Thanks, that's good to know. Did they use a cooler with some kind of bypass for cold ATF?

 

That I am not sure of,Usually if there was a trans temp light issue,they wanted to check to make sure fluid could flow,ie cooler not clogged,also no debris in fins causing cooling problems,along with the usuall fluid overfilled..There was never a concern that the fluid would get too cold as I can recall,in any service manual/suppliment TSB procedure.I do remember seeing some of the coolers branded as Toyota/Hayden...

It is possible they used bypass trans. coolers on the cold weather spec landcruisers in canada and ROW vehicals,they would also get block and battery heaters,and dual batteries on the diesels..also sprayers for the front headlights(kinda neat).

 

OK, finally got mine installed (along with my timing belt and water pump) and have bypassed the radiator completely. I went with the mt_goat special and picked up the Tru-Cool 4454 from bulkpart.com. Comes with everything you need (cooler, hose, and mounting hardware). I did have to go get some extra transmission hose, though, as I needed more than the kit came with. I also flushed the exchanger in the radiator (you never know) and ran a hose from end-to-end to close it off. I'll probably go w/an aftermarket radiator that deletes the tranny cooler altogether; but for the short term this will do. I'll also be getting a temp gauge.

 

Thanks 97ltd4x4, Goat, and dgz, for the helpful responses.

I'm planning the exact same project as dgz32. I think I'm going to install a a temp gauge also. Not because I care that much about tranny temp(I don't tow that much), but because I figured that if I'm going to undermine the OE system, I better make sure my "fix" is working well.

 

Looks great

 

i installed a B&M Super Cooler Transmission Cooler, Part # 70264 on my 4runner last year. i didn't totally bypass my radiator trans cooler (high on the list of to-dos!). i haven't had any trouble with it, it came with LOTS of hardware for installation and mounting, and i got it since it had the added bypass that some of the others did not. keeps things cool in the summer, but after reading all the posts in this thread i am now a little concerned about overcooling in the winter now that our lows for the next week are projected to be in the negatives and highs in the single digits.

but, all i can say is that i've had good luck with the B&M cooler thus far.

 

While I am waiting on my cooler to arrive I decided to purchase a aftermarket rad. It was 200 bucks and it should eliminate the cooler issue trouble. I will still install the cooler but I have not decided if I will bypass or not. If I use the cooler in the new rad it should be trouble free for years. The new rad is aluminum core with plastic tanks the same as oem. The more I thought about it, if the trouble area is the rad it may be the best decision to replace the rad as a 10 year maintence item.

 

More power to ya! And I agree, for the most part. However, after seeing all of these threads...even with a brand new radiator (w/internal exchanger) I would still be concerned knowing that it could happen due to the design of the thing. Brand new parts fail all of the time, for me it just isn't worth the risk.

IMO, if your radiator is otherwise OK, replacing the internal exchanger with a $50 cooler is a good option - provided that it cools adequately, of course. I believe this to the point that I've installed one bypassing a known good internal exchanger.

That said, I've got my temp gauge and will be installing it this weekend so I can monitor things next week when we're driving all over creation.

 

Damn it, it maybe time for an upgrade. Would the TRD cooler be enough to cool if i were to bypass the factory cooler? Summer time i dont have an issue with temps since in city traffic it will reach 175-180 with both coolers. If i were to bypass would the temps be higher? I know i would benefit from this in the winter since the tranny temps barley reach 100-120.

 

I think the TRD cooler would be fine, except for the lack of a built-in bypass for cold temps (maybe in Texas that's not a concern) I doubt your summer temps would go up as long as your cooler is in front of a fan.

