would you add an additional transmission cooler?

[ABN_CBT_ENGR]

Originally Posted by MrTruckDriver


correct. I was pulling about 4500 pounds going up hill at about 30 mph.


In a one off, that's not too bad but if your routine driving requires this on a cyclic basis, it would warrant probably additional cooling.

First thing I would do is see if there is a fan configuration capable of pulling more CFM over the current configuration ( easiest way to add a little more exchange)

If it takes another exchanger then its a question of series or parallel but that cant be answered accurately unless you define the overtemp in terms of

are you adding additional heat at the source ( putting more energy into the fluid with a higher discharge temp)

or

just need a little more soak time for the exchange

 

[4WD]

If counting on upgrades to electric fans … he'll need to make sure the cooler is spaced very close to the AC condenser/radiator or the airflow will bypass the cooler.

This was proven by two guys with identical vehicles who got way different results with the same aftermarket cooler.
Can of disco smoke found the issue.
This also facilitated faster cool downs in traffic or when off-roading slow in soft terrain … (loaded) …

 

[ABN_CBT_ENGR]

Originally Posted by 4WD
If counting on upgrades to electric fans … he'll need to make sure the cooler is spaced very close to the AC condenser/radiator or the airflow will bypass the cooler.

This was proven by two guys with identical vehicles who got way different results with the same aftermarket cooler.
Can of disco smoke found the issue.
This also facilitated faster cool downs in traffic or when off-roading slow in soft terrain … (loaded) …


Oh yeah,Without saying- must have volume and velocity ( along with a flow path) and depending on if its a push or pull ( forced or induced draft)- the location relative to air temp becomes a factor. ( harder to cool with hot air)

 

[MrTruckDriver]

hmmm not sure if im understanding correctly.
i have the fan on the cooler in a push configuration.
my set up goes front grill, fan with shroud, cooler then a pretty big space between the cooler and radiator.

when the cooler fan is running i can put my hand behind it and it feels like hot air from a hairdryer.

i think the fan is 500 cfm,

 

[ABN_CBT_ENGR]

Originally Posted by MrTruckDriver
hmmm not sure if im understanding correctly.
i have the fan on the cooler in a push configuration.
my set up goes front grill, fan with shroud, cooler then a pretty big space between the cooler and radiator.

when the cooler fan is running i can put my hand behind it and it feels like hot air from a hairdryer.

i think the fan is 500 cfm,


That sounds like the usual systems I have seen.

The "answer" ( what way and how much additional exchange you could use based on your driving and towing scenario) is going to be determined by what you have versus what you are willing to do.

Heat exchange is a very finite and well understood science and there are many different ways to go about it but they all have to fit the situation.

In your case

you have 2 different convections here

1- Mechanical heat to fluid ( done in the transmission and a result of the work and relative to fluid volume, flow etc)

2- Fluid heat to surface area ( removed by air flow and the effectiveness is generally the total area and the volume of air at a given temp)

So to get additional exchange (cooling)- you need to start changing those properties in relation to each other ( modify the current system)

OR

Add additional exchange capacity

That decision is based on exactly how much additional heat is being put into the fluid and how much time is required to remove it by various methods.

(all this is assuming the transmission has the mechanical ability and integrity to handle the load in the first place- no cooling amount will negate a mechanical overload)

Did that help or make it worse?

 

[MrTruckDriver]

it helped. my truck is rated to pull 5400 lbs. even though im staying within spec i think im pushing it too hard. even if i add a bigger cooler i still have a transfer case, little 8.6 diff and no engine oil cooler.
I bought a slightly bigger travel trailer then i intended.

my current plan is to stay on generally flat areas with my current set up. I'll use my trans temp as the limit for the whole truck.

it's looking like im after a lighter trailer or a 3/4 ton

 

[R1jake]

I'm thinking I need to a a cooler as well, 94 e150 5.8l E4od with no transmission cooler besides the one going through the radiator. I pull a 95 hi point fiberglass enclosed trailer with 2 sportbikes a few times a year. The weight of the trailer shows 700lbs and the bikes add another 800 I'd say so I'm definitely under 2000lbs. But a lot of the info I have found says a conversion van alone should have a seperate transmission cooler just because of the extra weight of the conversion package. I'm struggling with not wanting anything in front of my condenser and radiator so considering another place with a fan mounted on it that can be ran manually as well as automatically kicking on at a certain temperature.

