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Discussion Starter #1
I own a 1500 quad cab with a hemi a recent hauled a quad in the back and pulled a 16 foot car trailer with 2 quads and 2 dirtbikes i know the truck can handle the weight and has plenty of power to do so. my complain is with the tranny on flat roads the truck did fine. as soon as starting up a grade the truck would hit upwards of 3700 rpms i had to haul on and i'm in illinois so i wasnt climbin a mountain. these are not steep grades by any means what can i do to fix this problem
 

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3700 is the middle of the powerband. That sounds about right for that kind of load.
 

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Thats where you get the most torque, so that is not unreasonable. Why do so many people freak out over rpms it doesn't hurt the engine.
 

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Discussion Starter #6
i tried cruise on and off and startin up the hill i was easy on the throttle to avoid that 1700 rpm jump in shifting...i'm not worried about the engine at all it the shift from just over 2000 to 3700 goin up a small grade and it taking forever for the truck to settle back to around 2300
 

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I always force the downshift manually, before it gets bogged down in the upper gear. This way it doesn't jump, instead it runs at an elevated RPM, which will be lower than what it "jumps" to when it is compensating for lost speed while bogged down.
 

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x2. Make it run at the higher RPM so the trans doesnt shift all of the time.
 

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I just towed a car last weekend and you are right, there is plenty of power but managing the trans is a pain. We've got a F550 with a heavy trailer at work thats the same way.

With tow/hual on you are in 4th on flat ground probably doing about 2000 rpms.

When you get to a hill, if you let it start to bog and then gas it it will downshift all the way to 2nd or 2nd prime at about 4000 rpms. With my truck, thats really more than is needed and I end up rocketing up the hill and probably wearing the trans more than I'd like.

At the base of the hill I try to stab the throttle enough to get it go to 3rd at about 3000 rpms. Once in 3rd, it would climb hills easily without up or downshifting.
 

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What year is your truck? That was a common complaint on the 2005 and older 545RFEs as there was no way to lock it into Drive (3rd). Tow/Haul only locked out 5th. 2006 and newer added the ability to lock out 4th as well. Other than that, I just hold it in the lower gear until it is not needed. I have driven for miles in 2nd, 4500 RPMs @ 55 MPH.
 

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if you have an 05 or older your probably never going to be happy with it. i tow loads similar to yours all the time and hardly ever have a problem with my 08 and 3.92 gears. if you have a big hill coming i just lock it in 3rd and in never drops more than a few mph with the hills we have around here in michigan. that feature was a huge improvement on the 06+ trucks.
 

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Yeah, I noticed that on my 05 as well. I tow a fairly large TT, and on slight inclines it likes to hunt between D and OD1. I tried to figure out how to lock it out of OD, but no success.

Does anyone know if any of the tuners have this ability? I have SCT and would love if this was a feature, but I doubt it is.
 

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Discussion Starter #13
mines an 08 i'll try the manuall downshift i just don't like havin the tranny shiftin all the time and not to mention its bad when i'd rather tow w/ my dads 02 6.0 chevy crew than a 08 ram and the only reason is this shifting i have more power torque and lower gear ratio than he does and his truck still pulls a lot smoother
 

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I have an 07 with a Hemi and 3:92s also. If you were to regear to 3:92's you would probably be much happier with your towing.
 

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Well like the other guys have said your tranny is keeping right in your highest torque area Right where it should be to tow . The only other option that I can think of would be a manual tranny.
 

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Discussion Starter #17
i think its a shift control/ tranny issue w/ all these trucks if a truck with less power and 3.73's can pull easier than a more powerful truck with 3.93's somethins off i shouldn't have to run down the road at 4000 rpms to pull the load i stated above
 

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i think its a shift control/ tranny issue w/ all these trucks...
You are correct. GM (and Ford) decided to actually try and have useable gear ratios in their transmissions which allow the engines to use their power more effectively. Chrysler decided to use a wide ratio three speed tranny (which was quite an advancement in the 1960s) and slap two close ratio overdrives on it. The result is it very difficult to keep the engine at the RPMs it needs to be at for towing. One gear up and you are lugging the engine. Downshift and the engine is screaming and accelerating.

The only option is to manually hold it in the lower gear and use your throttle to control the speed.

The six speed manual transmission gear ratios are much more beneficial to towing and lets the Hemi rise to its full potential. Search TwinStick's posts. He had an auto and now a six speed manual, both pulling the same trailer with a Hemi and he says it is night and day difference.

But, it is what it is....so far the 545RFE has been dependable for me, but it was not well thought out when designed for practical gear ratios.
 

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Discussion Starter #19
finally the answer i was looking for that makes perfect since i love my truck other than this i don't pull enough to change over this is only a twice a year trip otherwise its 2 quads on a small trailer pulls that just fine, but it was just the larger load and didn't know what i could do to fix it
 

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I tow a 7k TT. With the 3.92's I was all over the place, never stayed in gear, even on the flat. 4.56's fixed it completely. It shifts into high gear and stays there only down shifting when I hit the grades. I use cruise control every chance I get and I don't use a tuner. Best $600 I've ever spent.
 
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