2007 Sport Trac 4x4 a really weird acting transmission

[07 Sport Trac 4x4]

2007 explorer sport trac limited 4.6l automatic 4x4 with 198,000 miles. Issue started last summer. Morning start up put it in drive and it acts like the transmission can't decide what gear is wants to be in. Jerking and banging, I stopped and pulled it down into 1st gear and it worked fine manual shifting it. As I have driven it I've noticed that when it's raining it worst. It even acts up trying to manual shift. On mornings with a heavy dew it acts up untill I've driven it for a while then it will quit. When it is nice and dry outside low humidity or its cold 32* or below it doesn't act up at all. So I'm thinking I have a computer getting wet.

I'm trying to figure out a way to explain how it feels, it sort of feels like when you have it switched to 4x4 and your trying to drive on dry pavement and your trying to turn. But this happens driving in a straight line.

I pulled codes, there were no engine codes at all. But I did have 4 or 5 body codes. Can't remember them all so I'll hook my scanner up and pull them again. But one was failure to communicate with transmission computer.

Have any of you had this problem or have you heard of it.

Thanks,
Delos

 

[JK080]

Make sure the fluid level for the transmission is correct. low fluid will give you issues when cold.

 

[boominXplorer]

Check the plug on the transmission for corrosion, the ac drain drips on the transmission.

 

[07 Sport Trac 4x4]

Make sure the fluid level for the transmission is correct. low fluid will give you issues when cold.

Yes I check the fluid level when this problem started. It was about 1/2 quart low but that didn't fix the problem..

Check the plug on the transmission for corrosion, the ac drain drips on the transmission.

There was no corrosion.

This problem seem electrical. I was going to pull codes again but I forgot I had let my son borrow my scanner. When it's a nice day with low humidity (no dew) it shifts fine. But if we have a heavy dew which in Arkansas is very common, It will act up. If it rains it's almost impossible to drive. You can drive it but you have to manual shift it and you can not use drive. I also have a leak some where around the roof area thought it might be the sunroof drains stopped up, but I checked that and they were clear. So it must be leaking around the roof rails or the third brake light. I thought maybe it was running down the A pillars and getting a connector wet. I pulled the kick panel and had no signs of moisture on the passenger side haven't check the driver side yet. But it really does seem to be connected with a moisture problem, water shorting out something. Cause like I said when it's dry or even if the temps fall below freezing the tranny doesn't act up. Also the other day I ran it though a car wash on the way home it acted up and I thought I could smell wiring getting hot, but haven't found it yet.

 

[boominXplorer]

Did you check the round connector on the passenger rear of the transmission? Like unplug and check the pins? Corrosion or fluid contamination in the plug can exactly what your describing.

 

[07 Sport Trac 4x4]

Did you check the round connector on the passenger rear of the transmission? Like unplug and check the pins? Corrosion or fluid contamination in the plug can exactly what your describing.

I have not yet. But thanks I will soon. I'm sort of down for a while, right now I can't lift, pull or push anything over 30lbs. Restictions from my cardiologist till March 18th. Had open heart surgery on Sept 17th and I've got to wait 6 months before I can really do anything. But my son just finished his finals and gets his masters degree this week. He said now that he's done with that he would come over and help me get it up on jack stands. Once we do that I can handle the rest to check out those plugs etc...

Thanks,
Delos

 

[07 Sport Trac 4x4]

Still haven't got to check the connector on the transmission. Trying to get my son to come over, but he's busy, so maybe some day soon.
But I did get to pull codes on the sport trac. I'll tell you this up till yesterday we have fairly dry weather and frost in the mornings instead of dew. So the last two weeks
the transmission has not acted up a single time. Yesterday and today we had a heavy dew and humidity is up and it started acting up again.
The codes are as follows:
4x4 control module U1900-2F CAN Communication Bus Error - Reception Error
ABS U1900 - 20 CAN Communication Bus Error - Reception Error
P0429 - FF Catalyst System Efficiency Under Threshold Bank 1
(I've had this code for a while, someone before I bought the sport trac put dual exhaust
Y pipe back. The used regular steel pipe, not even aluminized. It's got more holes in it
than swiss cheese. Bought a new Gibson single exhaust just with the heart surgery and
everthing haven't got it done either. Also at time I think I can hear a exhaust leak on the
exhaust manifold passenger side.)

