At what point do I need to upgrade?

I have a 2017 SR double cab as stock as can be so no tow package or anything like that.

At present I'm not towing all that much. A single-axle utility trailer with homemade stake sides and gate. I'm guessing about 1,100lbs or so empty.

I believe I should be able to safely pull up to 3,500lbs gross weight, shouldn't I? Don't foresee approaching that with my current trailer.

But I am considering a bigger trailer so what I need to know is at what point would I be well served in bulking up the leaf springs and possibly adding a transmission/motor oil cooler?

I tend to keep a vehicle until the wheels fall off so I don't want to put a lot of unnecessary stress on this one. If I go to a larger trailer and come close to pushing the envelope I'll beef it up. But at what point do I need to start considering this?

 

You can do any and all of that but it won’t increase the manufacturer weight and tow specifications.
As long as you don’t exceed manu specs you are good. Adding the tranny cooler, oil cooler and better springs is a good idea especially if you are towing at or close to the limit. It will prolong engine and tranny life.

 

If you do not have a tow package, how are you towing? Did you add a factory or aftermarket receiver? An aftermarket bumper with built in receiver?

Your current tow capacity depends upon your equipment.

 

I had an aftermarket receiver (

$170 CURT 13264 Class 3 Trailer Hitch, 2" Receiver, Fits Select Toyota Tacoma , Black

https://www.amazon.com/gp/product/B0193HXA7K/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1) mounted and the trailer manufacturer wired the lights for me.

 

I would consider at least adding the tranny cooler of your going to be towing more than 2000 lbs. B&M makes a good cooler http://www.bmracing.com/products/70...oler-small-supercooler-9800-btu-rating-black/. It's easy to install if you know what you are doing.