6 Spd towing - 3.73 or 4.10?

[corprimo]

We'll be ordering a SRW 3500 4 X 4 soon for towing our 11,000 pound 5th wheel. How low is 1st gear for starting off and maneuvering? I'd prefer the 3. 73 for better fuel mileage, but is 1st gear low enough with a heavy load?

 

[SnoKing]

We'll be ordering a SRW 3500 4 X 4 soon for towing our 11,000 pound 5th wheel. How low is 1st gear for starting off and maneuvering? I'd prefer the 3. 73 for better fuel mileage, but is 1st gear low enough with a heavy load?

I think it is 6 gear that you should be concerned with not 1st. The 6 speed has a lower OD ratio than the auto transmission and will turn more RPM on the freeway. 3:73 and 6 speed have to be a marriage from heaven.



SNOKING

 

[DCaswell]

Wish I had gotten the 3:73 instead & for really heavy stuff would motor along in 5th at 65mph & would get much better milage empty

 

[Casey Balvert]

I think it is 6 gear that you should be concerned with not 1st. The 6 speed has a lower OD ratio than the auto transmission and will turn more RPM on the freeway. 3:73 and 6 speed have to be a marriage from heaven.



SNOKING

The 3. 73 will handle an 11,000 pound fiver with no problem at all. Over 14,000 you should be looking at the 4. 10 for the increased towing capacity.



Casey

 

[Rickricket]

I have 5000 miles on a 3500 4x2 2004. 5 , 6 speed, and pulled my 18,000 lb 5th wheel from TX to OH. It has a 3. 73 rear end and I got 11. 6 miles per cal on the overhead. I could start the load in 1st gear without depresing the accelerator. Stayed in 6th gear in every state except MO. I thought I was getting a 4. 10 but when i looked at the description on the plates it is a 3. 73. I get 17. 6 miles (on o/h) in suburan driving so I am happy with what the 3. 73 does.

 

[klenger]

I tow a 10K 5er with 3. 73's and have no problem. If you were only going to use the truck for towing, get the 4. 10's, but if you plan to use it empty a lot, the 3. 73's work well.



Enjoy

 

[Joseph Donnelly]

If you are going to oversized tires and heavy towing, 4. 10 is better; otherwise, I'd pick 3. 73.

 

[mbaston]

100K plus towing up and down the Alaska Highway, 6 speed and 3. 73 have been perfect!

 

[Sherman]

Are you sure you want the SRW,if you are doing a lot of travelling to the lower 48 I would go with the DRW for safety's sake. Less chance of a blow out putting you into the bush on those gravel roads.

 

[Radshooter]

I second the vote for DRW. I towed a lot with an SRW before I got the dually (same trailer, same weight) and there is a world of difference in the stability. If DRW is feasible for you, give it some serious thought. I also tow with 3. 73s.



Steve

 

[FCecelin]

I have the 4:10 and it pulls very well , but I also use the truck a lot MT and the 3:73 would have worked out better. Of course I may change my mind if I go to a heavier fifth wheel . Jayco weighs 10400 with no fluids and minimal clothes and stuff. .

 

[RustyJC]

Our 3500 is used almost exclusively for towing our heavy 5th wheel, so I ordered it with the 4. 10's to get the extra 1500 lbs GCWR. Having said that, if you don't need the extra GCWR now or in the future (the next RV will almost always be bigger and heavier - ask me how I know! ), go with the 3. 73's - the 4. 10's are a pain running 70-75 MPH empty (2350-2500 RPM with 2nd generation LT235/85R-16E tires)!



