after by-pass, and with no other mods such as additional trans cooler or cooling fan, does anyone have experience or input with lightweight towing?
i may need to tow a small cargo trailer (approx 2000-2500 pounds maximum) about 450 miles with little or no city driving (almost all interstate) and am wondering if an additional cooler is really necessary (i'd rather not add one)
thanks

I've towed my brothers car with a car dolly and i tow two four wheelers on a small trailer pretty offten with no problems. I doubt the pathy will even know its there!

Based on some of the info presented by others on the forum, I don't think the rad cooler is really there to cool. It definitely helps warm up the trans when its cold.

The ~1sqft cooler seems to be more than adequate to cool the trans, and thats when I tow big. I've only done it a couple times since I did the bypass, and I will be installing a tranny temp gauge this season to make sure I'm right.

t

I just towed a 4x8 UHaul from Oakland to Seattle in the rain & got 15.6 mpg running about 65 mph. I guess the trailer loaded weighed about 2000 #. No problems towing it.

I did the mod a few years ago and I tow 3 trailers a lot:

1- 6'x5' enclosed trailer that I bought for football tailgating is about 800-900lbs and is about the same height as the Pathfinder. When empty it bounces a little so I can feel that back there, otherwise, it tows like it isn't even there. I pull it around town with the OD off, but when I get out on the highway I go ahead and let it run in OD. If it changes my MPG, it's by less than 1MPG. Since getting it, I also have used it on long road trips to carry luggage since it pulls so easily.

2 - 12' heavy duty open trailer that is somewhere over 1200lbs and has a very high dovetail type gate. I can feel this back there, I tow it with OD off most of the time, unless I'm moving it empty on the interstate and can have the back gate folded down so it isn't catching the wind.

3- 22' boat that, depending on how we have it loaded up and where we are going, it going to be in the 4000lbs-5000lbs range, and I often run with a full load in the truck too when on the way to the lake.

I don't have a tranny temp gauge - BUT I have drained/filled the fluid several times. It looked a little burned the first time I changed it years ago, but since then has looked great. I credit the difference to being sure that when towing the boat, I don't let the tranny slip and build up heat, and run it at a speed/throttle position so that whatever great it's in, it's locked up. Basically this means I don't get to set the cruise on 65 and ignore it.

so apparently, medium weight highway towing shouldn't be an issue with a by-passed in-radiator-trans-cooler
i really don't want to put in an aftermarket radiator, and due to the logistics, an additional cooler and/or fan isn't really an attractive option either
thanks for the responses!

same scenario would apply to someone towing small (not even 2k lbs) with a 2WD path too? should be ok?

amr40509 wrote:I did the mod a few years ago and I tow 3 trailers a lot:

I credit the difference to being sure that when towing the boat, I don't let the tranny slip and build up heat, and run it at a speed/throttle position so that whatever great it's in, it's locked up. Basically this means I don't get to set the cruise on 65 and ignore it.

this is my first vehicle with an automatic transmission, and will be my first towing experience............
how do you know when it's slipping, and how do you know when it's "locked up"?

eieio - I have a gauge on mine and despite a couple decades of towing experience, the readings are much different than I expected. On the interstate = low tranny temperatures, dense city driving or steep hills = higher tranny temperatures, backing a trailer up a hill at .01 mph = really high temps. You said you're going to be on the freeway so you should be fine. I do have it bypassed with double coolers and a fan, but still, I usually read below 150 going down the freeway even with a trailer.

eieio wrote: this is my first vehicle with an automatic transmission, and will be my first towing experience............
how do you know when it's slipping, and how do you know when it's "locked up"?

FYI…
Nissan has designed 5th gear to go into torq converter lock-up [above ~40-45mph] but not so for 4th gear [as in NEVER]. According to the serv manual, the trans will go into partial lock-up under certain condition & times. Just haven’t figured out just when.
Complicated, new-fangled stuff to keep engineers employed. I even asked the service writer at the dealership if there was a computer upgrade available to modify that, the answer was NO. When I had my 98 Tahoe, there were guys who would tweak the computer slightly, but have seen no one willing to tackle the PF. Guess it is truly a different animal. To me, failure to lock-up means slush-o-matic which equals heat buildup. Yet this is the same power setup as in the Frontier truck, so it must be OK. Just I’m not totally convinced, since a lot of fuel has to be wasted, but then the trans may not be sturdy enough to handle direct coupling in 4th??? Heard that it will lock up in 3rd, but have not checked it out yet.

When it is time to get another vehicle, you can be sure this IS a question that will be asked. Maybe a Frontier crew cab with MT is where I am forced to go???