replace and upgrade radiator on 99 4WD 6 cyl Auto SR5

I think the radiator is factory original. a denso tag on the top of it. I want to upgrade the transmission cooler, for some desert cruises coming up this summer. was reading about a Gen 5 radiator upgrade that apparently increases the transmission cooling. did not see any results of temperature differences with that install.

reading about the Gen 5 radiator install, it sounds as if it will solve overheating tendencies. i have read that Gen 3 can overheat also. I wonder if anybody here has replaced the stock radiator with stock, or with upgraded performance, or with an inline transmission cooler.

i worry about the pink milkshake issue, and want to know if can only be avoided by replacing the original radiator. it's over 200,000 miles, but might have been replaced earlier, idk.

i would appreciate links to articles, or information about whether there are bolt-in radiators for the Gen 3s. my main goal is to protect the engine and transmission in high ambient environments off road. thanks in advance,

standard sends

 

Lots of people use an external transmission cooler.

https://www.youtube.com/watch?v=34wnfq85_qk



Remember, you don't want to overcool your transmission. Then it doesn't work right. In the vid above, Tim discusses that the cooler he uses has a pressure bypass (like a thermostat) that allows the temperature to get up to correct operating temp before it starts cooling.

I believe he fully bypassed the radiator...so no pink milkshake.

That way, you could use any engine radiator that fits for max cooling.

 

thanks for that link. i'll watch the video in a bit. i think you are saying that with a new separate radiator i can just rely on air cooling for the transmission?

the second concern is about my original engine radiator. i am still interested in replacing it because the failures seem to overheat the engine. and the engine seems to hate being over heated. is this correct?

in any case i am interested in increasing the cooling capacity of the engine.

thanks for taking interest in my project. it has to get me to the big family reunion in Texas, with various side trips to even hotter places. good night

 

Yes, watch the link. I believe he bypasses the entire radiator completely and he mounts the tranny cooler in front of the engine radiator.

Not sure what people do for upgrading the engine radiator...but with the transmission disconnected completely, it should be easier to find something larger.

 

It's up to the owner to bypass their transmission cooler or not; personal preference really.

I ran a B&M Supercooler transmission cooler, after the stock radiator, on my 4Runner. I used Gates transmission lines.

If you're genuinely worried, just run a temp monitor on the return end and see how hot you're running. And unless you're leaving OD on, and/or towing uphill in said desert, you'll have no issues.

Goes without saying, you should completely drain your transmission and replace with new fluid the same time you replace your coolant and radiator.

 

thanks for the input. i bought a new radiator, and i'm thinking i will run the oil thru the radiator and then into the cooler. i plan to put a gauge on it, i was thinking a tee on the output line. was also thinking about a magnetic filter right there too, but don't know if it is a fad, or a good idea.

i'm thinking i should change all the fluids before i work it thru the deserts. does the transmission drain itself dry from the drain plug? and if you know, what is the correct quantity to put in?

thanks again.

 

Transmission pan already has magnets in the pan to hold onto shavings. Magnetic filter won't do much. Won't hurt either.

If you don't know the state of the transmission, it's probably best to at least drop the pan, and check those magnets. If there is next to no debris, then you can change the filter and refill. If you see a lot, you may be in need of a new transmission. Putting the pan back requires the TOYOTA liquid gasket or a FelPro gasket. I went with the FelPro for easier filter replacement. Do not clean the filter. You can't. Just get a new TOYOTA one.

To completely refill the transmission, it takes 24qts or so and you have to do a drain\fill\drain\fill\drain\fill dance. Plenty of vids on youtube. Total amount the transmission holds is actually like 16qts I think but it's not really relevant and it will take more to do a fluid change and you'll fill it as per your dip stick.

 

i think this stuff up somehow. i think i will go with two Hayden 699 coolers. i will make the templates tomorrow to double-check the space they need. and i think plenty of cooling. and no oil in the radiator. and no water in the oil cooler. it's easy to adjust them in winter with cardboard if they over-cool the transmission. that's how it's done in Fairbanks. or was at one time. ciao Runners