8hp70 heater bypass

[CanuckRam1313]

I had one in my 19' for a good while and the trans temps were reduced typically by 30deg/c at full operating temps.
I have one now in my new 23' for call it a month, and again, temps down by around 30deg/c.

The other thing I notice is that my engine coolant temps are down a few deg/c as well, on my 23' and the same before on my 19'.

The transmission is so much happier, shifts firmer and smoother, and just feels better overall.

I'll still do my trans oil & filter change at about 60,000Km's, just because!

 

[Lysergic]

Did the @caulk04 bypass install on the truck today. Just under 600 miles on the new girl, so she's starting life with a cooled down ZF. Thought I would post a few pics and add my $0.02 to the installation commentary.

Tools I used:

1. Cordless impact and a 15mm socket to drop the end of the front driveshaft. Easy-peasy removal with impact tools.
2. Flat blade screwdriver. Mine was 10mm.
3. Quality snap ring pliers with 90° tips.
3. Torx T40 bit.
4. Long-handled 90° needle nose pliers.
5. Torque wrench.


Removal of the cable bracket. Once you have the T40 bolts holding the bracket out, use the flat blade screwdriver between the post on the lever and the plastic connector. Gently pry the connector while pulling it with your free hand. It should pop right off. and you can swing the entire bracket assembly out of the way.

Snap ring pliers... I have a good pair, but the factory installation of the snap ring holes was vertical, and the body/hinge mechanism of the pliers was hitting the heater which interfered with getting the pliers square to the snap ring and plug hole. The 90° bend in the tips was *almost* too short to reach the snap ring holes. I finally managed to engage the snap ring and spin it 90° towards the passenger side of the vehicle. After that, I had plenty of space for the pliers to operate correctly. Reinstallation was... a snap.

Removal of the plug. I was a bit concerned about this due to comments from previous posters, but on my vehicle I used some Harbor Fright long-handled 90° pliers I picked up about ten years ago. Never had a use for them until today. My pair had some really good ridges on the nose to "bite" into the nub on the plug. The plug slid right out on mine with no scuffing or visible damage to the nub. Doesn't look like it was ever removed.

I put the front end up on ramps a few hours before performing the work, my thought being the trans fluid would gather towards the rear of the transmission. The fluid that ran out before I could jam a rag into the hole was very minimal. Not enough to bother going through a fill & check procedure. I thought ATF+4 smelled bad, that ZF green stuff really STINKS! I won't complain about ATF+4 ever again..

Everything went back together without issue. Snap ring checked and double checked. Normal running temperatures pre-bypass have been averaging 185°F. I'll be taking a 140 mile trip (all highway) back into Houston on Monday morning. I'll check back in to report the new highway average.

Here's a few pics:

Cable connector removed:



The 90° pliers I referenced (highly recommended for pulling the plug):



These rest of this post is not related to the bypass install, but here's an underside shot of the trans pan on the EcoD. There's nothing in the way for pan removal, HOWEVER, I'm going to have to get very creative refilling the transmission when I do a flush in another 50K mi. The distance between the fill plug and that DPF is about as wide as my finger. At present, I don't have a tool that I could fit up there to the plug.



The fill plug is directly above and to the right of the tip of my finger. Finger is pushing on the DPF insulation blanket. No clue what tool I could get up there that would fit and not bind up when backing out the plug. Someone posted a video on YT with a fluid change on a 2020 EcoD where he used the plug on the driver side of the vehicle. Link: https://www.youtube.com/watch?v=4_CMkSmLut4 That plug is visible in my first photo above of the cable connector. Easy access BUT... I don't know if the bottom of the plug is at the same distance from the bottom of the transmission as the inaccessible plug on the passenger side. If it is not, I would think this would affect the fluid level measurement in the transmission. I need to go back under and measure it. Will report my findings later.



Ok, and now is where all you Hemi owners can start throwing rocks at me.

 

[Lysergic]

Made the long trip into town. Running 75MPH on the freeway, trans temp was floating between 152°-158°F. 80°F outside temperature at 4AM. Ugh..summer.