 

[MrTruckDriver]

Originally Posted by R1jake
I'm thinking I need to a a cooler as well, 94 e150 5.8l E4od with no transmission cooler besides the one going through the radiator. I pull a 95 hi point fiberglass enclosed trailer with 2 sportbikes a few times a year. The weight of the trailer shows 700lbs and the bikes add another 800 I'd say so I'm definitely under 2000lbs. But a lot of the info I have found says a conversion van alone should have a seperate transmission cooler just because of the extra weight of the conversion package. I'm struggling with not wanting anything in front of my condenser and radiator so considering another place with a fan mounted on it that can be ran manually as well as automatically kicking on at a certain temperature.


ive installed temp gauges on those transmissions before and its a pretty simple. and its nice to see what's going on. i personally like having the cooler up front as its easier to plumb and gets fresh air. that said i don't know how much room yours has.
in my experience when your buying a cooler get the big one.

 

[supton]

If the ATF goes through the radiator, doesn't that mean it wants to be 190F in the unloaded case? The trans in my truck is completely different, but, mine will get up to 190 in short order on the highway, and seems perfectly happy to sit there. And isn't known for short lifespans despite this. Did you state what the non-towing temperature was, on a long highway drive, and did I miss that?

The 4.8 likes to spin, which is good here, because once above the 2k or similar stall speed, slippage should be limited. Slippage generates heat. By keeping engine rpm up ATF temps should stay low(er). It'll go up due to the pump, and the extra heat in the radiator, but by watching the tach I'd think you could keep heat generation low.

I like the idea of an engine oil cooler, but didn't this truck already have one? Or was that only on the trucks with the tow package?

 

[MrTruckDriver]

im not sure if it has the tow package. it came stock with a little trans cooler as well as a power steering oil cooler. no engine oil cooler though. with my current set up ive never gotten it up to 190 running empty, even pulling my trailer on the highway temps would be in the 160s and hit 180 while climbing hills. when i made it hit 190 i wash pushing it. low speed on a 10 percent grade for about 15 min.

its probably outdated information but ive read keep an automatic transmission under 180 if you want it to last.

 

[MrTruckDriver]

i should probably add im not a fan of revving engines and dont let mine get much over 3000 rpm. I'm probably lugging the particular engine....

 

[spasm3]

Originally Posted by MrTruckDriver
i should probably add im not a fan of revving engines and dont let mine get much over 3000 rpm. I'm probably lugging the particular engine....


Better to rev than lug, lugging kills bearings.

 

[MrTruckDriver]

i blame the shift pints though i do back off the gas when it downshifts. sounds like a 2 stroke at 3500 rpm

 

[supton]

Yeah, I've been hearing that you need to keep it under 180F for it to last--yet some of the transmissions died if you looked at them funny. Others would go 200k on original fluid with towing. Reality was somewhere between I think. What year is your truck? You may have the updated 4L65, which has some more robust parts in it. I *think* if you look in the glove box you may find a listing of all the RPO's, three digit codes designating what options you have; I have no idea what is the trailer towing package but maybe you can look up what the codes you have mean. I took a quick look and Z82 is the tow package for at least a few years: one poster indicated that his 2500 didn't have Z82 yet had all the towing parts as part of the cold weather package... so it's possible that the engine oil cooler may show up under more than one RPO.

10% grade for 15 minutes? Even at 30mph that was going up hill for 7.5 miles and gaining some 4,000 feet in elevation.

 

[supton]

Originally Posted by MrTruckDriver
i blame the shift pints though i do back off the gas when it downshifts. sounds like a 2 stroke at 3500 rpm

That's when that 4.8L should be pulling hard! I'd wind it out. As it is, with but 4 speeds you're almost guaranteed to never be at the right RPM.

I'm not sure you can lug this engine. The TC is apt to unlock and prevent it from ever truly lugging, if not actually downshift for the same reason.

 

[R1jake]

If 190 was the highest you have seen while pushing it up a long grade your actually in the ideal range being you stated normally your seeing 160/180 I believe you said. After getting up the grade did the temp drop back to the norm 160/180s? If so it's working like it should.

