towing/hauling with 4L80E & fluid type/Cooling system ?'s

[docdray]

with tubes and no fins to radiate heat off, I really dont know how much heat it would shed, not enough air flow through tubes.IMO, I think something with rapid heat dispersal is needed.

 

[buddy]

I think the tubes are so that air travels all the way across the bottom of the pan, rather than hitting the pan and flowing around it, maybe a little more heat transfer. Im sure it will help a little.

 

[M123KT-450]

Buddy gets it

Yes Thats perfectly how it works. . .the extre 3QT's gives you more volume so that keeps temps down. . .with the pan a few inches lower them tubes flow more under truck air. . .also cooling the fluid now with the stock cooler doing its deal and synthetic fluid the trans should be just fine>

Mike

 

[M123KT-450]

So is there anything else one should know about running these 4L80E's ?

I think the GM cooler is plenty good as i have an 18,000GVW cooler the GM one is by far bigger so i am going to leave the stock cooler.

Any more thoughts on the Trans cooling pan ?

Mike

 

[M123KT-450]

So anywho thoughts on this Trans pan cooler ?

Mikey

 

[DennisG01]

So anywho thoughts on this Trans pan cooler ?

Mikey

I think in order for those tubes to effective, you'd have to have air being forced straight at them - parallel, too. Now I haven't seen any results of under-truck aerodynamics, but I'm going to take a wild guess and say the air flowing under the truck will be anything but smooth, let alone parallel to the tubes.

 

[M123KT-450]

Now Wouldn't the extra 3 quarts of fluid still be a plus ?

As more volume will take longer to heat up and prolly run a little cooler ?

I know I have have dropped engine oil temps by putting on larger oil pans n running bigger oil filters .

Wouldn't the same effect happen ?

Mikey

 

[buddy]

Yes, you will have a positive effect with the pan. I would expect that the tube would help as it is lower in the stream.

The point is that it will catch the air, and the tubes force it to travel all the way across the tranny instead of just hitting the pan and diverting somewhere else in turbulence.

 

[M123KT-450]

Thats what i was thinking as well but worst case i just hold an extra 3 bottles of fluid. . .

Mikey

 

[DennisG01]

Yes, you will have a positive effect with the pan. I would expect that the tube would help as it is lower in the stream.

The point is that it will catch the air, and the tubes force it to travel all the way across the tranny instead of just hitting the pan and diverting somewhere else in turbulence.

Well that's what I was starting to think about - I've seen those pans before and always thought they were a neat idea. But the more I think about it, I'm not convinced that the tubes would have any effect. Now this is just theory, so bear with me. Air is a fluid. Fluids follow the path of least resistance. Even if the pan happens to sit in such a way that it gets a smooth flow of air coming at it, at just the right angle, the air rushing at the pan would certainly have an easier time going under and around it than through those little tubes.

Here's an idea: Take a large shoe box and attach straws to the bottom - hold it out the window (might be best to have someone else drive) and see if any air comes through the straws. Obviously the air flow outside of the window is better than under the truck, but if it doesn't work out the window, it surely won't work under the truck. It might be very hard to tell if the air is coming through the straws or around them, but get creative! If nothing else, it'd be a fun experiment.

But, like you guys said, at the bare minimum, you'll at least have the benefits of the extra 3 quarts.

 

[M123KT-450]

yea i am thinking that very thing the extra volume won't hurt anything.
worst case the transmission still goes bad after a few years of towing.

Mikey

 

[DennisG01]

The 4L80's are pretty stout. Keep the temps down (get a good tranny gauge), drive sensibly and it should serve you well. Yours is a '95? I think you can do the TC lock-up mod. I know it's been talked about here - probably can find it with the search function. There's also a how-to on Heath's technical blog.

 

[M123KT-450]

Oh i hear you on keeping the Temps down.
This is why i'm looking into synthetic fluid and the cooling Pans.

I'm sure the Huge Cooler up front the size of the Engine oil cooler is doing a fine job but I have had way to many Auto trans failures so i would like to run a little of everything even if it seems like over kill . . . .

The Radiator style cooler.

The pan cooler.

Synthetic fluids.

I have synthetic Oil in the motor which has drop Engine water temp 12*F so that should also have dropped the trans temp some. Idealy all the Lubes in this Truck will SYN soon enough. . .

Truck is also going to be Regeared from 4.10s to 4.56s as i don't drive fast so the little extra gear with synthetic lube should make the truck a good bit easier to roll. . .

Oh yea i'm going threw the whole truck axles T-case transmission this thing will one stout workible towing Rig. . .

Mikey

 

[M123KT-450]

whats the volume on the 4L80E ? how much AFT dose this unit hold ?

Mikey

 

[docdray]

AFT??????WTF----------11.5 qts on tranny only, then figure aux cooler, lines, and any other additions.

 

[M123KT-450]

Now whats the best way to change out the ATF ?

