66RFE Transmission - Thermal Bypass Install Help

[HEMIMANN]

I got my RevMax Thermal Bypass Valve Block to replace the OEM with the thermostat in it. I have 2017 Ram 2500 with 6.4L Hemi & 66RFE Chrysler Transmission.

I went to change it today. All was going per plan until it came time to take off the OEM Thermostat Valve Block. The Radiator Cooler end of the Valve Block would not release the oil lines, like all the videos show. The videos show the oil lines easily pulling out of the block, with only an o-ring and a bead to push against.

Mine is completely different - there is some type of connector holding the lines to the block. It looks like some kind of wire ring clip mechanism in a groove. I yanked and twisted - it ain't going nowhere. I tried digging out the wire clip ring, couldn't do it.

Ended up putting it back together after 4 hours of struggle and special tools run. "Easy" half hour retrofit my ass!!!

Any ideas?

 

[Bob Macknight]

from what i saw in those videos those clips need to come off to release the lines watch it again

 

[HEMIMANN]

from what i saw in those videos those clips need to come off to release the lines watch it again

Ok, thanks - I did not see any such activity on the forward connections......just pulling it off. They are difficult to access - they are the side of the block with lines closest together in the wheel well. Even with the wheels turned all the way left, I can barely get my hands up in there. Maybe try a snap ring expander? But it's not a snap ring - it's a thin wire. I've never seen anything like it in 40 years of powertrain work.

 

[HEMIMANN]

Here's the only guy I've found that either acknowledged or showed this bizarre metal retaining clip on the front side of the cooler lines. None of the videos I watched showed it, and the trucks were on lifts with lots of room to work.

1/2 hour and 'simple' my ass.....

https://www.ramforum.com/posts/2051507/
"As for the install what a PITA.

I also had a small Allen wrench that I used to wiggle the damn metal clips off, once started I used the small flat head to pop those suckers loose. They suck, words don’t describe. They are covered with the plastic covers that snap on and off easily."

 

[SeppW]

Need a curved pick like these https://www.amazon.com/Channellock-...1&keywords=curved+pick&qid=1617141674&sr=8-12. to get under the closed end of clip. Untempered imports will bend, break off, etc.

 

[HEMIMANN]

Need a curved pick like these https://www.amazon.com/Channellock-...1&keywords=curved+pick&qid=1617141674&sr=8-12. to get under the closed end of clip. Untempered imports will bend, break off, etc.

Thanks.
I have a set of picks, but unsure if I got them before Craftsman outsourced everything to China. I guess I'll find out, but I'm not going to attempt this mod again until I have some help on a weekend when the weather is nice, seeing as we have to wrestle 2 custom wire clips out. Not sure I can do this with my arthritic fingers, either.

The pipe plugs on the transmission end were simple, after I got the required crow's foot partial wrench ends for the upper plug.

What a kluge.

 

[Maligator]

Thanks.
I have a set of picks, but unsure if I got them before Craftsman outsourced everything to China. I guess I'll find out, but I'm not going to attempt this mod again until I have some help on a weekend when the weather is nice, seeing as we have to wrestle 2 custom wire clips out. Not sure I can do this with my arthritic fingers, either.

The pipe plugs on the transmission end were simple, after I got the required crow's foot partial wrench ends for the upper plug.

What a kluge.

Just an fyi if your revmax is anything like my XDP your really gonna have to pull on those lines to get them into the block it was a bit of a pain on my power wagon. I even specifically bought the xdp bc it says it works with the 66rfe and it does but just barely

also if you live in a cold area you may want to consider the mishimoto bypass. It comes with an interchangeable bypass or thermostat. I live in Md and on cold days my trans temps barely hit 120°. Im leaning towards trying the mishimoto myself

Sent from my Pixel 2 using Tapatalk

 

[wgreggking]

No video of taking off clips but at 3.50 min they snap back on. I used a tiny flat screwdriver to remove them. My truck was raised on ramps, had a foam mat and a cushion for my head,good lighting, warm day, Wasn't easy, just a little tricky. As a retired carpenter,my finger are shot too. Budget plenty of time, I think It took me 1.5 hours, with removal being the worst part.

 

[olyelr]

Im being lazy i guess...but what is this upgrade/mod for?

 

[HEMIMANN]

Im being lazy i guess...but what is this upgrade/mod for?

The better question is what is the OEM part for? It's for some infinitesimal increase in fuel mileage by warming the transmission oil faster than ambient. But it's unreliable and flow-restrictive, many failures, etc., leading to overheated and failed transmissions.

So guys get rid of them and put a retrofit through-flow valve block in place without a thermostat inside.

Clear?

