Which gear to tow in?

Hate like hay to ask, but the more I read about towing, the more my head swelled...scenario-- 2010 V6 quad cab short bed/4x4/ automatic/factory tow package, electric brake controller being installed, will pull at max 2700-3000 lbs. an A frame camper, a few steep grades, bout 75 miles...Has 4D--3--2...thinking on the hills/grades have it in 3rd, flat in 4D??? Used to have a Suburban/pop up, never an issue...thanks in advance...

 

your fine dont over think it. Leave it in D (5th) as long as you can hold 5th gear in lockup and its not hunting between 4th n 5th a bunch. Hills you will need 4th and possibly 3rd / 2nd,

But really, just let the trans do its thing in D, and if it starts hunting a bunch, pop her in 4th.

 

I have the same truck, except 2013. Pulled a A-Frame pop up full loaded, never knew it was there. Pulled it over pretty steep grades. I pull a 22ft toyhauler now, it's 3400lbs empty.

 

1st gear FTMFW! JK, don't listen to me!

 

It's an automatic.

Let it auto.

And as @nd4spdbh says above,

Personally I'd be more interested in installing something like a ScanGuageII so I could monitor the trans temps. You may then find value in changing to syn trans fluid (can run higher temps) and/or adding/upgrading the auxillary cooler if required.

Fluid degradation from heat is more of a potential issue than shifting.

 

The reason why i bring up hunting is not necessarily the wear from the shifting, but the fact you are constantly unlocking / locking the torque converter / clutch packs you generate much more heat vs staying in one lower gear and letting the motor spin faster.

Heat is the enemy of the auto trans

 

If you have the tow package you are good up to around 6500lbs. I pull a boat in excess of 3000lbs with gear and up until recently I always towed in D and let the tranny figure it out. I recently read in the owners manual under “towing tips” that you should not tow in D. So you would be safe to put it in 4 and leave it there while towing. I think you are ok if you want to tow in D on level highways and cooler weather. But when towing hilly or mountainous terrain and/or hot weather or heavy loads keep it in 4. Towing in the mentioned conditions in D causes the tranny to shift excessively which can cause the engine or tranny to overheat.

 

Got it, thanks much for the info, free Dilly Bar coupons for all...

 

The owners manual will advise you to use "4" not "D" when towing anything. This prevents it from shifting into 5th (overdrive). As a default answer that is very good advice. But with loads that light you can probably get away with D under some conditions. I'd strongly advise using "4" most of the time. If you are on level ground, or going down hill at lower elevations you can try shifting into D which will allow it to go into overdrive. But on even mild inclines I'd manually shift back to 4 BEFORE the engine starts to strain. You can get by with leaving it on D, but long term your transmission will last a LOT longer. When towing anything heavier, on inclines, or above 4000-5000' elevation simply forget about D when towing. Your engine loses about 3% of it's power for every 1000' you drive above sea level because there is less oxygen in the air.

In fact I don't even use D most of the time when driving around town even when empty, or anywhere that speeds will remain at or below about 50 mph for extended periods. It just runs better and at those speeds OD isn't helping fuel mileage at all.

It is heat that kills automatic transmissions, not miles. Towing in OD causes a lot more heat in the transmission. It is a lot cheaper to get 1 mpg worse fuel mileage than replace a transmission.

 

Unless you are using an ultragauge or scangauge to monitor transmission temps I wouldn't recommend towing in D. Personally, I keep it in 4th and downshift to 3rd (or 2nd) in the mountains because the transmission hunts for gears at some speeds which is when I see the temps start to climb pretty quickly. Good news is the lightweight pop-up should be an easy tow with minimal wind resistance.

 

I tow a 5,400lb enclosed trailer in "D" until it starts hunting, then I put it in 4th. I tow in pretty hilly country all summer long. 140k miles on the truck now, zero issues.

 

What do you see for transmission temps when towing and how often to you service the transmission?

 

The trans gets serviced every 30k. I have a scangage and I started out monitoring trans temp like a hawk. In the hot summer months drinving 65 on moderate rolling hills with some auto downshifting/upshifting I'd see a peak of 195-196 on the up, and it'd cool right off to 140-150 going down. On hills where it hunted a lot, I'd see 205, so I'd put it in 4th. Larger hills were the same temps. It was so consistent, I just drive it now and don't worry about it.

 

Not bad at all @F-125Racer. Maybe it's the altitude or the size of my trailer but my temps climb pretty quickly if I tow in D. Even in 2nd and 3rd I can get temps up to 245 at the torque converter when towing in the mountains.