Towing in 3rd or drive

[Nick1994]

Tow vehicles are a 2002 Chevy Trailblazer 4.2L I6 w/ 4L60E & 1996 Jeep Cherokee 4x4 4.0L w/ AW4 auto tranny.
Both vehicles have tranny coolers.

Trailer is about ~500 pounds and the truck bed on top is about ~500 pounds. Sometimes I haul the ATV (also about 500 pounds) and sometimes I don't, sometimes I haul other stuff. Trailer will never weigh over 2,000 pounds.

Do I tow in Drive or 3rd gear? And which do I use when? Sometimes I tow the trailer at 75 mph for about 100 miles of interstate driving other times it goes across town or to Home Depot.

Fuel economy goes way down in 3rd gear when out on the highway.

Thanks for the info.

 

[supton]

I thought for the older 4spds, some actually had weak OD gears. But these are not of that vintage. Otherwise, what hurt them was either hunting under power, or when they would unlock the convertor but not actually shift down, forcing high slippage and lots of heat while in top gear.

Pretty sure on these two you can use OD. If it won't stay locked up or wants to hunt, then do 3rd.

 

[supton]

Although looking at that wind load, I am guessing both vehicles will prefer 3rd at 75mph, even on level ground. Just a guess.

 

[Ramblejam]

Serious question...

When things break on both of these trucks, do you pay for it, or is someone else footing the bill?

If someone else, then keep running 75MPH in OD, because they're going to fail.

If you, then slow down, install bigger coolers, monitor temps, and lock out OD. Even when new, neither one of these transmissions excel under trailer towing conditions.

 

[spasm3]

I tow out of overdrive.

 

[sciphi]

Probably 3rd. Save the transmission. Neither one of those transmissions are known to be particularly stout units. Even with aftermarket coolers.

 

[user52165]

What are the rear end gear ratios? Are you towing on flat terrain or up Interstate 17 towards Flagstaff?

 

[Nick1994]

The vehicles aren't mine, they're my grandparent's. A lot of the use of the trailer is for them, hauling stuff to the dump or going to Home Depot.

Trailblazer has a 3:73 gear ratio and Jeep has 3:55.

Interstate travel is on the I-10 toward California (flat) and sometimes I take it to Prescott on the I-17 (mountainous)

 

[Ramblejam]

Originally Posted By: Nick1994
The vehicles aren't mine, they're my grandparent's.


I figured as much.

Stop driving like a dumb college kid and respect their vehicles.

Slow down, lock out OD.

 

[Nick1994]

Originally Posted By: Ramblejam
Originally Posted By: Nick1994
The vehicles aren't mine, they're my grandparent's.


I figured as much.

Stop driving like a dumb college kid and respect their vehicles.

Slow down, lock out OD.

Um, excuse me?

 

[nwjones18]

With that trailer I'd run in OD unless it felt like it was lugging. I also generally don't tow any faster than 65.

 

[SwampSurvivor]

As long as it doesn't seem to be struggling or unlocking the torque converter, you can tow in OD. Note that the 91 and newer HO 4.0L engine likes to wind up a bit. They will get better mileage running in drive while towing.

You will not kill the AW-4 ... it as put in much more powerful vehicles that were heavier. Make sure it has a trans cooler.

 

[Andrew1972]

Isn't towing 2000 lbs at 75 mph putting excess wear on a poor Cherokee.

Third gear would wind the engine out and I don't understand driving that fast with a homemade trailer that appears to be a wind block. Seems a tad dangerous at that speed with subpar brakes a jeep has.

Be kind to your grandparents nice suv.

 

[supton]

This is in the wild west known as Arizona, right? Isn't 75 like what you slow down for in school zones?

 

[Nick1994]

Originally Posted By: madRiver
Isn't towing 2000 lbs at 75 mph putting excess wear on a poor Cherokee.

Third gear would wind the engine out and I don't understand driving that fast with a homemade trailer that appears to be a wind block. Seems a tad dangerous at that speed with subpar brakes a jeep has.

Be kind to your grandparents nice suv.
75 mph is the speed limit on the highway, and the Jeep is rated to tow 5,000 pounds, Trailblazer 5,700 pounds. The Jeep has been bulletproof and gets beaten hard on rough dirt roads when taken out to the desert. Doesn't skip a beat. It's getting new leaf springs probably this weekend.

 

[SwampSurvivor]

Biggest downside to towing with a Cherokee is the awful brakes.

Engine, transmission, suspension are great.

 

[supton]

The more I look at it, the more I wonder about braking 2k with a twenty year old Jeep, 75mph or not.

My money says you wind up in 3rd at 75 when you do this.

 

[Nick1994]

Originally Posted By: Miller88
Biggest downside to towing with a Cherokee is the awful brakes.

Engine, transmission, suspension are great.
Yeah the brakes suck! They are god awful. He's owned the Jeep for 8.5 years and 37k miles, brake pads still look like brand new and it gets lots of city driving. They squeak like crazy and drive me nuts but they still stop.

Originally Posted By: supton
The more I look at it, the more I wonder about braking 2k with a twenty year old Jeep, 75mph or not.

My money says you wind up in 3rd at 75 when you do this.
I've towed a 1974 Chevy Nova on a 2,000 pound Uhaul car hauler trailer with the Jeep (about 5,000-5,5500 pounds total). It did just fine.

But I'd slow down to 65 if I'm in 3rd gear.

At 75 mph I'm practically getting run off the road on I-10, 65 mph won't be too fun but I don't want really high RPMs

 

[super20dan]

75 is way too fast to tow any trailer.

 

[Rolla07]

Yeah 75 is too fast when towing. For some drivers 75 is too fast when not towing. Tow in drive and slow down a bit, let the cars pass you.