That's a good 30° cooler than what I was seeing before the bypass. When I exited the freeway and was on city streets, it stayed about the same.

 

[BlownGP]

Did the @caulk04 bypass install on the truck today. Just under 600 miles on the new girl, so she's starting life with a cooled down ZF. Thought I would post a few pics and add my $0.02 to the installation commentary.

Tools I used:

1. Cordless impact and a 15mm socket to drop the end of the front driveshaft. Easy-peasy removal with impact tools.
2. Flat blade screwdriver. Mine was 10mm.
3. Quality snap ring pliers with 90° tips.
3. Torx T40 bit.
4. Long-handled 90° needle nose pliers.
5. Torque wrench.


Removal of the cable bracket. Once you have the T40 bolts holding the bracket out, use the flat blade screwdriver between the post on the lever and the plastic connector. Gently pry the connector while pulling it with your free hand. It should pop right off. and you can swing the entire bracket assembly out of the way.

Snap ring pliers... I have a good pair, but the factory installation of the snap ring holes was vertical, and the body/hinge mechanism of the pliers was hitting the heater which interfered with getting the pliers square to the snap ring and plug hole. The 90° bend in the tips was *almost* too short to reach the snap ring holes. I finally managed to engage the snap ring and spin it 90° towards the passenger side of the vehicle. After that, I had plenty of space for the pliers to operate correctly. Reinstallation was... a snap.

Removal of the plug. I was a bit concerned about this due to comments from previous posters, but on my vehicle I used some Harbor Fright long-handled 90° pliers I picked up about ten years ago. Never had a use for them until today. My pair had some really good ridges on the nose to "bite" into the nub on the plug. The plug slid right out on mine with no scuffing or visible damage to the nub. Doesn't look like it was ever removed.

I put the front end up on ramps a few hours before performing the work, my thought being the trans fluid would gather towards the rear of the transmission. The fluid that ran out before I could jam a rag into the hole was very minimal. Not enough to bother going through a fill & check procedure. I thought ATF+4 smelled bad, that ZF green stuff really STINKS! I won't complain about ATF+4 ever again..

Everything went back together without issue. Snap ring checked and double checked. Normal running temperatures pre-bypass have been averaging 185°F. I'll be taking a 140 mile trip (all highway) back into Houston on Monday morning. I'll check back in to report the new highway average.

Here's a few pics:

Cable connector removed:

View attachment 545229

The 90° pliers I referenced (highly recommended for pulling the plug):

View attachment 545230

These rest of this post is not related to the bypass install, but here's an underside shot of the trans pan on the EcoD. There's nothing in the way for pan removal, HOWEVER, I'm going to have to get very creative refilling the transmission when I do a flush in another 50K mi. The distance between the fill plug and that DPF is about as wide as my finger. At present, I don't have a tool that I could fit up there to the plug.

View attachment 545231

The fill plug is directly above and to the right of the tip of my finger. Finger is pushing on the DPF insulation blanket. No clue what tool I could get up there that would fit and not bind up when backing out the plug. Someone posted a video on YT with a fluid change on a 2020 EcoD where he used the plug on the driver side of the vehicle. Link: https://www.youtube.com/watch?v=4_CMkSmLut4 That plug is visible in my first photo above of the cable connector. Easy access BUT... I don't know if the bottom of the plug is at the same distance from the bottom of the transmission as the inaccessible plug on the passenger side. If it is not, I would think this would affect the fluid level measurement in the transmission. I need to go back under and measure it. Will report my findings later.

View attachment 545234

Ok, and now is where all you Hemi owners can start throwing rocks at me.

View attachment 545235

Good tip on the pliers. I was one that had problems getting the plug out, but I was using straight pliers. 90* would have been better.

Glad it's working for you. It's a great mod!!!

 

[Hanover Fiste]

I installed mine today. I was hoping it would take about 15 minutes or so; it ended up being almost an hour due to unforeseen circumstances.

