Rear ratio?

[RSmoak]

Y'all are lots of help. I should've been coming here for reseach. The factory specs are great to know, but you all are serious.

Rear end ratio: 4.10 or 3.73? Pulling up grades and daily fuel economy, which do you reccomend?

Thanks,
Ralph

[RSmoak]

Y'all are lots of help. I should've been coming here for reseach. The factory specs are great to know, but you all are serious.

Rear end ratio: 4.10 or 3.73? Pulling up grades and daily fuel economy, which do you reccomend?

Thanks,
Ralph

[NCHornet1]

If you will be towing a lot in the mountains or at or near your TV limits then go with 4:10 if not the 3:73 should do fine and give a little bit better mpg on the highway, not much difference round town.

[TXiceman]

Assuming you are pulling with a diesel, I agree with the comments above. If a gasser and a larger trailer, go with the 4.10.

Ken

[RustyJC]

The package we ordered on our truck (Cummins HO, 6-speed and 4.10 axle) provided the maximum GCWR available from Dodge in 2002 - the 3.54 axle was 1,500 lbs lower in GCWR. The 4.10s are perfect for towing but rev the engine higher than one would want running empty in 6th gear (2350 RPM @ 70 MPH in 6th). The 3.54s run around 2000 RPM @ 70 MPH in 6th.

As others have said, if you need the additional GCWR, go for the 4.10s. Otherwise, the 3.73s will be fine, especially if you're looking at a Dodge with the new G56 transmission. 6th gear in the G56 is lower (higher numerically) than 6th gear in my NV5600, so the G56 will effectively lower your rear axle ratio versus the NV5600.

Rusty

[Jumbo Jet]

If you buy an automatic, the 4.10 would be a good choice.

I have an auto with 3.73. I typically like to tow at 65. The RPMs are just below the engines sweet spot at 65 mph. At 70 MPH with the auto, I am at about 1950 RPM. The Cummins with the Auto and 3.73 gears pulls my 10,000 lb. RV best at 1950 RPM.

[RSmoak]

A little more info:

I plan to buy an automatic in either Dodge or GM. Dodge overcame their HP/torque issues when the Cummins is mated to their automatic in 05. In the Ram 2500 the 4:10 does not raise the GCVWR, only in the 3500. I am limited to duals in the Ram 3500 for the 2006 year because I insist on having the long wheelbase. Since I'd rather avoid duals; if I go Dodge, I'm stuch with the 2500. Since the 4:10 won't increase the GCVWR, but will significantly decrease everyday hiway fuel economy (a 6mph difference at 1800rpm) and most of my driving is hiway I am concerned.

I don't believe I'll have the luxury of changing my mind after my purchase, so I really want to get it right when I order. You guys have the experience/wisdom in this area, which is why I ask for your input. I don't plan on pulling more than 12k in a 5er, but in a Ram 2500 I do anticipate reaching the GVWR with a full tank of fuel and the wife, kid, dogs, and cat onboard (plus ice chest, tools, firewood, etc).

More input please.

Thanks,
Ralph

[powerboatr]

4.30s
may turn a bit at 75, but it sure does give us much needed power in teh hills

[RustyJC]

Perhaps you don't want to hear it, but a 12,000 lb 5th wheel with 2,400 lbs pin weight is going to put you over the 2500's GVWR.

Rusty

[RSmoak]

That's pretty much what I was seeing. Depending on hitch weight, I might have to leave the family home, or try to go without fuel.

I guess in order to get additional payload capacity and single wheel 3500, I'll have to go GM. Really didn't want to leave a brand I know and love though.

My question still remains however, 4:10 or 3:73. What I'm reading is that if I go anywhere near mountains I'll really want the 4:10. Is that about right?

Thanks,
Ralph

[OCDUNE]

If you are looking at GM diesels, they only come in 3.73s from the factory, there is no option for a 4.10.

OCDUNE

[RustyJC]

With the 48RE automatic, which has a higher overdrive ratio than the G56 manual, I'd suggest the 4.10s.

Rusty

[K-Star]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by OCDUNE:
If you are looking at GM diesels, they only come in 3.73s from the factory, there is no option for a 4.10.

OCDUNE </div></BLOCKQUOTE>

That is why I traded my GMC 3500 for a Ford F-350 with the Tow Boss package. Came with 4:30 gears and plenty of towing capability. (BTW - The Tow Boss package on an F-350 SRW will provide the same weight capabilities as an F-350 Dually without the Tow Boss package.)

[powerboatr]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by K-Star:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by OCDUNE:
If you are looking at GM diesels, they only come in 3.73s from the factory, there is no option for a 4.10.

OCDUNE </div></BLOCKQUOTE>

That is why I traded my GMC 3500 for a Ford F-350 with the Tow Boss package. Came with 4:30 gears and plenty of towing capability. (BTW - The Tow Boss package on an F-350 SRW will provide the same weight capabilities as an F-350 Dually without the Tow Boss package.) </div></BLOCKQUOTE>

i am not sure what your saying, maybe the "tow command" and Tow boss" packages. they are tow completely different animals
but yes a 250 in a vew instances has a higher tow cap than a 350 dually, the 450/ 550 has a few overlaps as well.
but for 06
you can only get a tow boss package on a dually, reg cab, super cab or crew cab.
the reg cab 2wd max trailer wt for a fiver is 19,200 a 4wd is 18,700
the super cab 2wd
18,800, 4wd 18,300
Crew cab
2wd 18,600 4wd 18,100
all must be with dually option which is the only way right now ot get a 4.30 ls rear axle