I plan on towing a boat (@ 2500lbs) my question is pretty simple, do most of you just switch the overdrive off (auto) when towing heavy? And any other suggestions, thanks...

 

You are supposed to per the owner's manual.

 

What about a utility trailer?

I towed mine today with my somewhat newly acquired 99 4runner. Its a 5x12 with concrete forms as decking and 1.5' sides. The metal is pretty thick C chanel and it was custom built to haul ATV's but was converterted over as a utility trailer. It has a 3,500 lb axle and 265/70/16 tires (on Taco wheels ).

Anyway, I have no idea on the weight. I towed it unloaded about 30 miles and picked up 3 windows so apprx an additional 250 lbs or so.

I took the freeway and left the O/D off so I was speeding along at a mild 50 miles per hour so it was slow going. It would have been nice to have the extra gear and bump up the speed, but I didnt want to risk any issues.

 

Just some recommendations.....

For the near term I would:
1. Never, ever tow in O/D.
2. Check your ATF. If it is old (not red but dark, smells burnt), drain it and replace it.
3. Check both front and rear brake pads for wear.

Long run (using the Runner as the primary tow vehicle for years):
1. Tundra brake upgrade.
2. Install an external transmission cooler such as the Tru Cool 4454 or B&M 70264. In fact, you may want to do this one sooner than later knowing how hot the summers can be in SC.....

 

Absolutely do NOT tow with the Overdrive on!! I got my 4Runner a couple months before I left college, and used it to tow a U-haul about 800 miles and ended up doing $2,000 of damage to my transmission. I had never towed anything before, and it was my first car with an automatic, and since I'm an idiot I didn't ask anybody for help. Save yourself the money, and always turn the O/D off. The transmission is much more delicate and fragile than the motor.

Also, the brake upgrade and tranny cooler are a must if you plan on towing a lot. The tranny cooler I would recommend even if you're not going to tow; it's a cheap, quick install and it eliminates one of the biggest flaws for these trucks.

 

Okay, O/D off no matter how light the load.

Already did the tranny cooler bypass and the rotors and brake were installed at dealer before I bought it.

I dont plan to do a lot of towing, just occasional for home improvement / yard work runs.

 

I will give an example of one the few exceptions to this rule of "never tow with O/D on". If you are on a long flat highway and you are going say 55 mph, as long as the tranny isn't struggling to keep up speed, the momentum is moving the vast majority of the load. The truck is pulling very little extra weight in this instance (no more than having say an extra person or 2 in the truck). Now if you're sitting there pushing high 2000s or 3000+ rpms at 55 on a flat highway towing a trailer, you are working your engine very hard and wasting a lot of gas by driving with O/D off.

All that excess engine wear and loss of fuel efficiency is all just so your tranny won't have to pull ~5% more than it's normal weight (once it's already moving). When you get to an incline or decline, turn the O/D back off, but on the flat it's causing more harm and costing more money than what it's saving on your tranny.

 

^^ Good info.

I just kept mine around 50-55 and tried to keep the RPM's at or below 2500. I imagine my trailer weighs ~ 500 lbs or so, and that is a blind guess.

The runner had no issues pulling it and I didnt really know it was there. I am sure I could have kicked the O/D on when cruising on the flat areas.

 

I tow in O/D most of the time. Light loads in a utility trailer or our small pop-up camper. As long as the truck isn't constantly shifting out of O/D to make it up hills, you're fine. If you find that it is, switching out of O/D will keep the ATF cooler. This is easy to see with a scangaugeII and the ATF X-gauge. I found that until TPS (throttle position sensor) hits about 26%, the truck will stay happily in O/D. Beyond that, and it wants to shift out. Once it doesn, the ATF temp rises quickly, but does moderate after a few seconds.

 

I have a tranny guage and as long as the torque converter is locked its not going to heat the fluid which is the biggest deal. If you can keep it in O/D without it shifting everytime the wind blows then your fine. If it keeps shifting then take it out of O/D. That simple. I get better fuel mileage at higher speeds since im at a higher RPM and my engine doesn't work as hard for example. It won't hurt the engine to run 3500 RPMs for a long time either. I used to do it from NC to KC all the time when I was going to school.

 

If the torque converter stays locked all the time, that's one thing. The thing that kills you is the clutch packs in O/D are nowhere near as robust as the ones in 3rd. Plus, in 3rd most of the gears in your tranny are locked up, reducing the wear.

 

I have towed a lot of stuff with my 93 .... IO'm currently using the rear end of a full size chevy p/u as my trailer for hauling metal, etc.... I turn the o.d. off for hills, but when cruising, I turn it back on....I'm also currently running a 4.10 rear in this thing, due to the grenaded 4.88(thats another story), and still no issues, I have used this rig to haul my other 4runner on a trailer for long distances, and hauled a u-haul trailer to nj and back..... ya just gotta use common sense...and get outta o.d. for the slightest incline.

 

One look at a OD planetary failure will have you thinking twice about towing in OD, justified or not.

Not saying this failure was because of towing but it might have been from some of that. https://www.yotatech.com/forums/f2/p...images-111443/

 

Like they say, pictures say 1000 words. That is just awful. Hopefully everyone sees the attached thread. Thus, even if the failure is linked to only 01-02s, never tow in O/D.......

 

A tranny shop I spoke to said it affects a lot more than the 01-02 4runners. He basically said all 4runners, Tacoma's, Tundra's etc...

 

WOW! That was just awful!! I will not be using O.D. when I tow anymore......

 

I gotta say, I owned a 2001 Taco TRD 6cyl auto and ALWAYS towed with O/D on. Landscape trailers and my popup camper. The truck has 140K on it now and the tranny is great. So, I'm certainly not disputing anyone's accounts of problems here...just saying that the tranny is fine after lots of hauling miles with O/D on.

 

trannys are to expensive to tow in O/D..

 

I find that encouraging.

 

ya well like I said...I have towed a lot of stuff with my rig, and usually have o.d. on, unless climbung a hill.... I also have a spare tranny in the garage.... so i dont care if I grenade this one....