The transmission cable came off easily. However, the snap ring holes were in the 8 o'clock position, which made it almost impossible for my snap ring pliers to fit without hitting something. Luckily, my snap ring pliers have adjustable tips, so I was able to extend one leg slightly longer than the other to remove the ring.

The bypass went in OK, but it had a lot more spring pressure than expected. After I pushed it into the hole, I went to grab my pliers, and the entire assembly popped out, landing almost in front of the truck. I tried to devise different methods to get the snap ring installed while holding the plug in. At times, I felt like I needed 3 hands to do the job. Then, almost miraculously, the plug stayed in its place, and the snap ring went into the groove on the first try. I must have checked about a dozen times to see if the snap ring was fully seated. After that, reassembly was a breeze.

I'll drive it tomorrow to see how the temps are.

EDIT: I drove it a short while today, and the highest temperature I saw was ~160 degrees; it's usually 185-190 degrees. It seemed the oil and coolant temperatures were about 10 degrees cooler as well.

EDIT #2: I drove it back and forth to work (21 miles each way), in 100-degree weather during the day (mid 80s at night) and the transmission temperature didn't exceed 141 degrees. It seems the faster I went, the cooler the temperature of the fluid.

 

[Lysergic]

EDIT: I drove it a short while today, and the highest temperature I saw was ~160 degrees; it's usually 185-190 degrees. It seemed the oil and coolant temperatures were about 10 degrees cooler as well.

EDIT #2: I drove it back and forth to work (21 miles each way), in 100-degree weather during the day (mid 80s at night) and the transmission temperature didn't exceed 141 degrees. It seems the faster I went, the cooler the temperature of the fluid.

What I've noticed so far is opposite of your experience. Cruising down the highway the temperatures are bit higher but noticeably fluctuate with the Active Shutter system working. Coolant temps will get up to around 212°F, start dropping to around 204°F, then slowly climb back up. This is a constant see-saw while travelling at 70-75MPH. Transmission temps float between 150° & 160°F in sync with the coolant temperature rise and drop.

My old 2012 Ram exhibits the opposite condition. It runs cooler when flying down the highway.

 

[BenchTest]

I was just under my truck checking out the possibility and logistics of doing this bypass. I noticed the heater unit on my Ram-O-Matic 8speed had 4 of the mounting bolts backed off. Glad I decided to look under here. 1 bolt was a full 2 turns backed out from the flange making contact with the heater unit, the other 3 were around 2/3 of a turn backed off. That doesn't instill a lot of confidence. 84k on the truck. Wonder what else has backed off.... might be worth checking into this on your truck folks.

 

[NETim]

I installed the caulk04 bypass on my '14. It worked but the ZF took forever to warm up, especially in cold weather.

So, I installed a cooler bypass, which allows the ZF to warm faster and max out at roughly 170F in my use in hot weather.

I am happy with what these two mods did for the ZF.

https://www.ebay.com/itm/2961144644...tOh_fBTS_q&var=&widget_ver=artemis&media=COPY

 

[BlownGP]

What I've noticed so far is opposite of your experience. Cruising down the highway the temperatures are bit higher but noticeably fluctuate with the Active Shutter system working. Coolant temps will get up to around 212°F, start dropping to around 204°F, then slowly climb back up. This is a constant see-saw while travelling at 70-75MPH. Transmission temps float between 150° & 160°F in sync with the coolant temperature rise and drop.

My old 2012 Ram exhibits the opposite condition. It runs cooler when flying down the highway.

As you probably know the grille shutters are making it run hotter on the highway. They close.

I took mine off, like I had a 2009 Ram and it always ran cool with a 180 thermostat. If I cared that much about MPG I would have got a Ridgeline or Santa Cruze truck

 

[Lysergic]

As you probably know the grille shutters are making it run hotter on the highway. They close.

I took mine off, like I had a 2009 Ram and it always ran cool with a 180 thermostat. If I cared that much about MPG I would have got a Ridgeline or Santa Cruze truck

Yep. I'm ok with the slightly higher temp - it's a diesel.

