Transmission cooler: to by-pass the radiator or not to by-pass it

[Jayzero911]

I can't believe I just sat here and read 7 pages of this.... and would like to note I never did see real data from Drcoffee. I have yet to install a trany cooler but it is planed for the vary near future. I never considered the trany temps because I figured it would be cooler if anything (given the difference in size and cooling area) and that has never hurt a car that I have known of. At AAI I was always told HEAT was your number 1 enemy. While running too cool was not a concern the fear of a pink milkshake is. I know they are mostly caused by poor maintenance, but I have seen things fail for no logical reason. So even with 54k miles on my 3ed gen I want to install a cooler so there is no chance of mixing fluids. After reading peoples SG readings and seeing there is no real change in the temp ranges it is running in I have no worrys at all in doing this mod (in-line filter at the same time) I fail to see the problem with spending the $50-100 to keep a $800-2k part from being a paper wight.

However I am a little worried about drcoffee..... it seems anyone that disagrees with him or dose this mod is in a "cult" :shrug:

 

[Drcoffee]

...is in my radiator. After the gunk dries, it has a powder-like consistency. I am almost certain it is a rust or corrosion of some kind. I'll take a photo of it next time.

The stuff collects to my radiator cap. I'm glad the engine didn't overheat from Virginia to Montana.

Think "stop leak."

You may want to keep an eye on the cooling system and Head gasket for leaks. Someone put it in for a reason. I doubt it is rust.

 

[absalom]

I'm sitting here right now, having just read through this entire thread in one session, and I'm kind of in disbelief that I have a girlfriend and a job, and that I've actually lost my virginity

For those of you who actually posted hard data, especially Pikeman, thank you. I bought my rig with 131,000k and promptly added an external tranny cooler because I made an educated choice based on speaking to people who maintain and build vehicles for a living here in SoCal. Next up, I'm replacing my radiator with a Koyo. In my opinion, best of both worlds. I agree you should do your own research, but most people don't have access to trained experts, hence relying upon this forum for quality advice. I've been uniformly impressed with the advice I've received from various members on this forum, yet I've always sought a professional opinion to validate that advice. And more often than not, those professionals, ranging from Sonoran Steel to Outdoor Logic to my local garage, have agreed with info I gathered from here.

So I for one will keep using these forums. And I'll keep having confidence in my rig. Thanks to the genuine posters who actually give a damn about their fellow T4R owners!

You lost your virginity?? Lucky ... what was it like?

 

[jonwilly2]

maybe on a dodge or something. According to that by 11:00a today my transmission will not work cuz of the ambient temp in the parking lot

I got a trans cooler out of a ford excursion its 12x6 and works awesome I also got a oil cooler out of a chevy and a small fan out of a jeep keeping everything cool.

 

[the great him]

maybe on a dodge or something. According to that by 11:00a today my transmission will not work cuz of the ambient temp in the parking lot

I got a trans cooler out of a ford excursion its 12x6 and works awesome I also got a oil cooler out of a chevy and a small fan out of a jeep keeping everything cool.

that jeep fan is gonna break on you and stop working... just sayin

 

[Martinjmpr]

Real-world data from my recent trip:

Specifics: 1999 4runner SR5, 3.4, auto, 4x4, 146,000 miles (at the beginning of the trip.)

My B&M external cooler is installed bypassing the stock tranny cooler.

I was pulling a ~1200lb teardrop trailer with a ~80lb (estimated) tongue weight, from Denver to Grants Pass, OR, via I-80, US-30, I-84, US-26 and some state highways in Oregon.

Return trip was across CA to Reno, NV, then US 50 across Nevada and Utah to Grand Junction, CO and then back to Denver via I-70 (which includes 2 10,000'+ passes.)

I have a Scangauge II with the TFT (Transmission Fluid Temperature) set as one of my primary gauges (I got the SGII for that express purpose.)

Driving East to West across Wyoming with ambient temperatures ~80f into a 35-45mph headwind, I did sometimes get tranny temps as high as 200f. I had started driving with the OD on and quickly learned that if I took the OD off my tranny temp would immediately drop as much as 20 degrees f.

