[dervari]

We were cruising down Hwy 19 in Middle Georgia today towing our clays cart and hit some hilly areas. There were a few hills that my truck downshifted on and hit about 4000-4200 RPMs until cresting, then would drop to 2700 and finally level off at around 2200. O/D was off and cruise was set around 65. Is this normal when towing in hilly areas?

Truck is an '02 Ram 1500 with a 4.7. Any comments appreciated.

 

[slammed1]

you need a gear........I put in H.O cams which helped with the areas you mentioned in my 4.7 but I recently installed 4.56 gears so now I can pull a lot more hills a little easier than before!!!!! The little V-8 needs a little torque to help aid in towing and a gear change would help a ton!!!

 

[dervari]

Ok...I'm new to the whole truck think..I was an SUV'er before. Where would be a good place to purchase the 4.56 gears? Is this just a simple (per-se) replacement inside the differential or more involved?

Thanks!

 

[HemiRoy]

That's perfectly normal with the Hemi or 4.7. Ours hits over 4200rpm in hilly areas when it needs it. Peak torque is at 4200rpm and peak hp is at 5500rpm. between those two rpm is the power band. Below 4200rpm your motor is just taking it easy. Above 4200rpm and it's simply in it's powerband. I wouldn't call it struggling unless you were over 5000rpm and losing speed. If you can get past the cringe factor of high rpm, our motors sound great at 4200rpm under load! I chose the 3.73 ratio for better mileage empty and the tranny can use second gear all it wants for the steeper hills. Yes I'll 900 lbs over but I won't be doing any launches from a stand still on a 12% grade in Arizona heat. Our truck tows our 10,040 lb 5th wheel with relative ease at 2600rpm. It'll tow in 4th O/D in tow/haul mode on the flats at 2000rpm and it'll downshift to second when it needs to and run 4200rpm and up. Not a problem!

 

[rockcrawler]

Mine does sort of the same thing, I have the Hemi with 3.92's. On those big hills pulling a 6k lb. car trailer it will down shift, on the bigger hills I turn the cruise off as I like to have a bit more control (in my mind anyway) and can run at 60-70mph, holding at @5k rpm, then back down once I get to the top. I always have the tow/haul on even if the trailer is empty.

 

[slammed1]

when I start towing more this summer I will let you know how the gears have changed the towing abilitys!!!

 

[dervari]

So as long as I keep the O/D off so it's not gear hunting, the surges to 4200 won't have any adverse affects on the engine or tranny, right?

I'm just towing a utility trailer with a clays cars...total of about 1400 lbs max.

Gotta love being a newbie at this..

 

[AIR_RAM]

YOU need gears! Your transmission is downshifting because it lacks the torque/leverage needed to hold that gear... so it needs to drop to a lower gear to get hte job done..... a set a 4.56's will put an end to that... and your fuel economey will be just as good if not better.... Mine got better going from the 3.55's to the 4.56's....and I can tow a house donw the street in OD!

SPEED SAFE, AIR RAM