99 Automatic Won't Drive Forward

[smithte1994]

Hey, long time reader first time poster.
I blew a coolant hose a month ago, coasted a few hundred feet. Pulled into a gravel lot, turned around using little power and parked it. Had to get it towed. When I got the coolant problem fixed, found that it won't move forward in drive it just revs.
I can kind of feel it go into reverse and it rolls back(I'm on a slight hill). Same goes for neutral, we can push forward in neutral. Can't really feel it go into drive and it just rolls back and revs if I give it some gas. It stalls if I put it in second gear and stalls if I shift around to much. Got under it and the linkage move fine...I guess. On a side note the fuel pump( that's what I guess makes this noise) stays on when I turn key, not start the truck just turn on. It never did that before, it would make slight humming sound then turn off.

Sorry for the long post not good at condensing.

 

[rusty ol ranger]

Sounds like you fried the clutch packs. How did you have it towed? Thats exactly what my expedition did after having it flat towed 3 miles at 25mph.

As for the fuel pump, not sure. Doubt they are related unless its some really bizzare cpu issue.

 

[smithte1994]

Sounds like you fried the clutch packs. How did you have it towed? Thats exactly what my expedition did after having it flat towed 3 miles at 25mph.

As for the fuel pump, not sure. Doubt they are related unless its some really bizzare cpu issue.

Guessing that would call for some serious work. It was towed flat bed, 36 miles various speeds, across state lines from Camden County, NC to Virginia Beach, VA. That's a guess I wasn't actually with him. Its funny you mention the cpu, the top radiator hose going into the thermostat housing blow open in the back just above the housing. It dumped all the coolant in seconds all over the engine, including the PCM which sits a top of the fire wall. I'm getting no codes though.

 

[rusty ol ranger]

If it was for sure flatbedded then i doubt the couple hundred feet of coasting did it in, anythings possible though. Youre kinda in over my head now, hopefully someone a bit more versed in electronics will be along soon.

For now, dont try moving it to lessen any damage to the trans, considering you have a 99 with what i assume to be the 5R55E trans it all could be very well related to the cpu, but im just not sure.

 

[fastpakr]

As far as I know, the computer controls are just for shift points and TCC lockup. With the computer disconnected, the transmission should still function, just with less civilized manners because nothing's being optimized as needed.

 

[rusty ol ranger]

As far as I know, the computer controls are just for shift points and TCC lockup. With the computer disconnected, the transmission should still function, just with less civilized manners because nothing's being optimized as needed.

I was kinda leaning that way, but didnt know if it controlled line pressures or anything.

That being said, pull the trans dipstick and smell the fluid, if its dark brown and smells burnt, then chances are good the trans is toast.

 

[smithte1994]

I was kinda leaning that way, but didnt know if it controlled line pressures or anything.

That being said, pull the trans dipstick and smell the fluid, if its dark brown and smells burnt, then chances are good the trans is toast.

Yeah that's the first thing I checked, still light red with a smidge of black when I wipe on a towel.

 

[rangerenthiusiast]

Sounds like you fried the clutch packs. How did you have it towed? Thats exactly what my expedition did after having it flat towed 3 miles at 25mph.

As for the fuel pump, not sure. Doubt they are related unless its some really bizzare cpu issue.

I’m curious. Why would flat towing in neutral fry the clutch packs?

Sorry to jack your thread, Smith94.

 

[Craig0320]

I’m curious. Why would flat towing in neutral fry the clutch packs?

Wondering the same thing. I have never had it happen towing in neutral. But I never went over 20 miles.

 

[adsm08]

As far as I know, the computer controls are just for shift points and TCC lockup. With the computer disconnected, the transmission should still function, just with less civilized manners because nothing's being optimized as needed.

No, 4/5R44/55E E as in Electronic. That trans is fully dependent on the computer to do anything.

I’m curious. Why would flat towing in neutral fry the clutch packs?

Sorry to jack your thread, Smith94.

Seriously dude. Stop thread jacking. If you have questions go start a new thread. People here are more than willing to answer questions and teach, but you have been around long enough that it is time to start respecting the little bit of etiquette that we actually have around here. We wait until the problem is solved, all the OP's questions are answered, then we jack the thread as far and fast as possible.

Anyway, flat-towing an auto is a big no-no, unless you unhook the drive shaft, or have a manual t-case that you can put in neutral. The rear wheels spinning drives the drive shaft. The drive shaft drives the internals of the trans, which need to be lubricated. In an auto there is nothing in the fluid pool to splash lubricate the internals like in a manual. The fluid has to be pressurized and pumped through the system, like an engine. The pump that does that job in an automatic can only be driven by the engine. So if you flat tow and auto it runs all those bearings and everything dry and cooks all of it.

 

[smithte1994]

As far as I know it’s never been flat towed. The truck wouldn’t start as soon as it was turned off. Come to find out I killed the battery. I’m not exaggerating when I say the ENTIRE engine was drenched. I’m kinda really hoping it is an electrical problem. I have a good chance of fixing that on my own, but a transmission problem is over my head.

 

[rusty ol ranger]

As far as I know it’s never been flat towed. The truck wouldn’t start as soon as it was turned off. Come to find out I killed the battery. I’m not exaggerating when I say the ENTIRE engine was drenched. I’m kinda really hoping it is an electrical problem. I have a good chance of fixing that on my own, but a transmission problem is over my head.

Im going to piss in the dark here but...

Not being familiar with where the cpu is on a 99, and if it is in the location you said it is, the hot ass antifreeze gyser soaked it, and if the antifreeze itself didnt ruin it the heat prolly did.

Coolant will toast a set of crank bearings faster then you can piss, i can only imagine what it would do to ECM internals. That being said, i know you have no codes, but if the ECM completly self destructed that makes sense.

I would price a new computer, and start with that, not really sure what else it could be.

If the fluid is good and red then the trans is more then likely fine.

 

[smithte1994]

Thanks for the help guys, I feel there’s a bit of hope now.

 

[fastpakr]

Which engine do you have?

Sent from my SM-G960U using Tapatalk

 

[rusty ol ranger]

Thanks for the help guys, I feel there’s a bit of hope now.

Theres always hope, it just depends on the effort, time, and money youre willing to invest to realize that hope

Rustys inspirational quote of the day

But in all seriousness, i doubt its anything worth junking the truck over.