problems or if it’s just a poor connection somewhere or a broken wire.

I️ apologize for all the messed up I️ things, my phones acting up but I’m pretty sure lots of peoples are. If this doesn’t show up as a problem for you, this will make no sense lol.

 

Yeah,your phone is messed up alright lol.So it sounds like your TPS might be wore out,the PSOM might be bad and your solenoid pack plug could use an inspection.

First things first.Go ahead and replace the FIPL/TPS.That's a ware item and should be changed every 50k miles.Hard to say how many miles are on it.
Go here:
A/T - E40D FIPL (TPS) Sensor Trouble Shooting & Adjustment (Diesel Applications Only)

Inspect & clean your bulkhead connector.
Go here:
E40D: The Importance Of A Clean Trans Harness.

Also replace your 3rd brake light.

On top of your rear diff is the VSS/ABS sensor.Pull it out,wipe it off and put it back in.It may or may not clear all that ails the speedo but it's free and worth a shot.


Those are must do's no matter what.Next is;do you have a flashing OD light? (to ensure the light works,press the button to cancel OD)

Side info you should know for some of your concerns;
A delay into reverse is common with these trans.Nothing to worry about.
A semi shift is the converter locking and or unlocking.
You'll have to pull the trans to replace the front seal.Save this for last,so long as it's not losing large amounts of fluid.You want to see if the trans is ok before pulling it for a seal.

 

Okay, so I had to do some googling to find out what those abbreviations meant because I wasn’t sure. So I know my trans harness is clean because we made sure it was before we put everything back together. As far as the psom and tsp I am going to save that for last as I don’t have much money right now. Hoping to only have to replace the vss and the third brake light. My od is not flashing, and it does work.

And okay I wasn’t sure if the delay was tied into everything or not. And yes I know I have to pull the trans to do the front seal, we already have had it out once since the first time we put it in (bad frost plug that we didn’t know about).

Thanks for the help!

 

I learn something new every time I read one of the threads. Keep up the good work!

 

Yeah,what happens there is,some ware in the rear causes very small metal particles to accumulate on the sensor and over a long time causes the signal to become disrupted.

 

Thanks, if it ever stops raining I will clean mine.

 

Okay, so a little update. My third brake light does work, so not the problem. I knew either my dome lights didn’t work or the actual brake light and I got it backwards, brake light works, dome lights don’t. I bought a new speed sensor to put in tomorrow, hopefully that will solve my problem. But on another note my transmission oil went from good to smelling very burnt in a day. Last night it was fine and when I checked it today it was very burnt smelling. I know it’s not slipping so I’m not sure what else could have caused that. I have a slightly smaller than stock cooler but just driving with no load should not of made the transmission get that hot that it cooked the transmission oil, considering I only drove for a max of 45 minutes straight and it would have cooled down almost completely between drives.