 

[HEMIMANN]

No video of taking off clips but at 3.50 min they snap back on. I used a tiny flat screwdriver to remove them. My truck was raised on ramps, had a foam mat and a cushion for my head,good lighting, warm day, Wasn't easy, just a little tricky. As a retired carpenter,my finger are shot too. Budget plenty of time, I think It took me 1.5 hours, with removal being the worst part.

Thank you for the confirmation. I watched that video too, and never saw the clips or removal. That's why I was surprised when I ran into them. I have a new war plan in place for the weekend, pending weather and my boys availability to help. I'm getting that thing replaced one way or another!

 

[olyelr]

The better question is what is the OEM part for? It's for some infinitesimal increase in fuel mileage by warming the transmission oil faster than ambient. But it's unreliable and flow-restrictive, many failures, etc., leading to overheated and failed transmissions.

So guys get rid of them and put a retrofit through-flow valve block in place without a thermostat inside.

Clear?

Yep, got it! Thanks!

 

[HEMIMANN]

Just an fyi if your revmax is anything like my XDP your really gonna have to pull on those lines to get them into the block it was a bit of a pain on my power wagon. I even specifically bought the xdp bc it says it works with the 66rfe and it does but just barely

also if you live in a cold area you may want to consider the mishimoto bypass. It comes with an interchangeable bypass or thermostat. I live in Md and on cold days my trans temps barely hit 120°. Im leaning towards trying the mishimoto myself

Sent from my Pixel 2 using Tapatalk

Meh - what did we do before this wonderous "fuel economy" transmission oil thermostat was introduce? ANS: nothing.
I'd rather have no thermostat in a small, restrictive oil cooler line. Thanks, but I already bought the RevMax on recommendations on this site. Didn't know about the Mishimoto.

 

[Gr8bawana]

One of these would make the job 100% easier.

 

[EastWestHemi]

There is a YouTube video on removing Chrysler transmission cooler line clips by motorcity mechanic. It’s a bit of a tight spot. I took the bypass off when I moved back east to warm up my transmission faster, it’s easier the second time you do it.

 

[HEMIMANN]

There is a YouTube video on removing Chrysler transmission cooler line clips by motorcity mechanic. It’s a bit of a tight spot. I took the bypass off when I moved back east to warm up my transmission faster, it’s easier the second time you do it.

I went thru a half dozen videos, never saw anyone do anything with any clips, that's why I posted. I've spent an inordinate amount of time on this "easy" retrofit already. I'm prepared for battle this weekend, but thanks anyway.

 

[SeppW]

Im being lazy i guess...but what is this upgrade/mod for?

It serves a purpose as designed, but some say it may get clogged and shut off fluid flow to cooler. Seems the passageway where the thermostat sits is quite narrow and can clog with debris from the transmission clutches disintegrating or other FOD. Somewhere is an article that the 66REF is most efficient at certain temp and I can't recall what that is, maybe 190 degrees? There is a chart somewhere that shows the levels of failure of fluid at different temps, ultimately leading to mechanical failure.

 

[SeppW]

[C]onsider the mishimoto bypass.

Sent from my Pixel 2 using Tapatalk

I searched for Mishimoto on the forum and could not find a post on it. Most people are using TBV replacements made by various diesel aftermarket mfgrs. I went with the Mishimoto and liked how it retains the thermostat, but also includes the bypass valve to run an open TBV if needed. You can also get different degree thermostats. The only thing I don't like about it is the cap material. It appears to be plastic and I'm wondering of the heating and cooling cycle will eventually cause it to get brittle and fail.

 

[mtofell]

Im being lazy i guess...but what is this upgrade/mod for?

I'm with you.... what's the point? I've been hanging out on this board daily for 7+ years and have yet to hear of a problem from one or even an overheating 66rfe for that matter. Sure, it's a POS transmission that shifts like crap and fails for no apparent reason but I've never read or heard about one doing so due this bypass gizmo.

 

[Maligator]

It serves a purpose as designed, but some say it may get clogged and shut off fluid flow to cooler. Seems the passageway where the thermostat sits is quite narrow and can clog with debris from the transmission clutches disintegrating or other FOD. Somewhere is an article that the 66REF is most efficient at certain temp and I can't recall what that is, maybe 190 degrees? There is a chart somewhere that shows the levels of failure of fluid at different temps, ultimately leading to mechanical failure.

This was one of my concerns with a temp thats to low. I know most transmissions have optimal operating temps and that to low can be a bad thing. I think this coming fall I'll swap in the mishimoto just to keep my temps in the 140range in the winter. I think 110° may be a bit cool

Sent from my Pixel 2 using Tapatalk