TRNW-2: 42rle never goes past partial lockup

[Healy Powertrain]

Hello Steve, if Actual matches Desired, I think it works as designed?
Whats the TCC slip rpm?
Groaning: You mean Droning? I did a Nitro 3.7/42RLE not long ago and it loved to drone at cruise speeds, assuming it was fully locked up then.
Isnt the partial lockup strategy designed for NVG issues to eliminate the droning and engine vibrations? the 3.7 is a 90deg V6 , I think without a balance shaft, not sure, so it needs all the help in the NVH elimination strategy department?

I think the GM E3C strategy is similar. I happened to datalog a 98 GMC yesterday with a lockup "problem". Its doing that slip thing at light loads but it seems to fully lock at around 55% TCC PWM, gradually increasing % with increasing load all the way to max 96% (WOT).
This GMC lockup problem however turned out to be a Fuel Injection Problem...pfff

Check the exhaust system on that Dakota too, make sure it hangs in rubbers frt to rear and not touching anything.
Have fun!

Marcel Verwijmeren
Healy Powertrain
Driveline Solutions
T 06 57745407
E <info at healypowertrain.com>
W <http://www.healypowertrain.com/>


On Wednesday, September 17, 2025 at 11:56:35 am +02:00, Steve Everett via trnw2 <trnw2 at trnw.net> wrote:

> I have an 05 Dakota with 42rle that I'm trying to solve this lockup issue, built by someone else , and has not been delivered to the customer yet, originally it was kicking in and out of partial lockup randomly, after driving it a couple times we decided to unplug the alternator as it had recently been replaced, that stopped the in and out of lockup, installed a new alternator, no more in and out of lockup issues, but it never goes into full lockup , no matter what speed , driving on level ground , 50-60mph, stays in partial lockup and we can feel and hear the lockup groaning, desired matches actual lockup apply on the scanner, its like the computer isn't telling it , or letting it go to full lockup ?
> 
> I had them pull the valvebody and I checked it over, all checkballs correct, solenoid switch valves replaced using the transgo valves, new dealer solenoid assembly, I'm kind of at a loss on this one, I wanted to replace the tcc reg valve, but the only option is a Sonnax oversize and I don't have access to the reamer for that
> 
> This post from years ago describes exactly what this one is doing, but there are no tsb's that apply to this vehicle
> 
> https://www.trnw.net/trnw/fixdata.php?input=42RLE&aname=17558&confirmed=no&threadID=42RLE-32&cat=tcc#tcc <https://www.trnw.net/trnw/fixdata.php?input=42RLE#content>
> 
> Steve
> 
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