I have a 99' 4Runner that I will be using to tow a 6'x12' trailer with about 2000 lbs of cargo (so about 3500 lbs total weight) from Toronto to Vancouver (about 2,700 miles) at the end of the month.

I have heard that when towing you should always leave O/D off but would it hurt anything (other than my gas mileage) to do this for such a long distance? I don't like the idea of the engine revving above 3000 rpms for that long but maybe it's fine?

I do have an external transmission cooler installed (bypassing the rad completely.)

 

Trailer is equipped with brakes and a brake controller or trailer has surge brakes?

I would follow the owners manual.

 

Surge brakes but the braking ability shouldn't have anything to do with overdrive, no?

The manual doesn't really say much about using overdrive or not when towing.

 

yes turn the o/d off and when you get on say a highway where your not going up and down hills and such if it a flat surface then you can turn it back on its only when shifting alot and stop and go traffic that you want to tun the o/d off while towing

if you dont do this then the crush sleve for the o/d in your trans will continue to be crushed untill it can be crushed no more and then it has to be replaced and is usually very costly to have done

 

Say I want to just keep the O/D off at all times (mostly because I'm worried I'll forget to turn it off when I should) can it hurt the engine to run at a higher rpm for that kind of distance?

 

no not at all because actually those are more so the rpm's of the trannsmission and more so it would just b like your driving the same distance with the o/d on and running about 80 to 85 mph

 

Leave O/D off, that way the torque converter will be able to lock up and not hunt back and forth.. You could drive around the world at 3500 RPM with that engine.

I've never heard of this crush sleeve thing, but the transmission will heat up if the torque converter is slipping.

If you do try and use the O/D keep in mind that 2 things happen.
1st the tranny shifts into O/D (4th).
Then the TC locks up a couple of seconds later. You can tell when it locks up as the rpm's will drop a further 500.

If the rpm's jump up and down by 500 then you know the TC is kicking in and out.

 

Absolutely keep the OD off, I towed a 4000 pound trailer 700 miles with OD on and ended up doing 2k worth of damage to my transmission. With the tranny cooler and cold temps outside, you should have no problems eliminating the heat from the transmission. I would also recommend you hit the ECT Power button to give you better shift points.

Needless to say you should do a thorough checkup before setting out on such a long trip. You probably ought to change the engine oil. Be sure to check ATF, brake fluid, and coolant levels, and keep extra fluids with you. Check tires, including the spare and the trailer. Ensure belts and hoses are in good shape, maybe even bring spare belts, and a few wrenches to work with. Good luck, and let us know how it goes.

 

Thanks! I'll keep the O/D off for sure and try the ECT out as well.

I just changed oil, ATF, flushed the coolant, did the tundra brake upgrade, new tires etc

Going to have my mechanic buddy do a full checkover before we head out as well.

 

Sounds like you've covered all your bases. Just remember to take it slow and safe.

 

In Canada I always drive with OD off.

 

Oh yeah. That metric system will really screw up your O/D. It's ok in the US, but not up north.

 

Porbably don't want to make the drive - ie. A Torontarian will not make it in Van City. Its probable that your tranny will burst into flames upon crossing the B.C. border, leaving you in Alberta, which you would likely find more suited to your 'tastes'.

Cheers!