With OD off my temps rarely got above 190f. As soon as I turned off the interstate and was no longer heading into the wind, tranny temp dropped another 10 degrees.

Coming home I noticed much the same thing - I had the OD on when I was on flat ground or on a mild hill, on steep hills (both up and down) the OD was switched off and it cooled off the tranny by a noticeable degree

(side note: The owner's manual says you should switch the OD off when towing, but the manual says this is to increase the engine/tranny braking capability. AFAIK the manual says nothing about the use of OD heating up the tranny, which seems strange to me.)

Honestly it surprises me that the transmission temperature gauge isn't more common on vehicles. I know our 4runners have an idiot light but I don't know how hot the temp has to get before that comes on.

I'm embarrassed to say this, but a couple of times I let my temps creep to as high as 215, mostly it was because I was cruising along in OD and started going up a hill and forgot to switch off the OD. As soon as I noticed the temp being that high I would immediately switch off the OD and the temp always fell at least 15 degrees right away, and ultimately fell to below 190.

 

[Millerad1651]

bypassing the stock cooler for the win!

 

[1985taylor1925]

I have been working on developing what I call a "hamster cooling system", where I use highly trained and skilled hamsters to constantly drop ice cubes into my radiator, thus cooling my engine and tranny at the same time. However the hamsters tend to get distracted easily, or fall into my engine fan and get chopped up

 

[notarex]

However the hamsters tend to get distracted easily, or fall into my engine fan and get chopped up

Distracted hamsters are the #1 cause of "red and chunky milkshake". I recommend bypassing the hamsters immediately

 

[Drcoffee]

Real-world data from my recent trip:

Specifics: 1999 4runner SR5, 3.4, auto, 4x4, 146,000 miles (at the beginning of the trip.)

My B&M external cooler is installed bypassing the stock tranny cooler.


.

This really could have been an excellent opportunity to test both methods had you reconnected the radiator on the return trip. What I'd like to have seen is your temps when stuck in rush hour traffic while pulling the trailer. Under ideal circumstances: traveling at highway speeds, in 80 degree temps

We can all agree that the temps will range right where you saw them. Its not normal driving under ideal conditions that thrashes a transmission. Its those times when excessive heat/cold are a factor and the system is under considerable strain.

I have done this with other cars and the last one was a 99 corvette (ground breather) and the tranny would not stay below 200 unless the radiator was connected. And that was while moving above 30mph.

The radiator transmission cooler is a modulator. It adds heat when needed and removes it when its not needed.

If you look at the Lincoln Town Car, it only has an external cooler but it spans the entire width of the radiator and is about 6" vertically. Its designed to be between the AC condensor and Radiator. This way it won't get too cold or too hot and it benefits from the radiator fan. These seem like small differences but they are important to the flexibility a vehicle must have in all environments. And I am by no means saying it is perfect, but it's the way engineers have designed the cooling system.

Thanks for your input, albeit incomplete.

 

[Jayzero911]

Going to buy a Scangauge before installing a cooler just so I can see if I will need to install a fan in font of the cooler.

 

[Drcoffee]

Going to buy a Scangauge before installing a cooler just so I can see if I will need to install a fan in font of the cooler.

That would be a bad idea to install a pusher fan. They obscure the face of the cooler and they are only fractionally as efficient as a puller fan (<70% efficient as a puller).

If you want a better suggestion, search ebay for a used motorcycle cooling fan and space the cooler forward enough fit the fan behind it. Use a thermal inline switch connected to the battery routed through the accessory circuit to trigger it. I had a sweet litte setup on a twin turbo intercooler once where air flow was very restricted. It was way more reliable than an off the shelf cooling fan as all OEM items are and it worked like a charm. On my setup I had a boost switch kick it on with a direct connection to the battery. So anytime I entered boost, the fan kicked on and kept the temp down. Also, if you plan on a fan, you don't have to orient it in front of the radiator. You can put it horizontal and have the fan pull cool air down through it. It just depends on how creative you want to get.

