I've got a question for anyone who might have experience with this:

The "quick-connect" hoses that attach the transmission cooler to the hard lines have caused a pinhole leak in the hard line itself, right at the interface. I assume this is due to the engine vibration causing the parts to rub and wear on each other over time.

In pricing new sets of lines at the dealership, I found that it would be much cheaper to replace all of it with high-temp hydraulic hose, and after some research found that it's been done before.

So far, it's worked perfectly.

Two changes resulted in the system as a result of swapping the lines:
1) The whole transmission runs 15F cooler, presumably as a result of the lines being routed down the frame rather than in close proximity to the bottom of the block.
2) The transmission lags severely behind the engine in reaching normal operating temperature, for the same reason as above I'd guess. The transmission will be reading about 95F when the engine coolant hits 190F, and takes another 10-15 minutes from that point to hit its usual 140-150.

However, what at first seemed like a benefit now leaves me with a nagging concern...

In the past, the engine and transmission would reach their respective operating temperatures in lock step.

Is there anyone who can speak to whether or not this could pose a danger? I don't have the necessary knowledge or tools to investigate further, but on its face, it seems to me that two very large pieces of metal joined together and heating at different rates may be trouble. Like cracked bell housing trouble. Anyone know???

 

I'll ask at work tomorrow, but I don't think there would be any issues.

 

I forgot to ask before our tranny guy went home.

 

I talked with my co-worker today - he was a Dodge tranny tech for years before moving over to Subaru, and sometime in there he ran his own tranny shop for a while too. He's really good with Dodge transmissions.

What he said is he wouldn't really recommend replacing the hard lines with hose, but it can be done.

He also said that the trans isn't going to be as happy if it's not hot enough - the parts won't swell to proper tolerances and you'll get a lot of fluid bypassing instead of working. Sorry I'm not doing a proper job of describing this - I'm not a trans guy but I'm picking it up as I go. Anyway, he also wanted to know where your temp probe is - is it right where the fluid exits the trans, or on the return line? The temp should be taken as close to the valve body as possible to get the most accurate reading.

Another thing he said is a lot of people run aftermarket trans coolers and actually over-cool the trans, making it not quite as efficient. He recommends running through the aftermarket cooler straight from the trans, then running the fluid though the cooler in the radiator to get it up to engine coolant temps, and then back through to the trans.

Oh, and as far as the temperature increase differential - he said that's not something to be worried about.

 

Thanks so much for the reply!

[Anyway, he also wanted to know where your temp probe is] I installed the temp probe that came with the Edge Juice w/Attitude kit, in the recommended location, in the rear of the transmission. It's actually not very close to either the inlet OR outlet. But its been the same probe taking the same readings from the same location for two years now, so even if it's not in the optimal location, the old readings that were taken vs. the new ones with the new lines were at least obtained with the same method.

[the parts won't swell to proper tolerances and you'll get a lot of fluid bypassing instead of working. Sorry I'm not doing a proper job of describing this ] That makes sense. So it won't operate at peak efficiency until it reaches the correct temperature... which it EVENTUALLY does... just not as quickly as it used to. That's a result I can deal with.

[He recommends running through the aftermarket cooler straight from the trans, then running the fluid though the cooler in the radiator to get it up to engine coolant temps, and then back through to the trans. ] This model (01 Ram 2500/CTD) doesn't seem to have the heat exchanger in the radiator itself, although I did locate what looks to be a heat exchanger unit that interfaces the trans fluid with the engine coolant... located right under the exhaust manifold. It's pretty small, and doesn't seem particularly adept at its function (doubly odd, considering it's placement...?), which should be to raise trans temp quickly and hold them, as your friend described.

[Oh, and as far as the temperature increase differential - he said that's not something to be worried about.] Awesome! That was my biggest concern, modifying something and causing some catastrophic failure.


One last question about this part, though:
[the parts won't swell to proper tolerances and you'll get a lot of fluid bypassing instead of working. ] At this point, the only thing that I'm not clear on is whether this is an efficiency concern (something of so/so importance...) vs. a wear/longevity concern (quite a bit more important...). Does the transmission sustain any additional/abnormal wear when it's operating below peak efficiency at these lowered temps, or is the efficiency loss the only concern?

Thanks again for your help with this!!

 

From what I gathered, it was just an efficiency thing where fluid was bypassing instead of applying force on whatever it is that hasn't reached temp.

Auto transmissions are like voodoo to me, I don't fully understand how the heck they work.

 

[From what I gathered, it was just an efficiency thing where fluid was bypassing instead of applying force on whatever it is that hasn't reached temp.] Ah, perfect. That's exactly what I was looking for.

[Auto transmissions are like voodoo to me, I don't fully understand how the heck they work.] Eh, a lot of it is to me, too. That's why I come here for answers to stuff like this! Someone always knows, or knows someone who does.

Thanks so much for the help!