MoparNut

2 weeks ago I towed my 24' V-nose car hauler with my car inside. Trailer weight I'm guessing about 7k-7.5k lbs? We went 230 miles from IN to Ohio (flat roads). The trip over there was pretty easy and I got 12mpg. The trip home was not so fun and came out to 9 mpg! We had some head winds, maybe 10-15 mph, I could see the trees blowing a little. Around Bellefontaine, Ohio there is a fairly steep hill on US33 (probably the steepest in Ohio), I had the cruise set at 65 with the air on. The tranny down shifted to 3rd going up the hill and would not go back to OD. Everytime I had to stop and start the tranny would not go into OD unless I completely let off the pedal. Even letting off a little to slow from 60-50 mph, no OD until I let go of the pedal. Going along on flat road at 60mph and not moving the throttle for 5miles it would not shift to OD. Is this normal? My thinking is I had to really push the pedal down to get it up to 65 mph by then the pedal is so far down that the tranny won't go to OD. When it did go to OD It seemed to have plenty of power, I could accelerate from 50 to 65 pretty easy. Can this be recalibrated by the dealer? I'm not buying any chips. BTW I was using tow/haul the whole trip.
One good thing since this trip my milage has went up 1 mpg. I now have 9500 on the odometer.

92DuallyCTD

You were probably riding that ragged edge of downshift/upshift in and out of O/D with the headwind at that speed. Since the final shift into O/D is controlled by the computer, and gets a feed from your throttle position sensor, the cruise probably had the throtte depressed just enough to keep the O/D off, unless you sped up and let off the throttle a little. Also may have a little to do with the 'intelligent'(carefully spoken around cars & computers!) system on newer vehicles that 'learns' the driving characteristics/conditions. It sounds prety much normal to me, about the only thing you can watch is how it acts in the next several miles. Don't think you'll need any recalibration this soon, hope not anyways! Good luck to you, drive safely! :-)

coparam4x4

I pull an 11k toyhauler mine does the same thing except I found out that once I get up to 65mph then it will shift into OD if I dont have the throttle wide open. Try that next time you pull, keep accelerating steadily up to 65 then it will shift into OD. It took me a handfull of trips to finally figure out how this tranny wants to shift when pulling a load.

$oC@l CTD

Also, what gears do you have...3.73s or 4.10s? If you have 4.10s, get her up to 65mph in tow/haul mode, maybe even 70 and THEN set your cruise. You will be at about 21-2200 RPMs at 70, your torque converter will be locked and at that speed, it won't kick down and you'll be in your optimal hp/tq range...your truck will like it.

One other factor...I see that you have BFGs, what size are they? Because if they are bigger than the stock 265s, you WON'T be running 21-2200 RPMs at 70mph and anything lower then 70 or so and your torque converter WILL kick back down into 3rd. It's kind of an art, getting to know your truck, it's shift points and all that when you're towing...but once you do, you'll LOVE it! I pulled this load (10k boat) for about 30 miles on the interstate and experienced a few hills, nothing serious though and once I was up to about 65-70, never had a problem. Now starting off with that kinda weight on a hill is a bit tougher, but we won't get into that!

2RamsNoCash

my 98.5 gets 14 worst haulin 14k through mountains guessin deep gears there.but my best ever was 21.Bill

MoparNut

[QUOTE=$oC@l CTD;1532807]Also, what gears do you have...3.73s or 4.10s? If you have 4.10s, get her up to 65mph in tow/haul mode, maybe even 70 and THEN set your cruise. You will be at about 21-2200 RPMs at 70, your torque converter will be locked and at that speed, it won't kick down and you'll be in your optimal hp/tq range...your truck will like it.

One other factor...I see that you have BFGs, what size are they? Because if they are bigger than the stock 265s, you WON'T be running 21-2200 RPMs at 70mph and anything lower then 70 or so and your torque converter WILL kick back down into 3rd. It's kind of an art, getting to know your truck, it's shift points and all that when you're towing...but once you do, you'll LOVE it! I pulled this load (10k boat) for about 30 miles on the interstate and experienced a few hills, nothing serious though and once I was up to about 65-70, never had a problem. Now starting off with that kinda weight on a hill is a bit tougher, but we won't get into that!


I have 3.73s and stock BFG tires. I think it's running 1900-2000 rpm @70.
Another question. When your accelerating from a stop how much throttle do you need? it seemed like I had to give it 3/4 throttle to get it rolling up to 65. I think that's why I only got 9 mpg. Maybe I need to be more patient while it's accelerating?

$oC@l CTD

I have 3.73s and stock BFG tires. I think it's running 1900-2000 rpm @70.
Another question. When your accelerating from a stop how much throttle do you need? it seemed like I had to give it 3/4 throttle to get it rolling up to 65. I think that's why I only got 9 mpg. Maybe I need to be more patient while it's accelerating?[/QUOTE]

I just slowly roll into my throttle...the reason that I can take off a bit easier than you can from a stop is because of my 4.10s. The bad thing about 3.73s is that in order to make SURE that your truck doesn't kick down a gear in the steeper hills, you have to be going faster than we with 4.10s do (either that or get an aftermarket tranny with a torque converter lock out switch...or just a lock out switch period). Well, sometimes 75-80mph just isn't safe when you have 10k+ behind you. I NEVER get over 65-70mph when I have that much weight behind me (preferably 65). I would rather just slow down and turn over drive off to climb a bigger grade than to get up to excessive speeds when I have loads that outweigh my truck behind me, regardless of whether the trailer has brakes or not. That's just one of the disadvantages to having 3.73s if you tow heavy often in my opinion...on the other hand you have the luxury of better fuel mileage

truk

i tow around 9- 10000lbs enclosed car trailer. i dont use tow haul. i tow from dayton ohio to pitts pa lots of hills! i set the cruse at 65-68 and roll . it never leaves overdrive un less i have to slow down alot. i get 10mpg in hills or on flat ground with box with out it .all milage hand figured.if i go by overhead 17.5-99.9 depends on going up or down lol .i know the area you where in you should have eat those hills alive!!! as far as starting off i was told get to o d as soon as poss. ! i dont know its just great to have these awesome trucks