8hp70 heater bypass

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BlownGP

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This IS a nicely engineered part! Come on guys, buy these things up! You WON"T regret it! :)

Best regards,

-Mike

I don't.. That little thing kicks ass.

Even on road trip last month it was 104 outside and trans would stay at 150ish on the highway doing 70mph.
 
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Ghost1500

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I have to ask.... Can this install be done with the truck on Rhino ramps? I have NO lift but I did install the mid and muffler on the ground and the truck was NOT on any ramps but it was a p.i.t.a$$. Thanks for any advice.

Best regards,

-Mike
 
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caulk04

caulk04

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Ohh yeah. A skinny guy could likely do it just on the ground.

Maybe put the ramp behind the front tire though and back up it so you don't have to work around it.
 

Wild one

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I have to ask.... Can this install be done with the truck on Rhino ramps? I have NO lift but I did install the mid and muffler on the ground and the truck was NOT on any ramps but it was a p.i.t.a$$. Thanks for any advice.

Best regards,

-Mike
When i was doing the thermal management unit delete on my 2/4 lowered truck,it was all done off a pair of ramps.
 

Joe _S2013

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I had to run to Cleveland for a few weeks and take care of family. The good news is that my Transmission temps never exceeded 195 Degrees F, no mods(no eliminator installed). The better and most unexpected news was my MPG went from 16.5-17 to 19.5-20. -now a one tank trip from Cleveland to DC. I also learned what is most likely turning the transmission fluid so dark, especially without being burnt or having that smell. The cleaning agents in modern ATF leach the black from the gaskets on the transmission. I learned this from a Chevy dealership, while working on a 6t40 transmission in a Chevy Malibu. I was changing the fluid on my mothers car and noticed how black it was, similar to my truck, so I called the dealership and a mechanic there explained how the synthetic rubber is leached by all the cleaning agents in ATF. -Made sense to me.

I am going to install the eliminator tomorrow, and will do more testing as I have another run to Cleveland scheduled next month if not sooner. I want to see what that does for my temps and MPG.

The clunk is gone, again I believe this was from low Trans fluid level AND temperature. - The first thing is to make sure your transmission temperatures are not going above 185-195 degrees under normal driving conditions (no towing). Yes, my clunk was there until I did this fill process, but something was causing my truck to run hot (230 -260), and that I believe was the biggest cause of the clunk, as I am sure the fluid temps was affecting how the transmission operated. - I also believe this has to do with the Transmission Heater Assembly (THA). As most on here know the THA must be replaced as a whole unit and Dodge does not sell the thermostat separately, I found the metal tubes and O-rings that connect the heater to the transmission are discontinued (out of stock without replacement). However, not to worry as the new THA comes complete, thermostat and tubes (no o-rings required). -There was a service bulletin on these tubes leaking and I believe mine were leaking, this last winter I saw greenish fluid on the snow under my truck, I did not know what it was at the time, but since getting on here and learning the color of transmission fluid I am sure that is what it was. -I use the orange coolant, so I know it was not coolant. Also, I go to the carwash regularly and get the undercarriage cleaned so I did not have ATF leak stains.

If you are having issues with transmission temps being too high, regularly over 200 under normal driving conditions, Clunk when coming to a stop (feels like being lightly rear-ended), transmission slip/ hard shift feeling in higher gears, and your drive train is no longer under warranty (don't void your warranty) I recommend doing a filter and fluid change and replacing your THA (at 139.00 it is the cheapest part of this process). Mine is a different truck after this. I set my cruise at 82MPH on the PA turnpike and 78MPH on the Ohio turnpike with outside temps ranging from mid 70's to Mid 90's and my transmission temps never got above 193 including going up hills and hard acceleration to pass many trucks.
 
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Joe _S2013

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Here is how I check my ATF fill level, keep in mind I have a sloped driveway that allows me to get the Transmission, not just the truck, level:

***** I AM NOT A CERTIFIED MECHANIC! PERFORM THE BELOW AT YOUR OWN DISCRETION What worked for me might not necessarily work for you.*****

1. The night before I am going to do the level check/fill, I use a small level (often called a torpedo level) and place it on the transmission rails and several other locations, running the length of the transmission, to ensure the TRANMISSION is level. I use my tailgate and 3ft level to find level side to side, I don't think this is as important but you do want to be as close to level from side to side as possible. These two adjustments can take sometime and in the Va Summer heat the transmission temps are out of spec before I get to level, again why I do it the night before.

