8hp70 heater bypass

[caulk04]

What's funny is that my last vehicle was an 08 Grand Cherokee with the 5.7 and RFE trans, it ran up to 160 pretty regularly. No heater. I never researched it to see if there was still a thermostat in the cooler circuit (that's not uncommon)

 

[BlownGP]

My 09 with the 4x4 pan and 180 coolant stant is running around 130* in this very cold weather.

In the summer it's around 150-160.

 

[caulk04]

Everybody likes updates. Temps settled here over a 90 minute drive. 500lb load in the bed with some wind drag, fwiw.

Currently have three bypass valves in stock, material on order to do several more.

 

[BlownGP]

View attachment 241258

Everybody likes updates. Temps settled here over a 90 minute drive. 500lb load in the bed with some wind drag, fwiw.

Currently have three bypass valves in stock, material on order to do several more.

That's some nice temps.

I still haven't installed mine yet, kinda nervous fooling with transmission stuff.
But I did change the oil and was snooping around though.

So I see the bracket for the shift linkage. Just take off that torx bit. Kinda slide it out of the way?
Then take some snap ring pillars to pull have the snap ring and the thermostat will pop out?

 

[caulk04]

Yep. Pull the bolts out of that bracket, pop the cable off it's stud then you can get at the thermostat housing. Once that snap ring is out, it might take a little tug on the plastic cap but it'll pop out.

Keep the cap and the pin that fits into the cap, remove the thermostat. Put the new valve over the pin and put it back in the hole. Just make sure the snap ring is seated.

 

[BlownGP]

Yep. Pull the bolts out of that bracket, pop the cable off it's stud then you can get at the thermostat housing. Once that snap ring is out, it might take a little tug on the plastic cap but it'll pop out.

Keep the cap and the pin that fits into the cap, remove the thermostat. Put the new valve over the pin and put it back in the hole. Just make sure the snap ring is seated.

Alright. I will give it a shot this weekend..
Thanks buddy

 

[Wild one]

Alright. I will give it a shot this weekend..
Thanks buddy

Have a clean rag handy to stuff into the hole as soon as you pull the plastic cap,that way,you'll have a little more time and both hands free to get Caulks plug ready to install,and you won't lose enough fluid to have to worry about checking the fluid level afterwards. If you have a set of ramps,it doesn't hurt to drive both the front and rear tire on the drivers side up on them,won't stop the fluid leakage,but will give you more working room under the truck.The shift linkage might need a little bit of a pry ,if it doesn't seem to want to pop off it's stud with a good tug.

 

[caulk04]

FWIW, I stuffed a rag in mine initially then when I pulled it out a couple minutes later it really didn't lose enough to worry about. I bet no more than a shot glass, two tops. Talking a couple ounces, no big whoop. Always a good practice, but I wouldn't get anxious about it.

 

[Wild one]

FWIW, I stuffed a rag in mine initially then when I pulled it out a couple minutes later it really didn't lose enough to worry about. I bet no more than a shot glass, two tops. Talking a couple ounces, no big whoop. Always a good practice, but I wouldn't get anxious about it.

Damn mine lost probably close to a 1/4 quart ,or seemed like that much by the mess it made on the floor,might not have been that much after all,as it is thin tranny fluid,but it sure spread out on the floor like it was alot,lol.I made the mistake of not having a clean rag under the truck,so by the time i got out from under the truck,and grabbed one,i had a hell'va mess under the truck,lol

 

[BlownGP]

Thanks for the tips.

 

[BlownGP]

Damn mine lost probably close to a 1/4 quart ,or seemed like that much by the mess it made on the floor,might not have been that much after all,as it is thin tranny fluid,but it sure spread out on the floor like it was alot,lol.I made the mistake of not having a clean rag under the truck,so by the time i got out from under the truck,and grabbed one,i had a hell'va mess under the truck,lol

Did you end up re filling the trans?

 

[Wild one]

Did you end up re filling the trans?

Mine was apart a couple times,along with having the thermal unit and cooler lines being totally disconnected and disassembled. By the time i was done modding it several times,i was down just about a full quart. But CrazyKid / Caulk and i were also the 3 guys doing the majority of experimenting to get to the final end product,lol. If you do Caulks plug,and use a rag to control the little bit that will leak out,i wouldn't even worry about checking the level afterwards

 

[BlownGP]

Mine was apart a couple times,along with having the thermal unit and cooler lines being totally disconnected and disassembled. By the time i was done modding it several times,i was down just about a full quart. But CrazyKid / Caulk and i were also the 3 guys doing the majority of experimenting to get to the final end product,lol. If you do Caulks plug,and use a rag to control the little bit that will leak out,i wouldn't even worry about checking the level afterwards

Ok, yeah that's what he told me too...

I really need to do this along with a 180 t stat and remove the grille shutters.

I hate seeing these temps. No anywhere close to what my 09 ran at. haah

 

[G-Ride990]

Ok, yeah that's what he told me too...

I really need to do this along with a 180 t stat and remove the grille shutters.

I hate seeing these temps. No anywhere close to what my 09 ran at. haah

Trans it a bit high but the coolant and oil look good to me.

My truck still runs in the mid to low 190s coolant temp with the shutters completely removed and the 180 tstat

 

[caulk04]

I wouldn't worry about the coolant and oil there, that's perfect. Besides, you won't have any control over keeping the coolant that low without a tune and electric fan. You'll be something like 220 before the clutch fan is fully engaged.

Losing the shutters will keep cruising temps down around 195 consistently as is.

 

[BlownGP]

Thanks for tips. I am going to try and do it this weekend.

I finally took it on the highway yesterday and those trans temps crept higher than the 185 it's been staying around.
Got a road trip next month, so I want to see how it does with the new thermostat installed.

 

[Wild one]

Thanks for tips. I am going to try and do it this weekend.

I finally took it on the highway yesterday and those trans temps crept higher than the 185 it's been staying around.
Got a road trip next month, so I want to see how it does with the new thermostat installed.

With a 180 t-stat the coolant should stay right around 185 as long as the trucks moving ,even stopped in rush hour traffic if you still have the clutch fan in place it shouldn't run much over 190'ish.Even unlocked the clutch fan is still spinning and moving a fair bit of air and you'll have noticably cooler coolant temps then you would see with the stock 203 t-stat. Oil temps might not drop as much as you'd expect though,the crank bearings and valve springs are what generate heat in the oil,and neither are all that close to a water jacket to benefit from the lower coolant temps.Pulling the majority of the slats out of the shutters will help keep coolant temps in check,just leave 1 top and 1 bottom slat in on both sides and it won't throw any codes.

 

[CAPnHarley]

Hey if one of these is still available I sure would like one

 

[BlownGP]

Well, I am the middle of doing this and that damn black plastic cap housing does not want to come out. There aint much left of that nipple with me trying to grab it with some pillars. lol
Yes the snap ring is off.

Might try another time with a spare black cap.

 

[Wild one]

I wouldn't worry about the coolant and oil there, that's perfect. Besides, you won't have any control over keeping the coolant that low without a tune and electric fan. You'll be something like 220 before the clutch fan is fully engaged.

Losing the shutters will keep cruising temps down around 195 consistently as is.

Jesse Tim Gracia(sp??) wants one of your bypasses,but he can't post here anymore,so i told him you were on High Performance Rams,if you want to look him up,he wants your paypal info.
Rick