U0101 - FF MIssing Communication With The Transmission Control Module (TCM)
Restraint Control Module B1318 - AO Low Battery Voltage.

It must be just the RCM not getting correct voltage, cause I have correct voltage at the battery
and alternator.

Hopefully my son can get over soon and get up on stands for me. Sure will be glad when they
remove this weight restriction off of me.

I was going to get some pictures up of our Explorers, actually thought I had some but I must
have lost them when I switched phones. Right now they are both dirty and I'll wait till we can get
them cleaned up. I can lift a wash mitt! LOL

Thanks,
Delos

 

[boominXplorer]

I'd start simple. Clean all the grounds to make sure your not having a voltage drop issue. Also do you have anything plugged into your obd2 port when the issue happens?

 

[07 Sport Trac 4x4]

I'd start simple. Clean all the grounds to make sure your not having a voltage drop issue. Also do you have anything plugged into your obd2 port when the issue happens?

Yes, I have done that, well I have under the hood area. Also replaced the positive and negative from the battery. I stripped some of the insulation off the negative cable and it was badly corroded. but did not help. I'm sure there are grounds on the chassis that I haven't got to yet.

Delos

 

[C420sailor]

Pull all the connectors on the trans you can reach, clean with contact cleaner, apply dielectric grease, reconnect firmly. It’s good maintenance regardless.

 

[07 Sport Trac 4x4]

Pull all the connectors on the trans you can reach, clean with contact cleaner, apply dielectric grease, reconnect firmly. It’s good maintenance regardless.

That's on my things to do, if my son ever gets time to come over and help me get it up on jack stands.

 

[07 Sport Trac 4x4]

Finally got my wife to operate the jack for me and got the sport trac up on jackstands. I disconnected the plug on the passenger side of the transmission, the plug on the transfer case and there were two plugs mounted on the frame rail so I cleaned and reconnected all of them. Didn't really find any corrosion on any of the plugs, they were a little dusty inside but that's it. However I did notice the twist lock on the right side of the transmission was not turned all the way to lock. It lacked about a 1/4" being turned far enough. I don't know if the plug backed off by itself, or if the shop disconnected it for some reason when I had the transmission serviced at 150K. I drove it this morning without a single hiccup! But it been nice all weekend, so I won't really know till we get our next rain. That's when it acted up the most, when there is a lot of moisture in the air and we didn't even have any dew this morning.

I did find another problem while I was doing this, Ford's bracket as they call it, I'd call it a carrier bearing. It's completely wore out. I'm really surprised that I haven't been feeling a driveline vibration. But most of my driving is 55 and under back and forth to work. So I'm off to search the forum for more info on this.

Thanks for your help.
I'll let you know what happens after we get a rain, we have an 80% chance Tuesday so maybe I won't have to wait too long.

 

[boominXplorer]

Sounds like this may be a cheap fix, fingers crossed.

On the driveshaft some have replaced with oe parts, some swap to the conversion shaft with conventional u joints and carrier bearing($800)

 

[07 Sport Trac 4x4]

Sounds like this may be a cheap fix, fingers crossed.

On the driveshaft some have replaced with oe parts, some swap to the conversion shaft with conventional u joints and carrier bearing($800)

I'm sure hoping thats all it was, but I'll know more when it starts raining again, cause that's when it really acted up.

I ordered a new driveshaft from Tulsa Driveshaft Inc. It has a replaceable u-joints and center bearing. $575 which includes shipping.

Thanks,