Solved 5R55W problem - P0741 TCC.

[MotoDan]

Hello all. I've got an '02 XLT with 170k miles and have the dreaded P0741 TCC code. I've done a fair amount of homework - much of which was done here on this awesome forum. Also talked to a local tranny shop who, not surprisingly, wanted to sell me on the idea of rebuilding mine. Not being a stranger to getting greasy, I decided to pull the pan, have a look at the oil/magnet, and check the solenoid pack. I was unpleasantly surprised to see dark fluid and metal sludge on the magnet. My biggest concern is the metal chips that came out of the inside of the filter when I cleaned it out. The chips are very small (approx 1/16" or so), non-magnetic, and appear to be brass or bronze.

The solenoid pack checked out fine. I activated all of the solenoids and checked to make sure the related ports were opening/closing. I feel fairly confident that the pack is OK.

I went ahead an pulled the VB which I have only cleaned, but not yet disassembled anything. From what I read, a common problem related to the TCC code is the Lockup Valve. I'm thinking about putting in the Transgo kit - at least the VB portion. Before doing so, does anyone have any thoughts on the metal slude on the magnet as well as the bronze chips? I'm hoping I can get by with the VB mod and possibly replacing the TC. I don't want to do either if these are signs of more serious internal problems.

Any help would be very much appreciated.

 

[MotoDan]

I decided to put the tranny back together after giving everything a good cleaning. The original filter was in good shape - just needed a good flushing. I replaced as much of the old fluid as possible by the add and drain method.

I first temporarily replaced the inner drain plug with a 1/4" NPT hose barb fitting (available at Lowe's, Home Depot, etc). With the engine OFF, I added Mercon V using a hand pump (the kind that looks a bit like a grease gun - about $8.00 from Autozone) connected to the hose barb with a 3 ft piece of clear tubing. I checked to see if the fluid was at the top of the level tube by pulling out on the pump handle after each fill. It took about 8 quarts to bring the dry pan up to the top of fill tube. At this point the engine is ready to be started so that the trans pump can start drawing the new fluid up into the rest of the tranny and TC.

With the engine running in park, I kept adding fluid until it was once again up to the fill level. I shut the engine off after letting the engine idle for about 10 minutes to mix up the old/new fluid. The 4 quarts or so of old fluid was now mixed with the 10+ quarts of fresh fluid. I then removed the clear tubing from the hose barb and let much of the fluid drain back into the tranny pan (about 10-15 minutes).

I reconnected the tubing and pump, started the engine (in Park) and once again began the process of adding fresh fluid up to the fill level. After filling and idling for a few minutes, I drained a sample of fluid out to check the clarity. Mine was clear red at this point so I was done. Replaced the hose barb fitting with the original plug and took her for a test drive.

Now for the best part! Much to my happiness, the first thing I noticed was that the torque converter clutch was again locking up in O/D like it was suppose to. My next grin came from not seeing that pesky flashing O/D light! After driving for about 1/2 hour I decided that all was well again.

Moral to the story... You _may not_ need a transmission overhaul just because you have a flashing O/D light or because your local shop says so. In my case all it took was a good cleaning and fluid flush. Did I completely fix the transmission for good? From what I've read - I doubt it. But at least my wife isn't complaining about "that flashing light on the dash"!

Merry Christmas to All and To All A good Night (in the garage).

 

[BrooklynBay]

Welcome to this forum! Thanks for posting this information. Let us know how it is in a couple of weeks.

 

[bikrboyr6]

Good Write up MotoDan. I know its been a few years since you posted this but its nice to get an idea what I'm looking for. Reading this info makes me more comfortable I can tackle it myself. I also just got the flashing OD light and am told a rebuild is needed. It has been running just fine though so Im not going that route.....yet. Ill probably Flush the fluid, Change the filter, and also probably going to do the upgrade on the VB just for kicks.

 

[MotoDan]

The good news is that it's been 2 years and 50k + miles since I posted this and I'm happy to report that the tranny has worked perfectly and never once thrown up the dreaded flashing O/D!

 

[BrooklynBay]

Thanks for the update!

 

[MotoDan]

P0741 TCC Update

Hello all and Happy New Year!

Well it's been 4 years (almost to the day) and 100k miles since my original post and I'm sorry to say that the dreaded Flashing O/D light is back. I suspect the same P0741 code, but have not verified it. The tranny is going into overdrive, but the torque converter is not locking up as it should. As a result, my gas mileage has dropped from 20 mpg to about 17 mpg. My suspicions are that the valve body needs cleaning again. I have not changed fluid since I first solved this problem which may be the reason for the problem showing back up. A 3 mpg loss is reason enough to once again open up the tranny and see if a good cleaning will fix the problem.

