[1772896wtf]

I'm going to be hauling heavy in the mountains and wanted to take steps to keep the 4r100 cool. Will be installing temp gauge t'ed off the cooler line to keep an eye on things. I also wanted to upgrade the 7.3 cooler to the bigger 6.0 cooler (powerstroke), but the price is a deterrent right now (500$).

As i understand the heat is mostly produced in the shear of the converter.

Do you all reckon having the torque converter lockup on a switch, to be activated when hauling up hill in the same gear (2nd and 3rd) would help in mitigating high temps in the tranny?

 

[Mark Kovalsky]

Yes, that will help keep temps lower.

I recommend putting the temp gauge in the test port on the driver's side of the trans. If you install it in the cooler line you're going to see temperatures that are normal but will scare you.

 

[1772896wtf]

Thanks for your reply, mark.
Can you expand a bit on why the temp in cooler line vs test port would be different/better?

Also, can you shift while the converter is locked up?

Also, i read someplace not to lock the converter in first gear, something about it preventing proper fluid flow to the tranny. What do y'all reckon? I like the idea of chugging up steep grades in first or second with the converter locked up, thoughts?

 

[Mark Kovalsky]

Thanks for your reply, mark.
Can you expand a bit on why the temp in cooler line vs test port would be different/better?

The cooler line temp will spike REALLY high when the converter is unlocked. I've seen over 300°F here. The test port will show a good average trans temp.

Also, can you shift while the converter is locked up?

Yes, but it will be a bit bumpy. It's not a problem.

Also, i read someplace not to lock the converter in first gear, something about it preventing proper fluid flow to the tranny. What do y'all reckon? I like the idea of chugging up steep grades in first or second with the converter locked up, thoughts?

The stock calibration will lock the converter in first gear if the go pedal is pressed far enough. It won't prevent proper fluid flow.

 

[1772896wtf]

Mark, thank you so much for your input, I'm feeling quite ready to crawl underneath the truck in the next few days to plumb and wire it all..

 

[69mach1377]

OP, there are aftermarket 6.0 coolers much cheaper that do the job, maybe half the price of OEM. I did the lock up years ago but ever since my hydra chip towing tune, hardly use it anymore. But it is nice to have still.

 

[Bob7.3]

The cooler line temp will spike REALLY high when the converter is unlocked. I've seen over 300°F here. The test port will show a good average trans temp.

Yes, but it will be a bit bumpy. It's not a problem.

The stock calibration will lock the converter in first gear if the go pedal is pressed far enough. It won't prevent proper fluid flow.

Mark, would your answers be different for either of the 7.3 trans models? (Any caveats?)

 

[Mark Kovalsky]

Yes. The C6 didn't have a locking torque converter, so it was always unlocked.

 

[Bob7.3]

Yes. The C6 didn't have a locking torque converter, so it was always unlocked.

Thanks, and apologies for my poorly worded question. Just read the OP a little closer to see you addressed the 4R100 so, I should've asked if the E4OD was the same. But your answer goes all the way back to the C6 so you've covered all of them. Many thanks.

Adding this to my planned mod list.

 

[Mark Kovalsky]

The 4R100 is really a renamed E4OD. They are almost identical.

 

[1772896wtf]

Got the temp gauge wired in, and a switch on the t/c clutch solenoid. Took it for a drive around the neighborhood: handles a lot differently. Imma take it for a longer haul tomorrow and find out.

I am a bit spooked about all the talk of lack of lubrication when t/c locked up in first and second gear. Mark, I'd love to hear you blessings on that one again, and if you had any idea why folks seems to be drumming that up a bunch.

Why is it so flipping hard to read the tranny dipstick 😒

 

[69mach1377]

I found TC LU useful in 2nd while on winding mountain roads around 30-40 mph...but to unlock you have to get down 30 or less.

 

[Steve83]

Why is it so flipping hard to read the tranny dipstick

Because you're not waiting long enough between pulling it out (when it's wet, and trailing fluid up inside the tube) and taking the reading (when you collect that fluid all over the dipstick, and it runs down, blurring the line). To take a reading, the dipstick should be OUT of the tube for at least a minute, so most of the fluid runs back down. Then the dipstick will stay dry, except where it's in the pan's fluid, and the line will be more-obvious.

 

[Mark Kovalsky]

I am a bit spooked about all the talk of lack of lubrication when t/c locked up in first and second gear. Mark, I'd love to hear you blessings on that one again, and if you had any idea why folks seems to be drumming that up a bunch.

That's a new one for me. I've never heard that one before. Maybe someone could explain to me how that happens. I can't see it happening.