Mikey

 

[rlb]

GM's stance according to the label they put in the door jam is to NEVER tow in OD, always put it into D. Now if you have 4.10's and stock tires like I have, your topped out at about 75 in D. I always towed in OD once I got up to highway speeds, and if I had an incline coming up I would slow down slightly to 65 and put it into D. If I didn't slow down to 68 it would hit the limiter when the torque converter unlocked and shifted to 3rd.

Sorry to bring up an old thread.

I'm adding a temp gauge to my 4L80E and plan to tow like this. In overdrive on flat highway, shift out of OD in the hills. I have 4.10 gears and will be pulling a car hauler around about 65mph. So i'm good as long as the torque converter isn't unlocking/locking up and creating all that heat. At 65 MPH with D selected, my 5.7 is pretty spooled up.

 

[FellowTraveler]

I run my transmission cold w/o issues using Amsoil which actually protects at colder temps than other fluids do.

Take the 4L80e it requires min 28 deg f to fully function and the synthetic keeps it protected at much lower temps. On the high temp side I like 100 to 120 as measured in the pan while some will say this is not good because of moisture buildup from condensation I need to remind all that any condensation will steam off as the torque converter heats up the fluid to normally around 300 deg f as it exits trans and heads to the coolers. Trans fluid temps vary according to stall speed and torque multiplication of the converter.

Since I use EVANS waterless coolant my temps register slightly higher because the EVANS actually pulls more heat from the 6.5 diesel because there is no cavitation or steaming of water in EGW mixes so I was apprehensive about using the in radiator trans cooler but I had decided to to it and only a 15 deg f increase was recorded over using two stand alone large fin/plate coolers.

However, I would be remiss if I didn't point out that the radiator has many air gaps between it and the radiator support that should be sealed for proper airflow through the radiator and that little deflector/skid plate between the bumper and the radiator support should be there too or air flow through the radiator will stall at speed because of air rushing up under and forcing high pressure air up just behind the radiator shroud.

I my research I also found outer fender vents (styled to taste) are great addition to those vehicles equipped with inner fender vents which rely upon underhood hot air venting at the leading edge of the front door. The Range Rovers have these external vents at the trailing edge of their front fenders.

 

[billyg38120]

(1)
I have heard lots of conflicting stories about how to tow a trailer or haul loads with the 4L80E.

Some say just leave it in OD.

Some say run it in DD.

Some say Run OD till you hit a hill then down shift to DD then shift back up to OD.

Now i'm sure i'll hear a bunch more of these 3 claims again but i would like to know whats the Correct GM operating procedure for the opertation of the 4L80E ?

In a 4L80-E you can tow in OD. Only 4L60-E has the Tow in Drive restriction. Do you know why????? The EXPERTS here will know more than I.
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(2)
Now for Fluid type is this better off on Dino oil or run with a high end synthetic Fluid ?

How often should the fluid and filter be changed in these units ?

What type of fluid exchange would be best for these units ?

If your Trans has over 100k AND has NEVER had the fluid changed many trans shops and even the GM 700-R4 Tech guide states to not change it.
Change the fluid How Often? Depends on the use. Towing in HOT temps, every year. Driving in Cool temps (Canada) once a year Drain the fill.
Synthetic or Not in a 4L80/85-E. Inside GM we had to change the pressure tables with one brand of car that used the 4L80-E. Higher Pressure.
Dex3 or 6? Do you know what the diff is???? I use Dex 3, change the fluid, brake clean off all the internals with the pan off, allow the brake clean to dry, reinstall the filter and fill to the FULL HOT mark with ambient temp fluid. (Think about this. In 4th Gear with TCC on, all the clutches are filled. Even with the post 95 case there is still a small amount of oil in the pan. An extra 1/2 quart won't hurt it.)
Oil is cheap, metal and paper clutches are not.
Dex 6 is only Dex 3 with tighter specs for the additive package. Dex 3 is 1/3 the price. The gain, to me isn't worth the price when I cnhange it every 8 to 12k miles. USE NAME BRAND OIL.

.................................................. .................................................. .............
(3)
Now how about the cooling of these units ?
Do these Trans pan coolers work ? Not really. spend your money on a Long Ind stacked plate cooler. a 12" X 12" by 1.5" thick

The extra 1qt in volume with flow threw cooling tubes ? Put a deep pan with a LARGE COOLER in front of the A/C Condenser
or
The extra 3qts in volume with cooling fins ?

Pans with tubes??? Take a Thermocouple and place it in front of the trans pan to measure the temp of the air. Then take a flow meter or a string and place it under a stock pan. The air flow is small and the temp that will cool this tube set up is around 150 to 175 degrees. this is dependant on air flow and ambeint temp. OIt is not worth it. Put your money on a STACKED PLATE COOLER or a Oil over Water cooler. Why not the tube cooler that is cheaper? They are 50% less efficient.
I made my own cooler after I had talks with the GM Cooling men.
.................................................. .................................................. ...............
(4)
Now is the GM factory Cooler mounted by the Radiator the best way to go ?
or
Should and after market unit unit be used ?

some say get the GM cooler and bypass the Rad.

