Time to Get Serious With 4L60e/4L65e Cooling...

[Curt]

I had my tranny shop install a Tru-Cooler Part# 20-4590 28k BTU which is 11x11x1. My temps went from over 200s down to 165s to 190s..

I tow roughly 7k lbs. I'm very happy tower now!!! lol

That's great to hear! I honestly was thinking of going that route, but knowing my current set-up I'd be afraid of the cooler not being able to keep up. Same goes for the M7B, I know it cools like 20*F-30*F but my temp being at 250*F+ on a 100*F day probably won't be too much help.

Yea no use in spending money agian and upgrading the cooling will be beneficial either way you go.

Precisely. I'm going to make due with what I got. All I'm really looking for is a truck I can occasionally hook a trailer up to and not have to keep my eyes glued on the trans temp gauge. We got a different vehicle as our dedicated tow pig, but I enjoy taking the suburban once in a while.

 

[df2x4]

Even as a 4L60E hater I would agree that a Tru-Cool 40K is probably one of the best possible things you could do to help keep one alive. I considered using a 40K when I did my 4L80E swap just for extra insurance but I didn't want to mess with relocating horns or anything to squeeze it in. I went with the M7B and so far so good, although I haven't checked my temps at all since the swap. I hauled a bunch of stuff across the state with that truck earlier this month and it never showed any signs of heating up. Also running 3.42 gears.

Tru-Cool is good stuff. Especially for the price.

 

[L31MaxExpress]

That's great to hear! I honestly was thinking of going that route, but knowing my current set-up I'd be afraid of the cooler not being able to keep up. Same goes for the M7B, I know it cools like 20*F-30*F but my temp being at 250*F+ on a 100*F day probably won't be too much help.

What is your coolant temperature when the trans is overheating? The cooler in the radiator does a large chunk of the actual trans cooling. If you have a weak fan clutch or partially stuck thermosat it can overheat the cooling system which will also drove trans temps up. That being said if the stock cooling system is not keeping the trans temps in check you gave a trans problem. I suspect your converter is not locking up.

 

[LVJJJ]

I just installed an 8"x11" B&M 70266 cooler on my '94 GMC k1500 and boy does it work. Had a bung placed in the oil pan and hookd up a trans temp gage (AutoMeter). We just got back from a 600 mile trip towing a 5,000 lb travel trailer to eastern Washington where it was over 100 degrees much of the time. On "normal" days with temps around 80, the trans temp never went over 165. One day it was 103 or more on an up and down blue highway, and the temp never went over 180. Clutch fan came on alot to cool the engine but it never overheated. Also ran AC all day too, the 383 stroker doesn't care if its on or not. So, these bigger trans coolers are really a necessity to keep the 4L60e's cool. Had never heard of the Truecool coolers so went with B&M, glad I did, worked great.

 

[jaywestfall]

Even as a 4L60E hater I would agree that a Tru-Cool 40K is probably one of the best possible things you could do to help keep one alive. I considered using a 40K when I did my 4L80E swap just for extra insurance but I didn't want to mess with relocating horns or anything to squeeze it in. I went with the M7B and so far so good, although I haven't checked my temps at all since the swap. I hauled a bunch of stuff across the state with that truck earlier this month and it never showed any signs of heating up. Also running 3.42 gears.

Tru-Cool is good stuff. Especially for the price.

Good to know. I don't tow, but I'm keeping my 3.42 gearing, too.

 

[alpinecrick]

I don't think the TruCool MAX coolers are LPD. Looking at the website they offer the same cooler with or without "cold weather bypass". Different part numbers for the kit with the bypass, but the same cooler. If the cooler was LPD there would be no need for a bypass. TruCool's literature is a bit misleading, me thinks......

Also, the MAX coolers are plate & fin as I mentioned. Which means it has the thin fins in between the tubes in the same manner as a radiator or condenser. The only way to fit the MAX coolers would be to install them in front of the little vertical strut that houses the latch and horn. That would put the cooler almost tight behind the grill, an even easier target for road debris, bumble bees the size of B-52's, and rocks. And the fins will fill up with road gunk quicker than a stacked plate design.

I have the grill off my 97 currently, and did some measuring for the H7B (11 x 11 and 1 1/2 thick) and the largest stacked plate cooler Tru Cool offers) and for the LPD 4739 (8 1/2 x 22 and 1 1/4 thick).

It looks like the H7B would have to be moved over towards the passenger side a couple inches and maybe moved down an inch, but I think the lines have enough flex that they wouldn't have to be modified.

The 4731 would have to modify the one line, the horn looks like it can easily be moved up.

As far as installation either one is fairly simple.

