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01 1500HD 4L80E Overheating issues

M

Manny1500HD

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I had my transmission guy rebuild me a diesel transmission 4L80e for my 01 1500HD since my original trans the bellhousing ear was broken. plus all my hard part internals had signs of serious heat discoloration and surface cracks i gave him my orignal trans for a diesel trans with him installing the jakes performance rebuid kit. I already had the trucool 40k cooler with no thermostat control and i blocked off my stock radiator fittings for trans. trans has about 1800 miles on it, i live in ca and took a trip up to wrightwood and my trans was hitting 200F which was ok but when i got up a hill which wasnt very steep grade hill at all plus it was like 28F outside in snowing conditions my trans started to go up to 250F while my engine temp dropped from 205F to 150F i was just crusing up the hill at not even 15mph. whats going on?? i plugged in my snap on scanner to check for codes and look at the live data. the 1870 slip count was 0 at all times and TCC Slip Rpm was within specs from what circle D was telling me. the highest i saw on TCC Slip during full open throttle was near 800rpm slip and normal driving only got up to 500rpm slip. i did have the guy install the "shift kit" from Jake's but its still shifitng like stock feel. not sure if he enlarged the plate in the valve body. im running 20x12 wrapped on 33x12.50r20 tires. I'm planning on dropping the pan myself and correcting the shift feel to more firmer. i also dont have the heat shield that sits between the exhaust and transmission lines with my orginal trans wether i had that heat shield or not didnt make a difference in trans temp. what im going to do also is wrap the exhaust near the lines in exhaust wrapping to see if that changes anything. what should i do next? already dumped $2,700 into trans and a new torque conveter 2,200-2,400 stall. stock rear end gear ratio 3.73. even with my stock wheels i'd always have to stop on the pedal on the highways just to keep up.
 
I'm not sure what year core i will try to find out today and not sure if he used the pump that came with this trans or the one from my original. it does have the same location fittings as my original one and i'm not sure if he used the new fittings that came in my kit for that. I did order on amazon fragola npt to an fittings to go to an style fittings soon. I took some pictures of my transmission Driver side Rear View.jpgDriver Side View 1.jpgDriver Side View 3.jpgPassanger side front view.jpgPassanger Side rear view.jpgPassanger Side View.jpgTruCool 40k cooler.jpegPassanger side View 2.jpg
 
So i removed the line and started it up the pressure line puked about quart and 1/4 of transmission oil in bout 5seconds at a steady flow now too much that the hose would fly out of the bucket i had it in. i also pulled the fitting and it threads nicley into case and appears to be the right fitting. i drove it and took me about half hour to try to get it up to nearly 200F to check fluid and i got a consisent reading of the lowest dot in hot level. before i had it at the highest dot level. didnt go over 200
IMG_5447.jpgIMG_5448.jpgIMG_5449.jpgIMG_5452.jpg
 
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I've never had issues with an air bubble getting trapped in a tranny. if your tranny has mileage on it I wouldn't recommend any kind of flushing. re-reading your first post, it seems you had tranny overheating issues before this which would lead me to believe there is an underlying issue with the tranny cooling system. I see your photo posted with what looks like three auxillary coolers behind the gill.

can you show or explain how your cooler lines are routed to the front stack? there may also be an air flow issue through the stack weather it's due to a clogged stack needing cleaned or a faulty fan clutch. how does the color and smell seem with your current fluid, and exactly what type of fluid are you running? if using the dextron 6 which what GM "says" replaced the old dextron 3, dump it and replace with the old dex 3. dex 6 is thinner and the 4l80e doesn't do well with it. others can chime in on that one. but first start with the line routing and air flow through the front stack. plus determining if using multiple coolers on the tranny possibly one might be clogged internally from debris from the previous tranny.
 
Converter slip should be under 50 RPM while in lock up. Anything above that will cause issues and possible overheating.
 
My new rebuilt trans has 2000miles on it. when coverter slip while in lockup is reading 0 acoording to my snap on scasnner and 1870 slip count stays 0 at all times. dbrannon the cooler is new bout 5k miles on it before i put this new one i grabbed my engine gun cleaner from harbor freight and flushed the cooler itself in case of any debris, the way i have it plumbed right now the presssure line coming out to cooler is on the passanger side of cooler and return line is on driver side. the kit came with 23/64 hose that i used. i was test driving it today when i picked up a harbor freight infared camera when i got home my trans was reading 177F and passanger side of cooler is 108F and driver side is 80F. Heres some pictures of my plumbing. also my clutch fan is new just year and half old. planning on converting to eletric fans soon. Its not leaking FYI just left over mess from when i was checking the line if it had flow to coolerIMG_5456.jpgIMG_5455.jpg
 
on the routing, i was referring to if you had the cooler lines going from tranny to the radiator internal cooler to auxiliary cooler and back to the tranny, or if there was a third cooler in the mix. on the stack cleaning. behind those two factory coolers in front of the ac condenser lots of debris will get trapped in there and also between the ac condenser and radiator too. I use a long blow gun with a sharp 90 deg top on my air compressor, pull the upper fan shroud and blow both directions. then get in between the two smaller coolers too. the first time I did this on my truck after I bought it, there was such a mushroom cloud of dust you's think something exploded under the hood!! not saying your's is that bad, but depending on your area and where you drive, it can collect stuff rather quickly.

trans temp at 177 deg F doesn't seem too terrible, how hard and how long did you drive to get there. as for the temp difference of almost 70 degrees between the hottest part of the cooler and the tranny temp sensor, others will need to chime in on that one.
 
on the way back about 45min drive. i WOT 3x times before it jumped from 150 to 177F and if i go out to the desert it'll come up to 200F. I forgot to mention that my shift firmness throughout all the gears are not even firm feels like cvt transmission shifting if you know what i mean only way i know it shifted gears is if i see the rpm drop.
 
that's about how mine feels in shifting. it's smooth. I really don't think 177-200 is too high. others might chime in to verify.
 