Cheers

*It looks like a pusher setup but it actually pulled air up from below. The shround was a Lexan sheet cut and molded to seal against the intercooler. The fan came from a Yamaha FZR road bike and was super quiet and powerful. There was one on each side of the car.

 

[Drcoffee]

I finally got around to installing my B&M 70264 cooler last night. Actually went smoothly which is rarely the case for me.

First job was to remove the grill and the driver's side horn. I put a "S" bend in the horn bracket to clear the cooler. About 1/2" jog in the bracket clears the cooler nicely and it stays in the stock position. Then a good blast of compressed air into the AC condensor to clean out any crud from years of driving. Here is the mounted cooler fastened into place. In order to get the best affect from the engine fan I mounted it up flush to the condensor. There are foam pads between the two. Its important to note that with the engine running you can feel the air being drawn in through the cooler as you want the cooler to work even if you are standing in rush hour traffic.

If you look at the ports on the cooler they are directed right by the radiator mounts which will wear through the hose in time. So I sleeved the hose with small radiator hose to cover the 3/8" cooling hose both top and bottom. They are plumbed through the hole in the body on the driver's side because it will go right into the radiator exit port with the shortest run and then back out to the in-line filter before heading to the transmission. The supplied hose with the cooler was long enough for both connections.

From underneath you can see the radiator port rotated to the 11 o'clock position. I had to bend the pipe out about a 1/4" to clear the fan shroud. The other line connects to the Magnefine in-line filter before returning the fluid to the transmission. These filters are designed for 30,000 mile service life but if you forget to replace it, it has an internal valve to bypass the filter if the filter gets clogged.

And finally the install is complete.

 

[240m3srt]

I finally got around to installing my B&M 70264 cooler last night. Actually went smoothly which is rarely the case for me.

First job was to remove the grill and the driver's side horn. I put a "S" bend in the horn bracket to clear the cooler. About 1/2" jog in the bracket clears the cooler nicely and it stays in the stock position. Then a good blast of compressed air into the AC condensor to clean out any crud from years of driving. Here is the mounted cooler fastened into place. In order to get the best affect from the engine fan I mounted it up flush to the condensor. There are foam pads between the two. Its important to note that with the engine running you can feel the air being drawn in through the cooler as you want the cooler to work even if you are standing in rush hour traffic.

If you look at the ports on the cooler they are directed right by the radiator mounts which will wear through the hose in time. So I sleeved the hose with small radiator hose to cover the 3/8" cooling hose both top and bottom. They are plumbed through the hole in the body on the driver's side because it will go right into the radiator exit port with the shortest run and then back out to the in-line filter before heading to the transmission. The supplied hose with the cooler was long enough for both connections.

From underneath you can see the radiator port rotated to the 11 o'clock position. I had to bend the pipe out about a 1/4" to clear the fan shroud. The other line connects to the Magnefine in-line filter before returning the fluid to the transmission. These filters are designed for 30,000 mile service life but if you forget to replace it, it has an internal valve to bypass the filter if the filter gets clogged.

And finally the install is complete.

So i was searching for radiator part numbers when somehow this thread came up. 1 hour later i stumble my way to the end, to find to my dismay...that after all that you finally gave in and installed the external cooler...and the evil cult of 5-6 didnt notice? Time to trade in that left nut:hatsoff::beer:

 

[Drcoffee]

So i was searching for radiator part numbers when somehow this thread came up. 1 hour later i stumble my way to the end, to find to my dismay...that after all that you finally gave in and installed the external cooler...and the evil cult of 5-6 didnt notice? Time to trade in that left nut:hatsoff::beer:

Not so my observant little friend. I'm all for external coolers. I have them on all my vehicles. My discussion was based on bypassing the radiator. I did not.

My cooler was installed in series with the radiator as I profess to be the better solution. Allow the radiator to modulate the transmission temp and then using an external cooler, bring the operating temp back down by 20*.

You may want to re-read the last 9 pages.

LOL



Like a phoenix, the thread rises from the fire:cheers:

 

[quicksilvr]

I want to put a little more data into this thread, since it's still alive.