 

[R1jake]

Originally Posted by MrTruckDriver
Originally Posted by R1jake
I'm thinking I need to a a cooler as well, 94 e150 5.8l E4od with no transmission cooler besides the one going through the radiator. I pull a 95 hi point fiberglass enclosed trailer with 2 sportbikes a few times a year. The weight of the trailer shows 700lbs and the bikes add another 800 I'd say so I'm definitely under 2000lbs. But a lot of the info I have found says a conversion van alone should have a seperate transmission cooler just because of the extra weight of the conversion package. I'm struggling with not wanting anything in front of my condenser and radiator so considering another place with a fan mounted on it that can be ran manually as well as automatically kicking on at a certain temperature.


ive installed temp gauges on those transmissions before and its a pretty simple. and its nice to see what's going on. i personally like having the cooler up front as its easier to plumb and gets fresh air. that said i don't know how much room yours has.
in my experience when your buying a cooler get the big one.




Well my other concern is when crossing the mountains specially deals gap AKA the dragon I drive 12/15 miles of up down corner after corner keeping it in second gear most of the time so it's not constantly shifting. This is where I would want a separate cooler with its own fan and where I would like to be able to turn it on manually for this particular 15 miles of [censored] in a van with a trailer loaded with bikes.

 

[MrTruckDriver]

Originally Posted by supton
Yeah, I've been hearing that you need to keep it under 180F for it to last--yet some of the transmissions died if you looked at them funny. Others would go 200k on original fluid with towing. Reality was somewhere between I think. What year is your truck? You may have the updated 4L65, which has some more robust parts in it. I *think* if you look in the glove box you may find a listing of all the RPO's, three digit codes designating what options you have; I have no idea what is the trailer towing package but maybe you can look up what the codes you have mean. I took a quick look and Z82 is the tow package for at least a few years: one poster indicated that his 2500 didn't have Z82 yet had all the towing parts as part of the cold weather package... so it's possible that the engine oil cooler may show up under more than one RPO.

10% grade for 15 minutes? Even at 30mph that was going up hill for 7.5 miles and gaining some 4,000 feet in elevation.


it looks like the 4l65 was paired with the 60L vortec only.

i could have my specs wrong on the hill. it was heading up toward a ski hill though, i drove up it to see if the truck could maintain 180 i chickened out at 190. im not sure what the deal breaker temp for the trans and dexron vi is.

 

[MrTruckDriver]

Originally Posted by R1jake
Originally Posted by MrTruckDriver
Originally Posted by R1jake
I'm thinking I need to a a cooler as well, 94 e150 5.8l E4od with no transmission cooler besides the one going through the radiator. I pull a 95 hi point fiberglass enclosed trailer with 2 sportbikes a few times a year. The weight of the trailer shows 700lbs and the bikes add another 800 I'd say so I'm definitely under 2000lbs. But a lot of the info I have found says a conversion van alone should have a seperate transmission cooler just because of the extra weight of the conversion package. I'm struggling with not wanting anything in front of my condenser and radiator so considering another place with a fan mounted on it that can be ran manually as well as automatically kicking on at a certain temperature.


ive installed temp gauges on those transmissions before and its a pretty simple. and its nice to see what's going on. i personally like having the cooler up front as its easier to plumb and gets fresh air. that said i don't know how much room yours has.
in my experience when your buying a cooler get the big one.




Well my other concern is when crossing the mountains specially deals gap AKA the dragon I drive 12/15 miles of up down corner after corner keeping it in second gear most of the time so it's not constantly shifting. This is where I would want a separate cooler with its own fan and where I would like to be able to turn it on manually for this particular 15 miles of [censored] in a van with a trailer loaded with bikes.


my cooler has a fan and i still mounted it up front.
i think as long as you mount it where it can get fresh air you're good to go. just make sure it's location won't subject it to things like mud and rocks.
my cooler came with a thermostat but i never installed it. i just have a toggle switch on the dash and turn in on when i see the temps climb.

 

[MrTruckDriver]

Originally Posted by R1jake
If 190 was the highest you have seen while pushing it up a long grade your actually in the ideal range being you stated normally your seeing 160/180 I believe you said. After getting up the grade did the temp drop back to the norm 160/180s? If so it's working like it should.


okay that makes me feel better. in the summer the ambient temp is about 100F. I will take the trailer for another test run and see how the temps look.