2. Once the transmission is level from front to back and side to side I place bricks behind the rear tires, and I use chalk to mark the location of each tire on the driveway, -all four side of each tire. This allows me to get it back to level quickly when doing the check/fill procedure.

3. Before calling it night make sure you set your display to show the screen with the transmission temperature. If you are using an OBDII device and app then make sure it is working and you know where to check transmission temps from. I just used the trucks display, as I have not notices any difference between my truck and my OBD II app.

4. The morning of I get up early about 6am, for a couple of reasons, the outside temps are cooler, the sun is not as hot and I don't have to worry about my neighbors, as I am going to be rapidly accelerating through the neighborhood to get the truck through all the gears.

5. I verify that the transmission is level again (front to back and side to side), no reason it is not but never hurts to check again. Also verify i can easily see my marks from the drivers seat.

6. Loosen the fill/check plug so that it is only hand tight and will be easy to remove, but will not fall out when driving the truck or become too loose and leak. I use marks that I have made on the plug and transmission. This also makes sure you can get the plug out, again this was the longest and biggest PIA for me when doing this, and I had to notch my plug and use a hammer and punch to brake the seal on the threads. -if you strip it and cant get it out, YouTube offers a few different ways to do it.

7. Now make sure you are ready to fill by having an insulated welders glove (the fill plug is inches away from the exhaust pipe and the engine will be running while you do the check/fill); a quart of your transmission fluid of choice (I recommend the Mopar stuff, as I have explained before why); whatever fill device best for you to fill the transmission (I recommend the modified garden sprayer fill device (with the fluid in it and pressurized) it was easy to make and made filling quick and easy); also, have your torpedo level, you will want to verify the transmission is level again once you are done driving the truck.

8. Once you have verified everything is set up to go and you can get the truck back to the same spot quickly it is Go time. - Remember, Once you start the truck you are on the clock and need to make sure everything is setup so you don't waste time.

9. Start the truck and verify the display shows temps for transmission, if you did this the night before then it should still be on the same screen. I have a route of about 1/2 mile that allows me to get the truck up to 100 -110 degrees and accelerate through the gears including reverse.

10. Pull back into the driveway and align the tires back up with the bricks and chalk marks. Place the parking brake on, and with the truck in park and running, I quickly put on the welding glove, grab the fill device (a modified garden sprayer with prefilled with transmission fluid and pressurized), grab my level and tools to remove the fill plug. Check the trucks display and verify you are still below 120 degrees. It is better if you can have someone sitting in the truck reading the temp to you. -My wife loves waking up at 6am to read this for me. lol

11. Quickly slide under the truck and check the transmission level, if not level you will need to get it level before getting out of temperature range. Remove the plug if no fluid is coming out add fluid with the fill device until it just starts to trickle/drip out. Then reinstall the plug. -Not as easy as it sounds with a welders glove on and hot as he'll exhaust inches away from your hand and arm, but definitely doable.

12. I did not have to do this, but I would recommend using your OBD II device to reset the computer, since the transmission learns how you drive this should cause it to go into the relearn mode.
 

hawsk99gt

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just a quick question regarding temperature. What should the OIL & COOLANT temps be? And Oil Pressure, what numbers are you getting for this? I noticed my coolant jumping all the way to 219* and my oil temps running at 222*. My oil pressure will get to 55psi. Now the coolant will drop to 199* but bounce up to 217 - 219. Just wondering if this could be contributing to high heat to the transmission. But I will say I did a 120 mile round trip to Atlanta and back and my trans temps stayed within range. Hottest it got was 175*F. Temps outside were around 91*F.
 