I'm confused, you said your TCC slip speed under normal driving only got up to 500rpm in your first post. Thats 10x over max spec... but now your saying its at 0? Was it locked when you were seeing 500rpm of slip?

Did you load it up a hill and check slip speed? That's the best way I've found to diagnose them.
 
Manny1500HD said:
I already had the trucool 40k cooler with no thermostat control and i blocked off my stock radiator fittings for trans. trans has about 1800 miles on it, i live in ca and took a trip up to wrightwood and my trans was hitting 200F which was ok but when i got up a hill which wasnt very steep grade hill at all plus it was like 28F outside in snowing conditions my trans started to go up to 250F while my engine temp dropped from 205F to 150F i was just crusing up the hill at not even 15mph.
Click to expand...

First off it's a lot easier if you LEAN on the enter key a little bit between thoughts so it's easier to follow.

So you are doing 15 MPH. The Torque Converter Clutch is not locked at 15MPH. This is the worst case to make heat as many off road operators will tell you. Esp. towing. This is where I use 4x4 low so the TCC will lock up.

Your engine temperature did what? Stuck thermostat, bad gauge, bit of both?

Good on you to get an IR temp device to verify what's going on.

So you removed the radiator trans oil cooler. Then you put the cooler in front of the stack. Same A/C problem of HEAT reaching that obsolete thermal spring in the fan clutch so it can "DO SOMETHING" like kick the engine driven fan in. Heat from the trans cooler gets removed by the radiator and A/C condenser. The 250F air never reaches the fan clutch thermal spring.

It's 28F outside also making the case to put the trans heat into the radiator because even less really hot air reaches the fan clutch spring. I have had condensers snow clog in blizzards and start to warm up the engine.

Yes I know it's stupid to put the trans oil cooler in the "Cold" side of the radiator and send the heat through the engine before it gets dumped in the radiator. However I can via a brake stand cold (and trans shops warn their techs): The transmission can come up to operating temperature before the engine. Cold engine and severe burns from the transmission. Cold brake stands defrost windshields done within reason.

I believe using the radiator cooler will solve your problems putting the hot oil to it first then additional trans oil cooling through the aux oil to air cooler.

Manny1500HD said:
also my clutch fan is new just year and half old. planning on converting to electric fans soon.
Click to expand...

You may as well rip off the "HD" letters from your truck if you do that. It's one of the differences in later years when electrics were OEM on the Light Duty stuff. HD still has engine driven fans for a good reason.

Best electric fans I have seen are 5,000 CFM for a pair of fans "Freestanding". That is no hood, radiators, engine "airflow restrictions" in the way. Cheaters and a LIE of a rating.

Taking some measurements I calculated a clutch fan to be in excess of 10,000 CFM before the belt started slipping, loudly. (Some gas engine with a too-thin radiator.) Same fan I used in a 6.5 Diesel wasn't enough CFM to keep it cool. I didn't measure the 6.5 Diesel fan that had more pitch (to move more CFM) but your year pickup with like say a Duramax, well, we use fans from that to keep the 6.5TD cool.

An aux pusher fan to help the engine fan isn't a bad idea. Although it can be a restriction via "Windmilling".
 
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Sorry guys moving a bit too qucik here between post. So the snap on scanner is reading TCC SLIP SPEED up to 500rpm while i am starting from a stop 0MPH-60MPH once i get up to 60MPH and its in final gear TCC locks up and scanner now reads 0-3rpm slip ONLY when the TCC locks up. I will try later on today and check my TCC Slip going up a hill.

Diesel Driver the answer to your question yes offroaing will easily get my transmission up to 200F and now im starting to understand why because of a lower speed driving.

WarWagon I'm taking in and understanding what your explaining, its ringing a light in my brain, By any chance were you ever involved in working on aircraft? The term windmilling ringed in my heat from my aircraft class. I'm going to do replumb my trans cooler setup how you explained so in terms of aerodymanics of the heated air hitting the clutch fan thermal spring, "Cause and Effect". What do you mean by routing trans fluid through cold side of radiator? the very lower fitting closets to the floor is the cold side or the one closer to the hood. I am now considering the possiblilty of keeping my clutch fan and changing over to durmax style clutch fan. Also when you were saying cold brake stand? what are you suggesting i do or don't do when cold starting in the morning prior leaving to class? I usually wait 2mins before taking off and letting my engine warm up and trans while driving. Also almost forgot the answer to your question about my engine temperature dropped down fro 209F to 150F when i was climing up the snowy hill. I have not yet verifyed the accuracy of the engine temp gauge will do that later on today but the snapon scanner does match the temp as it says on the dash for trans temp. Talking about gauges reminded me that my entire instrument cluster is not OG the owner i brought it from had put in a escalade dash i been meaning to send it out to someone to get it fully rebuilt due to my engine oil pressure gauge needle bouncing around while crusing speed
 
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