1999 Ford Explorer O/D light flashes

[bhmayor]

Ford experts,

I was driving my 175K mile 1999 Ford Explorer on the highway, well over 50 MPH and the O/D light started to flash (I had not pressed the O/D button on the end of the shifter). I pulled over, shut off the engine for 5 minutes, restarted the truck and drove on the street for a little while (wherein the O/D light remained off). Then, whence I returned to the highway and got it up over 45-50MPH the O/D light came back on again.

The car goes into reverse just fine (if that matters) and seems to drive fine on the street locally, only when I drive on the highway for more than a few miles does this issue instantiate itself.

The MIL/check engine light is off and I own a CENTECH code reader and didn't see any stored or pending codes on the truck (I'd have to check, but I think the CENTECH is Harbor Freight model 60694). It seems the code reader (from the online manual) can read transmission codes (though I am not entirely sure).

Can anyone give me any idea of what it might be?

I tried to do some research myself (I am NOT a mechanic, nor do I play one on TV) and read about bad 3rd gears, TCC solenoid valves, valve cover gaskets, etc... but there seem to be the same descriptions and a multitude of solutions (with no specific way described to work in pursuance of ascertaining which solution might be most applicable to my situation).

I recently replaced a fuel pump on the truck (with a friend's help) and just want to know if it is something I might be able to repair myself or if I need a new transmission or what. I am willing to attempt repairs that are not too difficult.

Also, how can I determine if I have this 5R??? transmission or not or which 5R??? one I have exactly?

Thanks in advance!

 

[Robman]

Torque converter isn't locking up.

Locks 1:1 at highway speeds and it appears that yours isn't and that's bad news.

v6 motor? 5r55e.

It could just be the tcc solenoid if yer lucky.

 

[bhmayor]

Torque converter isn't locking up.

Locks 1:1 at highway speeds and it appears that yours isn't and that's bad news.

v6 motor? 5r55e.

It could just be the tcc solenoid if yer lucky.

Robman,

I believe I have an 4.0L V6 SOHC, thus I presume this means the 5R55E transmission.

I didn't really understand your sentence about Locks 1:1, etc...but I am willing to learn if you feel impelled to provide a deeper explanation.

I suppose I ought to take it to a transmission shop that will give me a free estimate (if there is such a thing) and find out if it is just the TCC Solenoid or not. If it is the TCC Solenoid, is that something that is easily and/or inexpensively replaced?

A friend also told me that truck was likely going into "Safe Mode" (I am a Computer Scientist) and said I only know that mode for Windows! He laughed and said you need to know the truck is likely doing that.

Thanks in advance!

 

[Robman]

It's been awhile since I dealt with this problem but I'll give it a shot explaining it off the cuff...

At highway speeds, the torque converter goes in lock-step with the motor in a 1:1 ratio, I'm guessing that if it were to fail to unlock, when you slowed down the engine would stall out.

There's a solenoid on the valve body in the transmission that controls this. Drop the transmission oil pan to get to it. Don't let any transmission guys tell you your exhaust is in the way for this job. If they refuse, go somewhere else.. could even tackle this yourself with some know how. I suppose the first thing to do would be to get the codes read to confirm the issue.

Safe mode for the transmission changes shift points and I don't think it even allows you to get into the taller gears or even overdrive. When it's in this mode, you'll eat fuel. In some ways it's similar to windows safe mode where it runs on just the basics.

The SOHC/5r55e combination is the most unreliable to have in the explorers but it's pretty much the most common. They are nice when they are working properly though.

I think pre 1995 they used a transmission similar to the 5r55e which is a 5 speed automatic but the previous version only had 4 gears.

To my knowledge it goes like this:

You can get 3 motors in the 2nd generation explorers:
v6 4.0L OHV 160-170hp (pushrod motor) 1995-2000 (5r55e(auto) or m5od(standard) transmissions.

v6 4.0L SOHC 205hp single overhead cam motor. 1996(or7)-2003 (5r55e(auto) or hdm5od(standard) trans.

v8 5.0L OHV 235hp?(pushrod) A4od? ( the v8 takes a different auto tranny than the v6s, I can't exactly remember what it's called. No standard trans for the v8 )

In stock form, the SOHC v6 is actually quicker off the line than the v8.

Anybody feel free to correct anything I said.

 

[Mike65]

A great big thanks to Robman for posting about how to remove the trans pan w/the SOHC motor w/the cat converter under the trans pan. Doing a google search on how to replace the TCC solenoid I came across a thread from 6/15/2013 where he stated to remove the front drive shaft at the front dif & swing it out of the way then you could remove the pan. Well I did it yesterday & it worked GREAT. I removed the pan, replace the filter & the TCC solenoid. I road tested it today & it seems to be going into OD when I road tested it today. Also I was told the exhaust had to come down to get the trans pan off by an independent repair shop so I googled the problem & got the answer from here & did the work myself. Thanks again for the info & a GREAT site.

 

[RadioDoc]

Several times over the past week, my 1996 two-wheel drive started flashing the "O/D OFF" light, but rpms seemed to be correct for converter lock-up.

1500 rpm at around 60.... not above 2000 like when OD is OFF.

When this happens, the ON/OFF pushbutton has no effect, but I can reset it at a traffic stop by turning off the ignition key and back on again
( less than 5 seconds ).

The transmission was rebuilt last year ( $1700 ) and has under 50K miles
( speedometer works but not the odometer ..... another issue ).

Probably out of the warrantee period ..... ( sigh )

 

[Robman]

I just noticed this...

I'm thrilled that my ramblings have helped somebody!