HEMIMANN

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just a quick question regarding temperature. What should the OIL & COOLANT temps be? And Oil Pressure, what numbers are you getting for this? I noticed my coolant jumping all the way to 219* and my oil temps running at 222*. My oil pressure will get to 55psi. Now the coolant will drop to 199* but bounce up to 217 - 219. Just wondering if this could be contributing to high heat to the transmission. But I will say I did a 120 mile round trip to Atlanta and back and my trans temps stayed within range. Hottest it got was 175*F. Temps outside were around 91*F.

Your coolant temps are fine with the stock 200 deg F thermostat. 220F considered max, 210F avg in moderate outside temps.

The problem isn't the coolant - it's the transmission oil being heated up artificially by the oil cooler thermostat...which had never been used until recently in the never-ending search for infinitesimal fuel economy improvements to meet every more stringent US EPA fuel economy increases regulations.

Many of us have gotten rid of that gizmo and install a "bypass" block which is really just a re-connector without a thermostat.

If your tranny is a ZF 8 speed, see @caulk04 for his bypass kit.
If your tranny is a Chrysler RFE, you can get the kit from RevMax or ATS (google).

I lose track of all the truck model year change dates.
 

Ghost1500

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Just a quick question regarding temperature. What should the OIL & COOLANT temps be? And Oil Pressure, what numbers are you getting for this?
I just did a liquiMoly engine flush and new oil change. These numbers are after those two things. The outside temp was 88 degrees and extremely humid too. For coolant temps I never went over 199 and it fluctuated between 195 to 199. This was in city and highway driving. The oil temps were at 208 and the trans temps never went over 188 degrees (dead stop) but hovered around 176 to 181. And I have NOT put in my trans thermostat mod yet. My oil pressure at the highest was 62 lbs and at the lowest 48. I hope this helped?

Best regards,

-Mike
 

Wild one

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I just did a liquiMoly engine flush and new oil change. These numbers are after those two things. The outside temp was 88 degrees and extremely humid too. For coolant temps I never went over 199 and it fluctuated between 195 to 199. This was in city and highway driving. The oil temps were at 208 and the trans temps never went over 188 degrees (dead stop) but hovered around 176 to 181. And I have NOT put in my trans thermostat mod yet. My oil pressure at the highest was 62 lbs and at the lowest 48. I hope this helped?

Best regards,

-Mike
I would guess your Dad might have installed a 190 thermostat with those coolant temps Mike
 

hawsk99gt

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I just did a liquiMoly engine flush and new oil change. These numbers are after those two things. The outside temp was 88 degrees and extremely humid too. For coolant temps I never went over 199 and it fluctuated between 195 to 199. This was in city and highway driving. The oil temps were at 208 and the trans temps never went over 188 degrees (dead stop) but hovered around 176 to 181. And I have NOT put in my trans thermostat mod yet. My oil pressure at the highest was 62 lbs and at the lowest 48. I hope this helped?

Best regards,

-Mike
Thanks for the input, I already have CAULK04's thermo by pass installed and it usually works well, actually it has prevented my truck from reaching the temps it use to get from highway driving which was up too 275*. But as far as my oil it has been Mobile1 full synthetic 5w20 since the first oil change. And since my last 2 oil changes I have added a quart of Lucas Full Synthetic additive to prevent any wear on the lifters. So 6 QTS of Mobile1 and 1 QT of Lucas. I am at 93K miles probably need to replace my TSAT at some point soon
 

Ghost1500

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I would guess your Dad might have installed a 190 thermostat with those coolant temps Mike
That'd be cool. No pun intended.... The highest I have seen in the truck was 203, never ever above that. The latest numbers I quoted above were on today's trip. It was about 35 miles of city/hwy driving.

Br,

-Mike
 

Ghost1500

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On a stock tune, what's the lowest temp thermo. I can run without setting a code? Thanks in advance.

Best regards,

-Mike
 

Wild one

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On a stock tune, what's the lowest temp thermo. I can run without setting a code? Thanks in advance.

Best regards,

-Mike
180,but if it's a daily driver a 190 is probably the better choice on the stock tune.Do not remove the factory mechanical fan if you're not going to tune it. If you're seeing coolant temps between 195 and 200 after a decent drive on a hot day, i'd leave it alone Mike.
 
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