8hp70 heater bypass

[HvyDuty]

Just got the bypass kit caulk thanks!!!

Is there a how-to on doing this?

do I remove that brass plug to get to it? Thanks!



edit: sorry I go by M2k on 5th Gen forum

 

[caulk04]

Other end. Follow the axis of that plug to the front end of the thermal unit.

There you'll find the snap ring holding the black plastic plug that you need to remove.

 

[Wild one]

Just got the bypass kit caulk thanks!!!

Is there a how-to on doing this?

do I remove that brass plug to get to it? Thanks!

View attachment 248939

edit: sorry I go by M2k on 5th Gen forum

You'll want a decent pair of bent nose snap ring pliars to get the snap ring out.If your truck has a few miles on it,it doesn't hurt to run a wire brush around the inside of the hole the snap ring sits in,before and after you remove the snap ring,then give the plastic plug a good squirt with your choice of penetrating oil.The plug can be a bit of a pain to remove,so you want any build up removed and a bit of lubricant around it's edge doesn't hurt.I used a small pair of side cutters/***** to carefully grab the tit on the plastic plug to wiggle it out.If your truck is a 4X4 remove the front driveshaft,and you'll have to remove the 3 torx screws holding the shifter cable to the tranny,then the shifter cable pops off the transmission,might take a good tug or a bit of prying to get the cable to pop off the stud.

 

[HvyDuty]

Thanks guys I found it, going to tackle it in the morning.

 

[HvyDuty]

Just wrapping it up.Before I button up, that long spring from the back of the original does not go back in on the back of the new thermostat correct?

also, there were two t40 torx bolts holding on my shifter linkage. They were really in there with purple/red locktite.

the driveshaft bolts were 15mm with blue lock tite. Overall not too bad of a job. Excited to see my lower temps combined with my grille ******* mod

Edit: long spring on old goes one new??

 

[HvyDuty]

Hmm I though the results would be lower. I wonder if the 5th gens compensate more



Above is after fully warming up and WOT runs on the highway. Reached max of 195F on trans. Ambient outside temp in the upper 50s

View attachment 248979

 

[HvyDuty]

I did not run the AC if that may make a difference?

 

[grizzstang]

I don’t think you put it in right. From what I remember the long spring does not go back in. I want to say it is just the small rod then your new plug. If you put the long spring under the new plug it would just hold it open and let trans fluid into the heater all the time.


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[HvyDuty]

Yeah I didn’t put the long spring in. When I tried to take it off the original tstat the whole thing fell apart.

I’m stumped no real improvement for me so far.

 

[crazykid1994]

Yeah I didn’t put the long spring in. When I tried to take it off the original tstat the whole thing fell apart.

I’m stumped no real improvement for me so far.

The improvement is lower trans temp which is also beneficial for line pressure and longer transmission life. Possibly even better efficiency in the torque converter. You won’t have any power increase because you didn’t change anything related to making power.

 

[HvyDuty]

The improvement is lower trans temp which is also beneficial for line pressure and longer transmission life. Possibly even better efficiency in the torque converter. You won’t have any power increase because you didn’t change anything related to making power.

Thanks power was not my goal, cooler temps are. Though empty with 3.92 and quad cab it runs like a ***** ape already lol. Ask the newer three series that thought I was racing him during my wot runs lol. He couldn’t hang

I’m just not seeing a drastic change in temps if any at all right now with this modified tstat in my 5th Gen 8hp75...

 

[crazykid1994]

Thanks power was not my goal, cooler temps are. Though empty with 3.92 and quad cab it runs like a ***** ape already lol. Ask the newer three series that thought I was racing him during my wot runs lol. He couldn’t hang

I’m just not seeing a drastic change in temps if any at all right now with this modified tstat in my 5th Gen 8hp75...

What are your temps? Should definitely be lower unless you have the grill shutters still. Those will keep the temps higher. My temps are 132° when fully warmed up cruising.

 

[HvyDuty]

What are your temps? Should definitely be lower unless you have the grill shutters still. Those will keep the temps higher. My temps are 132° when fully warmed up cruising.

I have modded my AGS, only have middle and bottom slats no CEL.

I really beat on it and drove it like I stole it. My high temp posted is after that beating. The lower temp one was me being easy on it to warm up, was hoping it would stay there like you guys

I installed it just like caulks pics. Now I want to go to the 180 tstat. Or Maybe the 5th gens are a pita compared to the 4th gens

 

[HvyDuty]

My truck is a 2021 DT 5.7L no etorque garbage 3.92 quad cab 4x4 big horn.

caulk put down your beer this Memorial Day weekend and post! Lol jk

 

[crazykid1994]

I have modded my AGS, only have middle and bottom slats no CEL.

I really beat on it and drove it like I stole it. My high temp posted is after that beating. The lower temp one was me being easy on it to warm up, was hoping it would stay there like you guys

I installed it just like caulks pics. Now I want to go to the 180 tstat. Or Maybe the 5th gens are a pita compared to the 4th gens

145° beating on it’s pretty good. I hit 152° after 4 back to back 1/4 mile runs. Lol.

 

[caulk04]

Hmm, that's interesting. You are correct in not using any of the springs from the stock part. The plastic cap/plug and the pin are the only parts you reuse.

Did it warm up more slowly than before?

 

[Wild one]

Double post

 

[Wild one]

Today was the first day i've really put any miles on mine on the highway for any length of time,and on average my tranny was running between 115 and 120.That's with the heater assembly completed deleted / deeper PPE tranny pan and my crossover under the tranny pan is double wrapped with header wrap / 160 thermostat and most of the shutters deleted,just top and bottom rows of the shutters left in place.Outdoor temp was 71F with the cruise set between 75 and 85 mph.I sure notice the truck holds 8th gear alot better,hills where it used to downshift to 7th it stays in 8th with the cooler temps.I even did a couple nitrous pulls to about 110 mph for ***** and giggles and the tranny only went to 122F,and as soon as i backed out of it,dropped back down 115 in less then a mile.

 

[HvyDuty]

Hey guys I was easier on it initially than normal and second pic of temps reflect that. I’m goin to wrap the crossover with the left over wrap from my 4th Gen to see if that helps. So far not a drastic diff from before tho I only have a couple k miles in current truck.

 

[HvyDuty]

Today was the first day i've really put any miles on mine on the highway for any length of time,and on average my tranny was running between 115 and 120.That's with the heater assembly completed deleted / deeper PPE tranny pan and my crossover under the tranny pan is double wrapped with header wrap / 160 thermostat and most of the shutters deleted,just top and bottom rows of the shutters left in place.Outdoor temp was 71F with the cruise set between 75 and 85 mph.I sure notice the truck holds 8th gear alot better,hills where it used to downshift to 7th it stays in 8th with the cooler temps.I even did a couple nitrous pulls to about 110 mph for ***** and giggles and the tranny only went to 122F,and as soon as i backed out of it,dropped back down 115 in less then a mile.

I hit the speed limiter hard today it had way more left in it lol