Hello. I'm looking for some feedback. I have a 08 4Runner with 303k miles. I installed a class 3 hitch a few years ago. The only thing I have towed is a motorcycle trailer over a short distance.

My wife was working out of state in FL for a few years but will be coming back to IL. We are looking at options on how to get some of her stuff back. E.g., PODS, moving truck or a trailer. Clearly towing a trailer would be the least expensive option, but I don't want to discount the wear and tear on the truck.

Would you guys have any concerns with towing a 6' x 12' U-haul trailer around 1300 miles? I do not have a transmission cooler.

I am leaning towards renting a truck or using a POD but wanted to see if renting a trailer is an option.

thanks!

You're the only one that knows how well maintained your truck is. Personally I'd do it. Just keep an eye on the trans temp on any grades. Make sure your cooling system is all in good order.

I would like to say everything is in good order. Water pump and thermostat was recently replaced. Aside from the trailer weight itself, the trailer would have a couch, computer desk and two full size beds including box springs (no head boards).

I remember hearing about folks adding a transmission cooler. Maybe I need to consider that. Also, what transmission temperature is considered high?

@zguy1 - I have an '07 V6 with 241K miles and I wouldn't hesitate to make that trip in my truck. Your concern appears to be around potential failures directly related to towing the trailer (assuming you would have no qualms about making the trip if not towing). The 4R is designed for towing and the V6 has a small internal transmission fluid cooler - check the driver's side of the radiator to see where the piping goes in and out - and it sounds like you won't be anywhere near the 5K max towing capacity. There's also an A/T OIL TEMP light on the dash that will alert you to a fluid overheat, assuming it's working, so you'll know to stop and let things cool off a bit if necessary. One important note: check the owner's manual as it says to tow in 4, not D. IIRC, this isn't even in the towing part of the manual. It took me a long time to find it when it came up in another thread.



I'm not trying to talk you into anything as this obviously has to be your decision alone, just throwing in my 2 cents as requested. You should do whatever you're most comfortable with.

I hope to go on the road with a travel trailer one day and thus installed an external cooler. You shouldn't need one for your trip (IMO, YMMV) but my writeup is here and has a link in it to a post about the bypass I decided to add. (The bypass excludes the external cooler from the loop unless the temp rises above 180 degrees. Apparently additional full-time cooling can result in too low an A/T temp than is healthy. That surprised me as I always thought cooler is better, but apparently that's a thing.)

Curious to know what you decide and how it goes. If your route goes through or by Atlanta, PM me for my mobile number. If you have any issues within a reasonable drive of where I am, I'll see if I can help.

@Bluesky 07 - Thanks for the response and the information. The truck is running great. I am actually on a road trip and currently in Colorado. This is my first one after the head gasket repair I did.

I am still tossing around options but using the truck is becoming more of an option.

Btw, I know the cooler is optional, but if I decided to take it on, how much would the kit you used cost? How much time do I need to install it? I tend to move slower when doing things that I have never done before.

Also, the first link for the valve points to a YouTube video, not sure if that was your intent. Thanks!

The YT video was intentional but my wording was way off. I've edited that part of the cooler post and it's now clear (or more clear at least lol) that the video is about lower temps not being better for ATF. I also added the actual link to the bypass valve writeup. Thanks for the heads up, I don't know what I was thinking when I wrote that.

I am the same way about things taking longer than it feels they should. Trying to remember but I'd guess ~4-5 hours on the cooler. I was doing a fluid exchange along with the cooler installation; if you don't, you may want to top off or at least check the ATF level, which is a bit of a PITA as you may know. @Drcoffee may have some input as he also did this mod.

To install a trans cooler you will need a quality plate cooler like the B&M 70264 which can fit either on the left or right side of the condenser. 4’ of 3/8” ID cooler hose (I prefer Gates). And some hose clamps. All in $100+/-.

The process is easy enough. Unbolt the 4 radiator bolts from the rad support and lean it back but be careful not to let it rest on the fan blades. Afix the cooler to the ac condenser with the included zip ties, and route the cooler line around the drivers side of the radiator. 2-3 hours should be enough for a first timer. ATF flows into the upper port and out the lower port on the radiator. I run the ATF into the lower port on the cooler after the radiator. You can do it either way.

i bought the csf trans cooler that you attach in series with the radiator. bought off rockauto, the stock mounting locations can be used. your suppose to buy the bracket for the right side and some grommets to hold it tight in place. i just used a spacer for the left side and used the bolt on the bottom, snugs it enough to hold it in place without buying the brackets.

a couple people upgraded to the hayden cooler which is way bigger.

Im not sure which cooler and brackets you have, but if its not mounted to the condenser, you dont get the cooling effect from the radiator fan which is free air flow regardless if you are moving or not. These coolers are not as efficient with passive air flow vs a dedicated pulling fan.

I tow a 13 foot camper full time for 2 years now. Put about 30k miles towing from Ohio to Tampa to Vegas to Wyoming now.

It chugs going up mountain passes and does overheat despite the temp not registering hotter. I get some radiator overflow then have to add fluid when I stop.

I just added a cooler today for my next legs of the trip and will see if that helps.

the v8's come with a stock cooler, the mounting holes are on the v6 as well. its mounted to the same place it would be on the v8, right under the horns in front of the condensor.

Thanks guys! Sorry for the delayed response. I just got back from my road trip last night.

Looks like the B&M cooler is no longer available. I started looking at the Hayden coolers. According to their website, they do not list the 698 version as an option for my 08 V6. There are several listed and some contain a bypass valve which sounds like that would eliminate the need for a separate valve.

Tru cool coolers are pretty solid units as well check out these low pressure drop coolers LPD4543 & LPD4544 which have the 3/8” barb ports

Tru-Cool LPD Transmission Oil Coolers. Protect Your Investment. | Tru-Cool

So I was able to spend a little more time looking into oil coolers and reviewing the information and links you have provided. I do have a couple of questions though.

1) Since the LPD coolers (LPD4543 and LPD4544) and the Hayden ones (697, 698 and 699) all have low temperature bypass ability built in, is there a reason to purchase a separate bypass like the Derale thermostat bypass valve?

2) I was going to ask if I needed trailer brakes, but it looks like the larger U-Haul cargo trailer 6x12 has surge brakes so I suppose I'm covered there if I choose this over the 5x8 one. Is my understanding correct?

3) Regarding hose clamps for the 3/8 inch lines, should we using the factory style clamps as opposed to the worm style clamps? I know some folks do not like to use the worm style as they do not expand and contract with temperature changes since they are fixed.

thanks...

1) i had the tru cool with LPD and my tranny never got above 135*F. Thats too cold. The bypass allows the tranny to get hot enough to vaporize condensation within the unit.

2) if the trailer has surge brakes, you are good to go. You might want to consider upgading your front calipers to the sport version brakes to help stop warping of the smaller rotors on the base 4runners.

3) I never reuse the spring clamps. The factory hose has a different OD and they dont clamp tight enough on aftermarket hose. With worm gear clamps, make them tight enough so the band beds itself into the rubber hose where you cannot feel the edge of the clamp. Run it a week and retighten them