The other option is a pusher efan on the cooler.

I've been having this debate with myself over this for some time now.....

 

[TheAutumnWind]

The TruCool 40K GVW cooler is NOT a LPD cooler. For those who live above or below the equator LPD coolers are a good thing for the trans when it's cold outside (and I don't mean only when it's 20 below).

Edit to add:
I have one of these I picked up really cheap in the event I do use something like the 40K cooler. It does the same thing as a LPD:
https://derale.com/product-footer/fluid-coolers/thermostats-1/fluid-control-thermostats/13011-detail

2nd Edit:
I bet half the condensers on trucks with 50k or more on them are partially filled with debris/dirt in the fins.........
Pull the top and bottom shrouds, fan and clutch, radiator brackets, shine a flashlight from the backside of the condenser and see how plugged the condenser is.

Thats why I hit mine with degreaser and a pressure washer once a year or so.

 

[Curt]

Even as a 4L60E hater I would agree that a Tru-Cool 40K is probably one of the best possible things you could do to help keep one alive. I considered using a 40K when I did my 4L80E swap just for extra insurance but I didn't want to mess with relocating horns or anything to squeeze it in. I went with the M7B and so far so good, although I haven't checked my temps at all since the swap. I hauled a bunch of stuff across the state with that truck earlier this month and it never showed any signs of heating up. Also running 3.42 gears.

Tru-Cool is good stuff. Especially for the price.

Precisely. Heat is the killer of transmissions. I don't think the stock 5.7L vortec power is the reason the transmission likes to die haha. As far as trans temp gauge goes, I would highly recommend one. If I didn't have the gauge I wouldn't have noticed my trans being at 250F+ for a prolonged period of time. Seriously, no signs of the trans overheating. Right at the very end of my trip (last 5 minutes) it started slipping from the heat. Without the gauge (and last 5 minutes of my drive), I would've thought the transmission was happy the whole way there.

What is your coolant temperature when the trans is overheating? The cooler in the radiator does a large chunk of the actual trans cooling. If you have a weak fan clutch or partially stuck thermosat it can overheat the cooling system which will also drove trans temps up. That being said if the stock cooling system is not keeping the trans temps in check you gave a trans problem. I suspect your converter is not locking up.

Coolant temp was at a happy 195F-ish the whole way. No issues there, coolant temp barely rose on the hills either, probably the hottest it got was 200F. I don't think my issue is related to a problem with my engine cooling system. My transmission temps for that trip were as followed:

3rd: Used for climbing hills and slower flat-ground towing. Temp ranged from 180F-250F+
4th no TC lockup: Rarely used, made sure to keep truck in 3rd whenever possible. 210F-250F+
4th TC lockup: Used on flat-ground and highway. 180F-200F

The 4731 would have to modify the one line, the horn looks like it can easily be moved up.

As far as installation either one is fairly simple.

The other option is a pusher efan on the cooler.

I've been having this debate with myself over this for some time now.....

Once all the parts come in and I get some time between my classes, I'll make sure to take detailed notes and make a list of parts needed. Most likely will post a how-to guide somewhere in this thread, or maybe make a different one. Hopefully that'll help sway you one way or the other

Thats why I hit mine with degreaser and a pressure washer once a year or so.

That's a great idea. I'm going to steal that one from you once I tackle the cooler install haha. Which degreaser do you use?

 

[alpinecrick]

Thats why I hit mine with degreaser and a pressure washer once a year or so.

35+ years ago I had a buddy with a 90 K1500--who had zero mechanical knowledge--routinely stick the car wash wand in his grill and wash all the "stuff" behind the grill. He couldn't figure out why his truck was overheating--he had flattened practically every fin on the condenser.......

As I mentioned earlier in the thread, I bet most of the condensers on these trucks are partially plugged with debris and lots of flattened fins from various impacts. I just recently, meticulously and anally, straightened fins and pulled as many of the small stones out between the fins on the condensers of my 96 G1500 and K1500 with a pick, then pulled the radiators back and with my 90 degree water and air wands cleaned the condensers from the backside. Then several coats of foaming condenser cleaner, and more washing. LOTS of gunk came out. Attempting to wash condensers/radiators from the front side pushes a lot of the gunk deeper into the fins.

 

[alpinecrick]

Once all the parts come in and I get some time between my classes, I'll make sure to take detailed notes and make a list of parts needed. Most likely will post a how-to guide somewhere in this thread, or maybe make a different one. Hopefully that'll help sway you one way or the other

If you get the MAX cooler make sure you buy the one with the external bypass, because I don't think those coolers have the internal LPD despite TruCool's advertising to the contrary.......