Rusty

 

[Sarge]

A different point of view here. The place the 4. 10 really shines is pulling that load up a hill. My fiver is about 11500 camping ready, and we have some killer grades getting out of the left coast. I'm not a lead foot, especially when towing, so i',m really happy at 65 to 70 MPH. I know I pass LOTS of trucks on the uphill grades with no mods, and the 4. 10's. JMHO... ... ... . Sarge (And i'm eyeballin' that 36' fiver toybox for the Harley)

 

[corprimo]

Thanks for all the input - think I'll go 3. 73 ratios. My main concern was starting out with a load and maneuvering in campgrounds in first gear without heating up the clutch too much. Doesn't seem like that's a problem for anyone. The new Getrag 6 speeds coming out next year are geared lower in first gear to help with that sort of thing, but I'd rather order a truck now and still get the NV transmission. As for highway speeds, the 3. 73 should give better fuel mileage, and if a hill gets steep, I can always gear down. The broader power band and 6 speed transmission will be great compared to my 12 valve with auto. and 3. 54's - just not enough gears to choose from and not usable RPM's!



Dan Heynen

Anchorage

 

[NIsaacs]

You made a good choice with the 3. 73's. I like to gear fast (mph), run slow (rpm) with the Cummins. I think the ultimate ratio would be 3. 00 with a 6-spd direct trans. Overdrive is the weak link in all transmissions. Direct will last forever and puts out more power to the ground. 1st gear will start a load no problem. If you get in a bind with slow manuvering, you have 4-low to help.





"NICK"

 

[klenger]

... and if a hill gets steep, I can always gear down. The broader power band and 6 speed transmission will be great compared to my 12 valve with auto. and 3. 54's - just not enough gears to choose from and not usable RPM's!

You nailed it.



IMHO, climbing hills is not a problem with either ratio. Depending of the grade of the hill, any axle ratio will require you to downshift at one time or another. Sometimes 3. 73 will have the advantage over 4. 10's on a hill because you will have a higher speed in 5th gear. It all depends on your weight, grade, and even other traffic around you.



What's really important to me in selecting the axle ratio is how does it tow your load at cruising speed on the freeway in 6th (or whatever final) gear. If you are geared too high (i. e 3. 54), it is difficult to maintan power cruising down the highway w/o downshifting. With the power of the new 600's, the 3. 73's pull a 10K load w/o any trouble.



I was just messing with some numbers for (what I think would be) a great commuter/towing combo truck. Axle ratio of about 3. 07, and a 6 speed with a 5th gear ratio of 1. 0 and a 6th gear ratio of 0. 86 (instead of the NV5600 0. 73). In 5th gear you could tow all day long at 64 MPG @ 2100 RPM, and driving empty you would be at 75 MPH @ 2100 RPM. Maybe drop the 1st gear ratio a bit lower for better launches.

 

[tschwab]

I have 5000 miles on a 3500 4x2 2004. 5 , 6 speed, and pulled my 18,000 lb 5th wheel from TX to OH.

You do know your overloaded with towing that heavey of a 5th wheel? I believe the GCVWR on a 3500 2WD w/3. 73 is 21K. If your truck weighs 7K+ and your 5th wheel is 18K, your easily 4K overloaded.



Yes, the mighty Cummins will tow it, but your illeagle. Read this:



http://www.glamisdunes.com/invision/index.php?showtopic=24262his:

 

[NIsaacs]

KLENGER, those are some good numbers, maybe even keep the . 073 overdrive ratio for even lower empty rpm's. For some of us this would work great, however for the most part I think everyone would still "put'er in the big hole" and lose the advatage of the direct for towing. With a direct drive trans. , you force them to use direct. All this talk makes me want a 10-spd :{





"NICK"

 

[corprimo]

I just wish I could put in a 2 - Low switch on the '05 like I have on my '97. It really comes in handy! I hear that is not a possibility with the newer front axles...

 

[mconstable]

I agonized over the choice, and am glad I got 3. 73's, I don't like to go too fast while towing, though, so it works out well, I'm in 5th a lot of the time.

What really makes me feel stoopid is how long it took me to try 4-wheel Low to back in troublesome spots at a crawl!!

My clutch says... DUH!!