5r55w - p0741 after shift kit and high stall converter.

[zerodevil]

Alrighty lads, i have been posting a little about this on the 3rd gen modified section with no leads to speak of, so i am bringing it on over here. About a month ago my 5r55w finaly failed on me (no 2nd or 5th, was accurately diagnosed as OD servo bore ware). I Had the Transmission rebuild AS NEW, along with a TCI hardened input shaft, TCI Jumbo OD, and intermediate servo, a superior-transmission shift correction package, and a performance automatic deep dish pan with a custom extended pick up tube. I also bolted a brand new TCI 2500 stall brakeaway torque converter to her, with lock up. Long story short the truck seems to run and drive great, but if i am cruising at any speed over 45 mph for more than 3ish minutes i get trouble coude p0741 " torque converter clutch stuck off". I imediately had the truck returned to the shop where i was told after a live feed data-moniter that the truck was just detecting to much slip from the torque converter, and that the transmission is doing everything it is supposed to. I asked my tuner about this and he claims that in many mustangs this code has never reared its butt ugly head. I believe the transmission shop has a conflict of interest given they may be the ones that messed somthing up (shift kit is where my money is at). Well, last thursday the truck blew the front cooler line off of the ATF cooler, i again had the truck returned to the shop (not 24 hours after they gave it a clean bill of health). They pulled the pan and did an inspection of the trans, thankfully nothing was fried, and they also refilled the transmission with 10 Qt's of royal purple for me, all free of charge(blamed the blow out on an old clamp, ruber lines rather than hard lines, and 3x fluid to the cooler from the shift kit mods)(also advised me to upgraded to braided steel lines and AN fittings). This time i had them hop into the truck with me and let me drive them around while they did an active data moniter on the truck, and confirmed for me that the TCC is indeed engaging when it should be, and that the code p0741 is spawning from the PCM detecting to much slipage in the TC when the TCC is engaged. has anyone else had this sort of problem from the 5r55w after the superior shift kit was installed? i have no way of knowing or comparing the kit with out having to purchase another kit and then to rip the valve body out to look at it.. Again the truck shifts smooth as silk and runs a full 25 degrees cooler than before, but i get that crazed light after i hold high rates of speed in OD. advice? shift kit or torque converter? or tune?

 

[zerodevil]

bump
i also returned the truck to the stock PCM tune last night, same problem.

 

[PopRichie77]

A shift kit does not give smooth as silk shifts, it's purpose is to give quick firm shifts, every shift can be felt, the quicker, firmer shifts are to prevent clutch and band wear. Also it should not cause a P0741 code. You can call Superior and talk to a tech. The torque converter could be at fault but doubtful. Was the solenoid pack replaced? Leakage some where or low pump pressure is more likely the cause. It would appear that there isn't adequate pressure reaching the torque converter to keep it locked. By just dropping the pan, you can't tell if anything is fried, about all you can see is the valve body.

 

[zerodevil]

I spent 25 minutes on the phone with Bob White yesterday, who was the lead engineer of this kit. The kit is designed to provide very rapid shifts, but there is no harsh luck up because of the alterations the kit makes to the valve body. at WOT you can feel it go into the next gear, but under normal driving conditions if you could not hear the engine you woudlnt know it had changed gear. The Kit also makes some alterations to the lubrication system, including the pump, and it nearly tripples flow to the cooler.
I had a brand new solenoid pack installed in the trans with this full rebuild..
The truck now has 250 miles on it since the rebuild and seems to be working as it should, I am getting a little more noise from the bellhousing than i am used to as well, when the TC is cold it gets a slight whine to it, but that disipates when the vehicle is warm.. there is a constant "hum" at any conditon though. My transmission shop thought nothing of this.

 

[zerodevil]

a thought. I did switch to a heavy duty flexplate for a six bolt 5r55s, and i did not measure the deck hight of it, nor did i measure the TC to engine block distance (hindsight is 20/20!!). If the torque converter was to far forward on the pump gear, the solenoid would not be able to push the input shaft forward and engage the TC clutch properly, I am going to measure this tonight and i will let you know. this would also account for the bell housing noise. If the distances are to great i intend to shim the TQ with high quality steel machined washers..which i will measure with my micrometer.

 

[PopRichie77]

The input shaft engages about 3/4 of an inch, also if the TC was to far forward it would not engage the pump gear but if it was forward just enough to be past the pump gear o-ring which is a seal for torque converter lockup, this would cause poor lockup. It could cause pump gear noise also. Will take a look at the manual to make sure what I said is correct.

 

[PopRichie77]

There is no solenoid that pushes the input shaft, it is engaged all the time, the TC clutch is applied hydraulically, one of the seals is the o-ring in the pump gear that is driven by the TC hub, about a 1/4 of an inch to far forward would be out of the o-ring. Hydraulic pressure would dislodge the o-ring completely. Also if you installed the TC into the pump and the o-ring was not tight in the pump gear it could have been dislodged. None of this might be the problem but could be.

