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Posted
2 minutes ago, flyingfool said:

or you can try ordering a 2012 Isuzu NPR 4500HD torque converter, this is in one of my trucks and its rock solid, but it doesnt have the clutch system. so no lock up..

1.) How does the computer react to that? 2.) Same stall? 3.) How did you find that out? 

Posted (edited)
10 minutes ago, Grumpy Bear said:

1.) How does the computer react to that? 2.) Same stall? 3.) How did you find that out? 

i have a 2012 NPR 4500HD with 6.0 and 6 speed.  it functions and drives better than my sierra 2500 HD same year and same driveline.

 the NPR never locks up, so it always slips,  and willl increase fuel consumption by 1-2mpg., one will probably have to to disable lock up functions in the software and , plug ports inside the pump housing? I would consult a pro builder with experience with NPR transmissions. 

I cant really say the stall speed is much higher, maybe 600 rpm more. as the sierra truck feels tighter, mind you the NPR has lower gearing in the diff

 

I need to play with my HPtuners and run datalogging on the NPR 

Edited by flyingfool
Posted
13 minutes ago, flyingfool said:

i have a 2012 NPR 4500HD with 6.0 and 6 speed.  it functions and drives better than my sierra 2500 HD same year and same driveline.

 the NPR never locks up, so it always slips,  and willl increase fuel consumption by 1-2mpg., one will probably have to to disable lock up functions in the software and , plug ports inside the pump housing? I would consult a pro builder with experience with NPR transmissions. 

I cant really say the stall speed is much higher, maybe 600 rpm more. as the sierra truck feels tighter, mind you the NPR has lower gearing in the diff

 

I need to play with my HPtuners and run datalogging on the NPR 

I'm waiting :) I love learning more than doing I think. Or I love the results of learning and then doing. :dunno:

Posted

I did the transmission thermostat flip. We took my truck to Knoxville tonight. Ran around a little. We stopped by Chick-Fil-A and sat in line for a few minutes. The trans temp got up to 158*F while in line. That was the highest I saw during the whole trip. We live about 5 miles away from Chick, the temp dropped back down to 153*F before we got home. So it is cooling and maintaining pretty cool. I am pretty happy with that outcome so far. I'll still do my 15k mile one gallon transmission fluid change. It's cheap enough and easy enough and may help. It cannot hurt.

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Posted

I would suggest always having the lock up, non-Lock up has benefits but lock up is best way. If your having to install a converter you should buy a better one TCI/Circle D etc. Just food for thought when a converter is not locked they build more heat then locked ( if the locked converter is working good) I can’t speak from a my truck on no-lockup vs lock up but I can on a few race/street cars and it’s a HUGE difference.


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Posted

Problem solved I installed a tru cool tranny cooler and drove around with my tt hooked and the hottest it got was 160, 125-130 without the trailer thanks everyone 

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  • 2 weeks later...
Posted

May be a dumb question... but... These transmissions were designed to run at 190-220ish degrees. The tolerances open up when it heats up and allows the fluid to lubricate everything. If it is colder the tolerances are tighter and would create premature wear. Right? Similar to getting an engine warm so you don't cold seize it. I am no transmission expert. Right now I am debating changing my own fluid and filter. I have warched the YouTube vids with the Y pipe in the way (sigh). Almost at 45k miles. I drove up mount Washington a few weeks ago and got the trans up to 230. I was a little nervous lol.

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  • Haha 1
Posted
May be a dumb question... but... These transmissions were designed to run at 190-220ish degrees. The tolerances open up when it heats up and allows the fluid to lubricate everything. If it is colder the tolerances are tighter and would create premature wear. Right? Similar to getting an engine warm so you don't cold seize it. I am no transmission expert. Right now I am debating changing my own fluid and filter. I have warched the YouTube vids with the Y pipe in the way (sigh). Almost at 45k miles. I drove up mount Washington a few weeks ago and got the trans up to 230. I was a little nervous lol.

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You don’t need to completely remove the pan to get the filter out. I did it by sliding it all the way to the passenger side which leaves enough room for the filter to come out. Sprayed and wiped out pan clean too.

8d97aa0b248ecbdcc7f796d362872664.jpg
32c3a2f87fb410b6a86e4e76db861568.jpg


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