Having my radiator bypassed for about 4 months now (on my current 4Runner), I have temperature numbers for several months worth of stock cooler, and several months worth of bypassed cooling with the 70264.

The factory cooler does maintain a smaller window of temperature range. For example, on a day like today (a beautiful 65 degree day), the factory cooler would keep the transmission temperature between 148 and 160 during normal driving. That's a 12 degree window, give or take a degree or two.

The aftermarket cooler, bypassing the radiator maintains transmission temps of about 140-162. That's a 22 degree window.


So yes, temperature modulation is "better" with the radiator. I cannot deny it. But guess what? Myself AND my transmission are totally ok with that slightly larger temperature range. The transmission doesn't care one bit if the temp varies through a range like that any more than if it stayed at exactly 158 degrees all day long and never changed.

 

[240m3srt]

Good info Quicksilvr.

I have the Trucool 4454, its basically the same size as the B&M 70264(B&M is a tad bigger). I was thinking of going to the Hayden 1679 its about 3" larger than the previous 2 and pretty inexpensive. Its a big unit made for Class A motor homes.

Transmission Part by Bulk Part Hayden Transaver Plus Hayden Transaver Plus, extra heavy duty & standard installation kit

Anyone running this? From what i can tell its the same one Level 10 handed Gadget if youve ever checked his site out. He claims 11x17 but i think he meant to type 11x11. Transmission Modifications (bottom of page)

Aww heck 300 post count, time for a supercharger ROFL:trophy:

 

[Drcoffee]

I want to put a little more data into this thread, since it's still alive.

Having my radiator bypassed for about 4 months now (on my current 4Runner), I have temperature numbers for several months worth of stock cooler, and several months worth of bypassed cooling with the 70264.

The factory cooler does maintain a smaller window of temperature range. For example, on a day like today (a beautiful 65 degree day), the factory cooler would keep the transmission temperature between 148 and 160 during normal driving. That's a 12 degree window, give or take a degree or two.

The aftermarket cooler, bypassing the radiator maintains transmission temps of about 140-162. That's a 22 degree window.


So yes, temperature modulation is "better" with the radiator. I cannot deny it. But guess what? Myself AND my transmission are totally ok with that slightly larger temperature range. The transmission doesn't care one bit if the temp varies through a range like that any more than if it stayed at exactly 158 degrees all day long and never changed.

Quick,

No doubt you have reasonable numbers when using your truck in a reasonable way. The discussion was focused on the "lack of flexibility" in a bypassed system. You need to post temps from extreme conditions such as days where the high temp is -10* or 110*. Or 4 wheeling for a good afternoon where air flow is poor and stress to the transmission is high. Then we can have an honest talk about the best solution for the average truck. But if you just want to talk about running to the grocery store on 65* day, you probably don't even need a cooler period.

 

[TX4Running]

Radiator design

I have some black particles in the bottom of my coolant reservoir. Nothing is floating so I know it's not oil. Any ideas? Possibly a deteriorating hose?

Also, my radiator appears to have 2 exchangers, one in front of the other? Is this normal on a 2001 SR5 4WD? All pics I've seen show just the single exchanger. I was looking at installing an external cooler and wanted to make sure I had enough room. Thanks.

 

[Drcoffee]

I have some black particles in the bottom of my coolant reservoir. Nothing is floating so I know it's not oil. Any ideas? Possibly a deteriorating hose?

Also, my radiator appears to have 2 exchangers, one in front of the other? Is this normal on a 2001 SR5 4WD? All pics I've seen show just the single exchanger. I was looking at installing an external cooler and wanted to make sure I had enough room. Thanks.

The front one is your AC and rear one is the radiator. There's enough room for the cooler. Look for one with 1.5" thick core. The b&m 70264 is a great choice. Mine, installed in series with the radiator has been keeping my tranny temps below 160, typically it runs between 135 & 155. In this cool weather it takes about 10 miles to get up to 130*.

The crud in the reservoir is probably just dirt. You can remove it and clean it out but if the fluid is not cloudy, why bother.