RFE66 cooling block elimination

[Plumbtired]

Can the 66RFE cooling block be eliminated and two pieces of hose put in its place? Trans is way too hot. Typical I know. I’m seeing 218 degrees in 40 degree weather basically empty.

 

[OC455]

2013-2018 RAM 2500/3500 5.7L/6.4L/6.7L Transmission Fluid Thermal Bypass Valve Ram

Transmission Fluid Thermal Bypass Valve, increase fluid flow to transmission cooler; cooling capacity, easy-to-install billet aluminum; Transmission Fluid Thermal Bypass Valve; Ram Cummins diesel.

ppepower.com

Check this out. Probably what you would need.

 

[crazy jerry]

its not a cooling block. cooler is in front of the radiator

 

[Runaround]

I would also like to know if two hoses could be used in the place of the bypass valve.

 

[Wild one]

I would also like to know if two hoses could be used in the place of the bypass valve.

Back before there were thermostat bypasses available,that's the way i eliminated the thermostat block on my old 13.Just make sure you use good quality transmission cooler hose,and if i remember right (been a dozen years,lol) i think i cut the ends off the hard lines and used a bubble flare tool to add bubble flares to the hard lines

 

[crazy jerry]

Back before there were thermostat bypasses available,that's the way i eliminated the thermostat block on my old 13.Just make sure you use good quality transmission cooler hose,and if i remember right (been a dozen years,lol) i think i cut the ends off the hard lines and used a bubble flare tool to add bubble flares to the hard lines

correct me if im wrong (and i might be).
the thermal bypass as you guys call it , does it not just direct the fluid back to the trans instead of up to the cooler (warming up the trans faster ) no different than the engine thermostat ? then they both open at a set temp allowing the fluid to the cooler.

 

[oledirteh]

it is a trans thermostat. it restricts oil until its at operating temp.

My trans in the 2021 68FRE would run 170-178 when driving normally and i put the bypass in and it ran at 140-145. However if your in a colder climate being to cool can affect your lockup.

 

[Wild one]

correct me if im wrong (and i might be).
the thermal bypass as you guys call it , does it not just direct the fluid back to the trans instead of up to the cooler (warming up the trans faster ) no different than the engine thermostat ? then they both open at a set temp allowing the fluid to the cooler.

The thermostat is there strictly for that little 0.001 milege increase. The RFE's never had a thermostat until FCA went after better milege numbers starting in 13,and the transmissions operated perfectly fine prior to that without a transmission thermostat.If the thermostat went into full flow mode at 155/160 it wouldn't be a big deal,but it doesn't,even when it does open at 170+,it's still a flow restriction,as it still restricts flow to the cooler when fully open.

 

[68PowerWagon]

The thermostat is there strictly for that little 0.001 milege increase. The RFE's never had a thermostat until FCA went after better milege numbers starting in 13,and the transmissions operated perfectly fine prior to that without a transmission thermostat.If the thermostat went into full flow mode at 155/160 it wouldn't be a big deal,but it doesn't,even when it does open at 170+,it's still a flow restriction,as it still restricts flow to the cooler when fully open.

^^^^ What he said. Someone on here did a flow test on it & when fully open it was restricting somewhere around 65%. My temps dropped 20-25* with it out & I didn't feel any difference on how it shifted cold or the mileage. Been meaning to do it on my new truck but haven't found a bypass block with a mounting bracket on it like the original. Probably be fine without it but was hoping to find one with it.

 

[crazy jerry]

i dont tow or haul alot with mine but i did pull 5k (with 37" tires) about 600miles. trans never budged off 170. seems that if the trans tstat is working fine then why go looking for trouble.