flashing o,d light

[Sport1998]

Hey guys, Im a new member and Im have some Tranny/ Torque converter problems. Ive got a 1998 Explorer sport 5r55e tranny I believe. My O/D light flash's occasionally. It often resests itself while driving. It happens just about every time I drive the truck but not all the time. My mechanic checked it out and he ruled it to the tranny/ torque converter but couldnt scan it any further than that. Its been going on for about a year. It still hits highway speeds fine but when its on the tranny clunks pretty loud. It has 120k miles on it currently.

Any help is appreciated, after reading this thread it sounds as if it might be the solenoid but we arent sure. If anyone has had this problem befor or has any insite for me let me know.

 

[thecause17]

I'm bringing this post back up. Today on my way to work as I was coasting off an offramp off the highway, my O/D light started flashing. I pulled it into work, shut it off, started it back up and it was still on. So at the end of the day when I left, I started it and it was still blinking. I got back out on the highway and was doing about 50mph or so and it went out. I was pretty happy hoping it was only a glitch but it came back shortly after that. The whole time it doesn't seem to be going into O/D when it's supposed to and the shifting is a little hard, even when coasting to a stop I can feel the downshifts. I reset the computer, started it up and it wasn't blinking. I took it back out and it didn't come back on until I hit about 60mph where the torque coverer should've locked up around that time, but didn't.

I haven't had it scanned yet, but it seems like this is a similar problem. It seems to be going into overdrive, but the torque coverter doesn't seem to be locking up. Seems to be sensor related since it went away when reset. Any ideas?

 

[Russ in CT]

I don't know why the light is coming on (could be the solenoid, either electrical issue magnetically 'holding' the valve in place with sufficient force or a hydraulic leak preventing full force to the TCC to lock it firmly), could be the TCC clutch plates tehmselves (worn TC that needs to be replaced), or something else. However, I can help you with the firm shifts. What is happening is that once the light comes on, the tranny is going into 'high-pressure mode', upping the system pressure to try and compensate for a weakly applied clutch in hopes of preventing it from slipping, and causing further damage.

You will feel the firmer shifts on upshift as well as downshift. They seem to be particualry noticable when coming to a stop, as you drop down through, say, 10 mph. These firmer shifts can feel disconcerting, as though something is REALLY wrong, but all it is the firmer shifts from the higher pressure (of course, something is causign the light to come on (and code that goes with it), and whatever that is could be something REALLY wrong).

If you shut of and restart (to temporarily clear the code), then the shifts seem 'normal' again. This is simply because you aren't in 'high-pressure mode' anymore.

While it may feel like you're 'helping' things by shutting off and restarting to clear the code, and thereby the odd shifts, I argue you're better off letting it stay in 'high-pressure mode', since this could be helping to prevent slipping which would be the death of the friction material in the TCC (or whatever is actually slipping and causing the code).

 

[thecause17]

Actually it doesn't reset just by shutting off, I had actually had to disconnect the battery to do it. I sort of suspected that the hard shifts were sort of a "limp mode" that the ECU was going into, sine it only happened when the light was on.

I got it scanned and I am getting the P0741 code, which coicides withit's behavior. The scanner reads "Torque Converter CKT Performance or Stuck Off"

Where should I go from here? What sort of solenoids and such are there, I am not familiar with this tranny.

 

[thecause17]

http://www.explorerforum.com/forums/showthread.php?t=83021&highlight=P0741

This thread shows promise...I am most likely going to give that a shot.

 

[Russ in CT]

There is a Ford TSB on a lot of 'bad' TCC solenoids for vehicles manufactured prior to some date in '98, can't recall exactley. Just did a search, couldn't find it. But point is TCC is probably a good place to start.

This job is pretty easy, drop the front drive shaft (or the CAT that goes under the pan, which will be a pain), drop the pan, remove the filter, and the TCC solenoid is accessible. There is a bank of 4 solenoids in a row, and its the one on the end (can't recall if its the front corner or rear, there are some decent photos in here if you search). Its held on by a bracket, you'll have to remove a couple of the VB screws to get the bracket off, then the TCC itself has a VB screw holding it on. Don't forget to unplug it from its connector before you remove it.

