Converter slip

[05wh250]

I'm having an ongoing issue with my race truck. I bought a used transmission and converter, trans is supposed to have 500 miles on a rebuild and about 1300 miles on the hard parts. Its continually hitting the rev limiter on the 2-3 shift. After multiple tune revisions last year it started shifting properly. Found a hpo leak this winter and now its hitting the rev limiter again. I datalogged it and sent it to the tuner, its max slip in an 1/8 mile run is 540, this is in a race tune where the converter should be locked. So, is this too much slip? And what should I look at first to try to solve this?


The trans is from RCD and is supposed to have every aftermarket hard part available and the converter is a DPC quad disk w/ a 2200 stall.

The engine has 190/100's and a 68 vgt.

 

[Mark Kovalsky]

If the converter is locked you shouldn't see more than 10-15 RPM slip. 540 RPM is an unlocked converter.

 

[05wh250]

Alright, thanks. Any suggestions on where to start looking? Don't know of much h about the technical side of these transmissions.

 

[05wh250]

Just to update, checked the harness last night and didn't find any rubs, checked the ground wire for the torque converter solenoid and it was fine. Got the pan off today and ohmed the solenoid and it checked fine. Checked the internal harness for continuity on both wires for the solenoid and they were fine. Is there a way to check that the pcm is working?

 

[05wh250]

Just to update this, I sent the converter in and had it checked, they found nothing wrong with it.

It was definitely not locking, kind of at a loss of where to look now. Only thing I haven't checked electrically is the ground signal from the pcm.

 

[Lt.Dan]

Not sure about 6.0s as it's not my wheel house, but my OBS will not allow the torque converter to lock if a tail light bulb is burnt out, stupidest thing ever.

Try looking for something like that, any reason the truck would not tell the TC to lock.

 

[05wh250]

I know the third brakelight is out because it wouldn't fit with the rollcage and I've got the passenger side air bag out to for the cage and weight, but I'm not sure if any of that would have an affect.

 

[EPA]

Torque converter pressure valve is probably stuck and preventing lock up. Its located in the pump..

 

[05wh250]

Okay, I guess ill try to figure out how to get that apart to check.

 

[Mark Kovalsky]

It was definitely not locking, kind of at a loss of where to look now. Only thing I haven't checked electrically is the ground signal from the pcm.

That's the most likely place to have a problem. You need to electrically check the circuit, don't just look at it and call it good.

 

[05wh250]

That's the most likely place to have a problem. You need to electrically check the circuit, don't just look at it and call it good.

I've ohmed everything out and it all checks out. Is there a way to check that it is switching the ground? Or some other way to check it that I'm not aware of?

 

[Mark Kovalsky]

You can monitor the circuit and see if the PCM grounds it when the converter should lock. I think a better way to check is with Forscan to see if the PCM is commanding the lock or not.

 

[05wh250]

Okay ill try that.

 

[05wh250]

I'm at the track today and it was still hitting the rev limiter on that one specific shift. I thought I had a buddy with access to ids but he doesn't. So I wired in a manual lock up switch and made a practice run, and it didn't hit the rev limiter on the 2-3 shift. But the tow haul light was flashing after I flipped the manual switch, does that mean the pcm side is working? Also, could the solenoid be bad and still ohm out good?

 

[Mark Kovalsky]

The light flashed because the PCM can detect that the circuit is grounded when it doesn't want it to be grounded.

Do I understand this? With the switch on it does what you want, right? If so, the problem is your tuning. It just isn't asking for lock when you want it to be locked.

 

[05wh250]

Yes with the switch on it does what I want. I realized what I posted before didn't make sense after I posted it. I've tried 2 different tuners with the same problem and multiple revisions.

 

[powerlifter405]

OP, if you're unaware Mark knows his way around the 5R110 quite well. I don't want to speak for him but if memory serves me right, he has helped designed some transmissions for Ford. I got my X-plan pin# from him in 2001 off forddiesel dot com when Mark still worked for Ford.
Pick his brain as he's the best bet you have to get free 5R110 advise.

 

[Mark Kovalsky]

I was one of the people that did the programming to operate the 5R110W.

Since this converter is locking with the switch but not without the switch, the problem is either the tuning or a sensor that is sending bad data. If it is a sensor there should be one or more codes that will tell which one is bad.

Tuning is what I did for a living. I can recognize tuning that doesn't work well, and that's what we have here.

 

[Lt.Dan]

I was one of the people that did the programming to operate the 5R110W.

Since this converter is locking with the switch but not without the switch, the problem is either the tuning or a sensor that is sending bad data. If it is a sensor there should be one or more codes that will tell which one is bad.

Tuning is what I did for a living. I can recognize tuning that doesn't work well, and that's what we have here.

Do you do any aftermarket trans tuning? Seems pretty hard to explain to some tuners what you're looking for... lol

 

[05wh250]

I appreciate all the help everyone is giving, especially Mark. We go back racing next weekend so I'm going to datalog it and double check that it is locking. I'm pretty sure it is, I gained almost a tenth and a half. Any suggestions on which sensor might keep it from locking?