Will report back soon ...

 

[MotoDan]

Update: I repeated the same procedure as previously mentioned where I removed and cleaned the VB (did not disassemble VB) and flushed/replaced fluid with Mercon V. I did this twice hoping to fix the TCC problem. I then replaced the servo pack and reset the PCM by removing battery cable. Still have the flashing O/D and TCC not locking up issue. My next course of action will be to replace the valve body. Hopefully I can get a recommendation on the forum as to where to buy a rebuilt VB. Any other troubleshooting suggestions are welcomed.

 

[BrooklynBay]

Cleaning the valve body on the outside will not remove anything that is stuck inside of a bore. You have to disassemble the valve body to clean each bore. Contact Donny from Central Valve Bodies if you want to buy a remanufactured valve body. Mention this website for a discount.

 

[MotoDan]

I took your advice and purchased a rebuilt valve body from Donny at CVB. The VB arrived in just 2 days. It was very well packed and looked like a new one - complete with a new separator plate as well as several Sonnex mods.

I'm happy to report that the flashing O/D is gone and the torque converter is one again locking up in O/D as it should. I expect to see my normal fuel mileage as a result. With any luck, I'll get another 275k miles!

 

[BrooklynBay]

Thanks for the update! I hope that you mentioned this site to Donny. He helped a lot of members over the years.

 

[DAT05EXPLODER]

I, as well, appreciate you leaving results throughout this thread. They will help people out in the future, so many threads have no results. Thank you.

 

[BrooklynBay]

The title was updated to show that the problem is solved.

 

[MotoDan]

Hey guys,

Thought I'd give you another update on the Explorer. I now have 350k miles on the truck and the tranny is still purring along. The last service that was done to it was when I replaced the valve body back in 2013.

Happy Holidays!
MotoDan

 

[MintyFresh]

Hey guys,

Thought I'd give you another update on the Explorer. I now have 350k miles on the truck and the tranny is still purring along. The last service that was done to it was when I replaced the valve body back in 2013.

Happy Holidays!
MotoDan

Did you ever think to check the Servo?

I'm in a similar situation as you were with the OD light flashing.

 

[MotoDan]

No, I never did anything with the servo. Guess I took a gamble on the valve body which did the trick for me. I did however test the solenoid pack before deciding on the valve body. Let us know what you end up doing to clear the flashing O/D.

 

[MintyFresh]

No, I never did anything with the servo. Guess I took a gamble on the valve body which did the trick for me. Let us know what you end up doing to clear the flashing O/D.

Will do. Good thing is the band isn't broken and the drain pan had normal signs of wear. Error code p0755 says replace solenoid but experts in this forum much more knowledgable than me said its likely the Servo. I let it drain a little over 7 quarts the past couple days and will fill it back up this afternoon.

Stripped the T30 torx plug so I'm going to just find a hose large enough to fit into the entire hole

What an awful design this transmission is. I would love to sit and chat with the engineers

 

[MotoDan]

Not sure what the engineers were thinking regarding the drain/fill plug being one in the same. Guess they were trying to keep DIY'ers from changing their fluid. If I were you, I'd give some thought to either trying to remove the Torx screw or getting a whole new plug. You'll need some way of knowing how much fluid to put in while you're doing it. I found by adding fluid while the engine was running and periodically checking to see if any ran out of the fill tube worked best for me.

 

[imp]

Hey guys,

Thought I'd give you another update on the Explorer. I now have 350k miles on the truck and the tranny is still purring along. The last service that was done to it was when I replaced the valve body back in 2013.

Happy Holidays!
MotoDan

Dan, I'm thinking about selling my '04 while everything still works good. I replaced the solenoid module 2 yrs. ago, no TCC, fixed it. Nothing else done. 150K. Should I keep it?? imp

 

[MintyFresh]

Not sure what the engineers were thinking regarding the drain/fill plug being one in the same. Guess they were trying to keep DIY'ers from changing their fluid. If I were you, I'd give some thought to either trying to remove the Torx screw or getting a whole new plug. You'll need some way of knowing how much fluid to put in while you're doing it. I found by adding fluid while the engine was running and periodically checking to see if any ran out of the fill tube worked best for me.

Yep, I ended up drilling it out and tapping it. Trans definitely shifts smoother but still no 5th gear and has late shifting from 1st to second.

Going to order OD servo, I'll report back results.