Carefull on the screws, they are slightly different lengths, get them in the correct holes.

While you have the pan off, mount the drain plug. Use some lock-tite on the threads (not the plug threads, the threads with the nut), and some silicone on the plastic washers on both sides of the pan (let the silicone dry before you pour in fluid.) Use some teflon tape on the threads of the removable plug. You may also want to replace the little o-ring on the plug with something more robust. You can get a flat rubber washer with a metal washer bonded to it at Home-Depot that will fit the plug. Bring the plug with you to match it up.

Pop out the old solenoid once the screws are out, and button it back up, don't forget the new filter, put in 4 quarts, then top it off once its running.

You'll want to get the Solenoid, a filter/gasket kit, and about 5 quarts of fluid (Mercon V, not III), and a drain plug kit while you're at it (and a 1/2 inch bit for drilling the pan if you don't have that size), before you start. Make sure you have lock-tite, teflon tape, silicone, and the flat rubber/metal washer, too. Be prepared to get tranny fluid in your hair.

 

[Glacier991]

That's assuming you have hair!

 

[thecause17]

Why would I need to drill the pan?

 

[thecause17]

I'm looking at several other threads and this is getting confusing, I'm not sure where to start, or how extensive this could get.

Drove it again today. Seems when I first start driving it, the light is on, but will go out, and the torque coverter seems to lock up, but possibly not fully. The light will go out. Drove it for about 5 miles without the light coming on, then it came back on again and was on the rest of the time i drove it. I'm not sure if I should just replace the solenoid, or the whole valve body. Do the rebuilt ones come with all new solenoids? i also read a thread about a possible faulty seal as well,that looks like it could get expensive.

I can't seemto find anywhere local who can get that solenoid but ford themselves, along with the filter too.

 

[410Fortune]

forgive me if you did this already, but did you pull the code?

 

[Russ in CT]

yes, he pulled the code, P0741.

 

[Russ in CT]

Well, it could be the TC (clutches worn). It could be something that is resulting in insufficient pressure to be exerted to the TC clutch (such as a leaking TCC solenoid, a bad TC seal, or other internal 'leak'), or it could be an electrical, or magentic, problem with the TCC solenoid (not engaging fully).

We know a few things, there was a TSB from Ford regarding a bad batch of TCC solenoids that would develop a leak. And the TCC is easy to do yourself if you can wrench, none of the other things are very easy, and require you to drop the tranny.

I'd just do the solenoid and a complete fluid flush (requires 15 quarts or so, there are posts on how to do it, but basically you're disconnecting a tranny cooling line, attaching a clear hose (Home Depot), and adding fluid as it runs out with the engine running - don't let it run low - until it comes out fresh and clear). I read somewhere online that P0741 could also result from contaiminated fluid (I guess that allows the TCC to slip?) This is why I'm suggesting the flush.

If the solenoid and new fluid don't resolve it, you're only out about $100 (you can only get the solenoid from a dealer, but its around $70 buying it from a dealer online.) If its something more than this, tranny has to come out.

Most likely culprit is the solenoid, and its the easiest, plus pretty cheap to do. I say go for it.

 

[thecause17]

I went to Advance and they listed a solenoid for the tranny, but it didn't say what it was for...there were actually two. I called the dealer today, they want $89 for one. I don't think it's a problem with worn clutches, it shifts fine through each gear, no slippage whatsoever, and it only shifts are when in that "limp mode" when the light comes on. I tried an additive today in hopes of unsticking a stuck valve and it did nothing.

 

[thecause17]

http://www.partsamerica.com/ProductList.aspx?PartType=424&PTSet=A&SearchFor=Transmission Solenoid Here are those solenoids they list. Anybody recognize one by the picture?

 

[thecause17]

I was looking into used trannies today, and the data base I'm searching is asking to choose from trannies with or without a "drum sensor" Does anybody know what that is and how I would know if I need one with or without?