 

[skates15]

Failed install. I have a 23 1500, 4WD, followed the instructions from your auto huckleberry (which are great) and I failed to get the black plug out.

The pictures from the documentation show the plug has a nipple on it so that you can grab it via pliers and get a bite on it but my plug is completely smooth on the face. The only way to get it out is to drill it or super glue a nail to it and try to pull it out.

I didn't have time.

@caulk04 any thoughts on how to proceed or a part number for the plug so.I can order one in event I destroy the original getting it out?

I got the snap ring off, no problem and I do have 90 degree pliers, but again, there is nothing to bite into on the plug!

Any help would be appreciated, so close.

 

[Shawn Burns]

I had the same issue. I ran a screw into mine at a shallow depth and was able to pull mine out. I was admittedly sweating bullets.

 

[skates15]

I had the same issue. I ran a screw into mine at a shallow depth and was able to pull mine out. I was admittedly sweating bullets.

Thanks. I thought of doing that but would prefer to have a replacement plug on hand just in case.

 

[Wild one]

Thanks. I thought of doing that but would prefer to have a replacement plug on hand just in case.

I don't think the plug is a servicable part,the only way my local parts department could get the plug,was to order a complete thermal management unit

 

[skates15]

I don't think the plug is a servicable part,the only way my local parts department could get the plug,was to order a complete thermal management unit

I've tried searching for thermal management unit or cooler and no luck. Can you tell me what you searched for?

 

[skates15]

Anyone have ideas on how to get the plug out with the surface being flat and nothing to bite into? I.don't want to drill into it without a replacement.

@caulk04 can I return your bypass if my only option is to drill out the plug? I was expecting the plug to have the nipple on it as per the pictures in your document, but this isn't the case and the only way to get it out is to destroy it and apparently order a complete thermal management unit just to get a replacement plug.

 

[MRFREEZE57]

I've tried searching for thermal management unit or cooler and no luck. Can you tell me what you searched for?

Try cleaning out around the area where the plug is inserted, maybe try tapping it to loosen it up. the plug on my truck just launched out of there once the snap ring was removed.

 

[Wild one]

Anyone have ideas on how to get the plug out with the surface being flat and nothing to bite into? I.don't want to drill into it without a replacement.

@caulk04 can I return your bypass if my only option is to drill out the plug? I was expecting the plug to have the nipple on it as per the pictures in your document, but this isn't the case and the only way to get it out is to destroy it and apparently order a complete thermal management unit just to get a replacement plug.

Clean the crap out of the plug,scuff it up with some 180 grit sandpaper,and JB Weld a nail or screw to it,use the old style "original" JB Weld,not the 5 minute stuff. A cleaned up and sanded nail head will stick good to the plug,if you're scared to run a screw into the plug. Any hole you do leave in the plug can be repaired with JB Weld.

 

[caulk04]

Those cheeky little farts. Hmmm.

You might could epoxy something to the plug to pull on. Or I've heard of people having trouble start the truck to generate some pressure to help. I'd recommend two people so you can shut the truck off immediately if it works.

The stock thermostat has a pretty hefty spring behind it, more than once I've been contacted by people having trouble removing the plug, only to have it pop out on its own while they were contemplating life

As for returns, you'll have to get ahold of Dillyn at Huckleberry.

 

[JHoward]

Anyone have ideas on how to get the plug out with the surface being flat and nothing to bite into? I.don't want to drill into it without a replacement.

@caulk04 can I return your bypass if my only option is to drill out the plug? I was expecting the plug to have the nipple on it as per the pictures in your document, but this isn't the case and the only way to get it out is to destroy it and apparently order a complete thermal management unit just to get a replacement plug.

I don't understand this ... when I removed the "snap ring", my "plug" shot out spraying me with an shot of tranny fluid ... tastes horrible ...

There's bound to to be an simple solution to get the "plug" out as it's not being forcefully held in place by removing the "snap ring" ...?