Some say get the GM cooler and run it inline with the Rad.

Some say after market next size bigger than your gross GVWR inline with Rad.

Some say next size bigger than you GVWR bypass the Rad.

Whats the best setup For the 4L80E ?
.................................................. .................................................. ................

 

[THEFERMANATOR]

(1)
I have heard lots of conflicting stories about how to tow a trailer or haul loads with the 4L80E.

Some say just leave it in OD.

Some say run it in DD.

Some say Run OD till you hit a hill then down shift to DD then shift back up to OD.

Now i'm sure i'll hear a bunch more of these 3 claims again but i would like to know whats the Correct GM operating procedure for the opertation of the 4L80E ?

In a 4L80-E you can tow in OD. Only 4L60-E has the Tow in Drive restriction. Do you know why????? The EXPERTS here will know more than I.

I agree with the 3rd about leave it in OD until the trans starts to hunt gears. THis is more so for the engine than trans protection IMHO. I will reach down and kick out OD even with my ALLISON when I'm coming up to a hill I know it won't hold in 5th. It doesn't change the fact that GM took the time to put a warning label in the door jamb telling owners of trucks equipped with a 4L80E trans NOT to tow in OD. I and many others don't agree with it and towed in OD anyways, but GM's stance was not to(or at least for 95 in which case my 95 still has the sticker in the door jamb).
.................................................. .................................................. ...........
(2)
Now for Fluid type is this better off on Dino oil or run with a high end synthetic Fluid ?

How often should the fluid and filter be changed in these units ?

What type of fluid exchange would be best for these units ?

If your Trans has over 100k AND has NEVER had the fluid changed many trans shops and even the GM 700-R4 Tech guide states to not change it.
Change the fluid How Often? Depends on the use. Towing in HOT temps, every year. Driving in Cool temps (Canada) once a year Drain the fill.
Synthetic or Not in a 4L80/85-E. Inside GM we had to change the pressure tables with one brand of car that used the 4L80-E. Higher Pressure.
Dex3 or 6? Do you know what the diff is???? I use Dex 3, change the fluid, brake clean off all the internals with the pan off, allow the brake clean to dry, reinstall the filter and fill to the FULL HOT mark with ambient temp fluid. (Think about this. In 4th Gear with TCC on, all the clutches are filled. Even with the post 95 case there is still a small amount of oil in the pan. An extra 1/2 quart won't hurt it.)
Oil is cheap, metal and paper clutches are not.
Dex 6 is only Dex 3 with tighter specs for the additive package. Dex 3 is 1/3 the price. The gain, to me isn't worth the price when I cnhange it every 8 to 12k miles. USE NAME BRAND OIL.
Um, I'm calling BS on your statement about DEX VI being DEX 3 with a tighter additive package. How can a FULL SYNTHETIC fluid be the same as a conventional mineral based oil? DEX VI is a FULL synthetic fluid of a LOWER viscosity than DEX 3 for longer drain intervals because it doesn't rely on an additive package to maintain it's lubrication and viscosity properties. I'm not a fluid expert, but even I know enough to know DEX VI is a COMPELTELY different fluid from DEX 3. As for when to change it, if it's never been done changing it coudl open up a can of worms. I myself believe in changing at least every 30K miles.
.................................................. .................................................. .............
(3)
Now how about the cooling of these units ?
Do these Trans pan coolers work ? Not really. spend your money on a Long Ind stacked plate cooler. a 12" X 12" by 1.5" thick

The extra 1qt in volume with flow threw cooling tubes ? Put a deep pan with a LARGE COOLER in front of the A/C Condenser
or
The extra 3qts in volume with cooling fins ?

Pans with tubes??? Take a Thermocouple and place it in front of the trans pan to measure the temp of the air. Then take a flow meter or a string and place it under a stock pan. The air flow is small and the temp that will cool this tube set up is around 150 to 175 degrees. this is dependant on air flow and ambeint temp. OIt is not worth it. Put your money on a STACKED PLATE COOLER or a Oil over Water cooler. Why not the tube cooler that is cheaper? They are 50% less efficient.
I made my own cooler after I had talks with the GM Cooling men.

Complete agreement here. The finned or tubed pans have proven little to no gain.
.................................................. .................................................. ...............
(4)
Now is the GM factory Cooler mounted by the Radiator the best way to go ?
or
Should and after market unit unit be used ?

some say get the GM cooler and bypass the Rad.

Some say get the GM cooler and run it inline with the Rad.

Some say after market next size bigger than your gross GVWR inline with Rad.

Some say next size bigger than you GVWR bypass the Rad.

Whats the best setup For the 4L80E ?
I DO feel the radiator should stay inline because at low speeds you get no cooling from a liquid to air cooler. At least GM was smart enough to use a design for the 6.5 trucks to maintain coolant flow across the trans cooler in the radiator.
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In red.