 

[zerodevil]

would the transmission still operate with a dislodged o-ring? I have purchased precision washers and measured them to be accurately sized to with in 1/10,000 inch, and should be able to shim the TC in the truck. If this does not fix my issue the trans will be coming back out of the truck to be re-examined by my transmission shop.. I did the mechanical check for lock up (high engine rpm in OD, for me this was 70 mph in 4th gear (aprox 3500 rpm), i applied the brake while maintaining speed and no rise in engine RPM was detected, NO lock up present. But i have seen through live data loging that the TCC is engaging when it should. means the torque converter is to blame. I am hoping i have caught this in time and no seals or o rings have be dislodged and by propper shimming my issue will go away. I will update tomorrow afternoon on what i have been able to find out!.

p.s. the torque converter is sitting about 1/4 to 3/8ths from the flex plate when fully seated on the transmission, WAY to far. learning curb mistake, that i dont intend to make again.

 

[PopRichie77]

That O-ring seal in the pump gear to converter hub is only for torque converter lockup also there is a seal on the end of the pump that is a lock up seal. Both can be bad and the trans will shift fine, just no torque converter lockup.
If you don't have an ATSG trans manual you should get one.

 

[Ronin8002]

Zerodevil it just so happens I have an ATSG 5r55s/w manual that I am looking to sell (not in my for sale thread yet). PM me if you are interested.

 

[zerodevil]

PM sent!

So is it a gaurantee that the seals are blown? or is it just one of those things that will eventually happen if left unchecked? The truck hasnt been driven hard at all, minus one 0-60. I will try and shim in either case just on the off chance that everything is still solid. I will keep you updated.

 

[PopRichie77]

No, it's not a guarantee but something is leaking before or in the Torque converter apply circuit so that there isn't enough pressure to lock it up. I don't know what the difference is in the flex plates but the fact that you used the wrong one, makes this area suspect. There are many other things that can cause this problem.

 

[zerodevil]

Agreed.. It could be anything from a leaking gasket inside, to a ruined TC, to a bad solenoid pack. I think i will be turning this over to the experts again (my pocket book is getting tired of that), I have a feeling this is beyond my current level of expertise. Im going to attempt to shim this weekend and see what happens. If that fails me she will deffinately be going back to the Shop.

 

[PopRichie77]

If the Torque Converter will move rearward far enough so that the studs are out of the flex plate, there is definitely something wrong there. Also if it moves that far the TC pilot may become disengaged.

 

[Sedition]

Tranny Hum

There is a constant "hum" at any conditon though. My transmission shop thought nothing of this.

Just to let you know...... My 5R55e hums quite loudly when it is very warm. Once it has cooled off the hum goes away. It's just the ATF cooler running at full flow. I get this when running on sand. My box is standard with no problems. Yet.

 

[zerodevil]

This torque converter has billet front plate and does not have studs, it uses bolts fed through the front of the flex plate. I pushed it all the way back to seated with no difficulties using longer bolts. I have 3/8ths plus between the tc and flexplate. I'm going to attempt to shim through the starter hole with some string and a strong magnet.. WAY to much room. I'll update tomorrow when all is said and done.

 

[PopRichie77]

Keep it about an 1/8 from being fully in the pump, there has to be some clearance for flex and it should not put pressure on the gear or the pump bottom.

 

[zerodevil]

Long story short, Was unable to get shims in place. There just simply isnt enough room in the starter hole to get a washer in place and then to feed a bolt through it. My solution? im going to cover all of the bases. The transmission is coming out of the truck this weekend again -sigh-. I will be taking precision measurements, getting the propper washers fabricated (or purchased if they are available), and then installing grade 8 double ended studs onto the torque converter (with libral use of thread-locker). This will allow me to install the shim washers prior to installation
while this is going on i am going to have the trans shop dismantle the transmission to ensure it is propperly assembled and to replace any dislodged or damaged seals. Bob White with superior transmission has offered to talk the shop tech through the install of his kit step by step, and i intend to take him up on it. If needed i will get a high quality reman valve body and have the kit installed on that. Is there is way to test the torque converter to see if it is still AOK? TCI has offered to take it back and have it tested for free (minus the $150 in shipping its going to cost me), but i would rather have it done localy if at all possible. I will keep you all updated! thanks again for all of the sugjestions. But it looks like i need to bite the bullet on what is probably my mistake.

 

[PopRichie77]

I feel your pain but it is the right way to go. The shop probably will do this but ask them to check the center support bearing area for cracks also the seals, as leakage in this area could cause your problem also. Best of luck on finding the problem.

 

[zerodevil]

finally got motivated this last weekend to get the transmission out of the truck again, from start to finnish it was about 5 hours... im getting way to good at this hahaha. The trans is getting accepted by the trans shop tomorrow morning and the TCI converter is going out on an RMA tonight. My reason for the post here is that both the seal around the neck of the pump shaft, and the seal at the end of the pump shaft are still in place and look in excellent shape. Which kind of shoots down my theory, I am going to try and talk the transhop into pulling the valve body to ensure propper assembly of the lock up system. This should cover all of my bases.