 

I live in northern MN and just had a tranny flush at the dealership, 50 dollar off coupon, and asked them if the had seen anything like this happen up here and they said they have not seen one come in. Maybe its due to the warmer temps causing an increase in acidity and consequential caustic effect that they are rupturing. Regardless, I was thinking about doing this to my '96 4runner but am slightly concerned with the overcooling effect considering this morning when I woke up it was -25 F with a windchill of -50 F and its not even the coldest month up here yet. Going with the set up mentioned earlier:

# 4589 Tru-Cool LPD
# 708-4739 Remote external thermal bypass

does anyone have any advice on this decision or with thermal bypass should I be alright?

Also, when I was looking at my radiator today it appears like there is two radiators already one smaller about 1/2 the size of the main one, I'll try and get a pic later, no flash on my camera, anyone know anything about this?

 

Sounds like a good plan, here's a pic of that thermo bypass BTW, looks good:
http://www.bulkpart.com/Merchant2/me..._Code=708-4739

 

If your transmission oil is running too "cold", here is what will probably happen based on my experience with large truck automatic transmissions. When you start your truck in the morning-and immediately go into "drive" (bad, but I see it all the time), your truck won't move or move slowly as the oil is making its way into the converter. When you do start moving, it will stick in 1st and second and shift hard. It may or may not go into 4th gear as the pressures will be really high inside the tranny.

If you let it warm up in the garage or outside for 5-10 minutes, you should be fine. ATF fluid is quite thin. If you are worried, by some ATF and pour it into a cup before your truck starts up. If it flows, so will the stuff in your tranny.

I may get flamed, but that is pretty much the basics. If you are really worried,......you are a Toyota 4runner owner.

 

Okay, I know

Here's a tail from my latest 4Runner maintenance adventure:

I took Mt Goat and 97ltd4x4's excellent advice and ordered at Tru Cool #4454 from Matko. The installation was going well last night until I get underneath the truck to re-route the lines.

I find that my OEM radiator has a slow coolant leak!

So, given that I'm about to depart on a 3000 mile road trip in 4 days, I'm debating putting in a whole new radiator. I called the local Toyota dealer and they quoted me $373.55 installed for an aftermarket cooler. This seems very reasonable and I think I'm going to go for it.

Here's the question: would you have them plumb the aftermarket tranny cooler (TruCool 4454) inline with the aftermarket radiator tranny cooler pipe, or would you have them bypass it? I'm guessing that the aftermarket radiators would not have the same issue as the OEM 4Runner radiators, but I'm not positive.

Keep up the great thread!

 

I bypassed my aftermarket radiator, but I don't remember anyone having a problem with one. That would be really weird if the cheap "made in China" radiators were actually better quality than the OEM Toyota radiators, but who knows

Make sure they use distilled water to mix with the coolant for the refill. I've had dealers use tap water before (you might have to bring your own water)

 

Another successful cooler bypass. It turns out that my factory radiator is still fine, no leaks.

I got the Tru-Cool 4454 as Goat suggested. No issues at all with the placement:





I ran the hoses through the hole for AC lines. The kit came with just barely enough hose:


The trickiest part was accessing the connection to the factory tubes. The connection is in a tight spot under the cross member. The hoses in the kit were a tight fit on the factory barb (I guess that's good?) :


Finally, I closed the factory radiator cooler. I was tempted to leave it open, just to see if and when it ever springs a leak




During the test drive the ambient air temperature was about 25F. I drove it a few miles with some hard starts and accelerations around my neighborhood streets. It seemed to shift fine with no signs of undercooling. After about 20 minutes the Tru-Cool felt "luke warm"; I'd estimate around 120-130 F?? The next step is to install a gauge.

 

Keep an eye on those hoses where they go through the sheet metal. Those holes can sometimes have sharp edges that will cut into the hose over time. I like to put some protection around the hose where it goes through sheet metal.


Other than that it looks good. You can always pull the hose off the radiator cooler later and see if its failed, and you don't risk losing all your coolant 500 miles from home.

 

Alittle offtopic but how easy is it to bend the mounting brackets that come with the kits?

 

Not too hard, I put them in a vice and hit them with a BFH until they conform to my wishes

 

Thanks.