I have the 6.7 auto with the 3.73 and pull my 11K fifth wheel about 8 times a year. My question is that when I ordered my truck I thought about getting the 4.10 but with only towing a small part of my daily driving I thought the 3.73 made more sense. I have towed with my new truck from Texas to Yellowstone and Grand Tetons and have pulled through the big tunnel on I70 out side of Denver (forget the name) and over Raton Pass with no problems at all. It seems with the 6 speed auto it makes up some of the difference from the 3.73 to the 4.10 am I right? I will be stepping up to a larger 5th wheel in the future maybe as much as 15K and am wandering if the 3.73 will work with that kind of weight? I know the tow ratings are a little higher with the 4.10 but am not concerned with that. It just seems that 90% of the folks on this and other forums say to get the 4.10 instead of the 3.73 and if you look at the GM they only offer the 3.73 and some of them tow very heavy 5th wheels. I have a very limited knowledge of the workings of diesel engines and transmissions so your help would be thankful.

 

I tote around 20k with 373s. I here 410s is like night and day and only 300rpms more. TELL ME IF IM WRONG PEOPLE ON THAT?!?! Im considering 410's or 43?s with a gear swap possibly in near future but i do mostly highway travel. Im gonna boost my low end more tell help my tranny life out longer. Every gear ratio you get lower, increases your gvwr by 2000 pounds. TELL ME IF IM WRONG WITH THAT PEOPLE!?!?! Gear swaps can be done for 500-600 bucks including parts!!!!!!

 

Your signature line doesn't tell us if you have a single rear wheel truck or duallie? If you have the SRW I don't think 4.10's are an option.

If it were me, I would test drive a lot of 4.10 equipped trucks before I went to the expense of changing them out. Especially if you have a 4x4, it's going to cost a lot more than $500-$600 and it will reduce your mpg.

 

Thats true, And yes I meant 500-600 an axle so it can cost between 1000-1200 for 4x4's. Only reason I didnt get 4.10 on mine was cause of a 3,000 dollar price difference for same truck, but different gears. But I would of got 4.10's since I tote around alot. 3.73's are still plentifuly though of up to around 17k pounds. Also, if you plan on getting bigger tires, Do go FOR SURE with the 4.10's!!!!!

 

If you enjoy driving highway speed limits, or more, while non towing most of the time throughout the non vacation days, the 4.10 will raise your engine
300 rpm or more which would probably put more wear and tear on your motor than the 3.73. at the same highway speeds.
If you want to factor that into your decision.
And to reiterate the lower mpg as mentioned. I hope all that makes sense.

You may visit the hauling and towing forum and get some feedback from those folks.

Probably the perfect situation for the 4.10s is if one uses his truck
for just towing, in mountainous terrain, and doesn't worry about
mpg and wear and tear on his motor. What are odds in that.

jerry

 

I would go with the 3.73's. The 6spd auto's have double OD's so you can easily drop down to 5th or 4th gear while towing.

MikeyB

 

CCoop, is the 20K you mentioned the truck and trailer or just the trailer and how does it do in the mountains? When I ordered my truck it was a $50 option for the 4.10's but did not think I needed them. Mikey, down shifting to a lower gear is it the same as having the 4.10? While I was towing in the mountains in Colorado and some in Wyoming I never felt like I needed anything else it towed great but if I step up into a trailer that weighs about 15K instead of 11K is it going to make a difference? Thanks

 

My trailer weighs in at 7000 pounds and fully loaded with 3/4 cars i cant hit 20-23000 pounds without the truck so my gvcr is around 24000-29000 when im fully loaded. I have not done anything in the mountains yet and I wanna stay outta the mountains. Unless I bring my jeep!!!!! The gears is a 50 dollar option from factory but dealerships can price vehicles different and for some reason, the ram with 410 was 3 grand more expensive, same options, but silver too. Very weird, but thats why i got the 373s. I have no problem pullin, motor is more then enough. But if you dont care about the extraa 300 rpms, or 1 mpg less, get the 410s.

 

I just brought home a new 2008 with 4.10, will leave on the 31st for a 10,000 mile work trip (oregon to NH, down to Florida back thru georgia, Tx, Co etc. I tow a 14ft enclosed at about 5500 lbs, I also have 14000 lb fifth that I will take hunting in October. I traded a 2006 quad 5.9 cab diesel, 3.73 rear. which had modded transmission, intake and exhaust, lift pump, and quad std chip. I tow 30k - 40k per year, I will have a real comprehensive report and opinion by the end of october if this thread is still alive, or i will start a new one at that time. I personally belive that if you tow all the time like i do that the 4.10 with the two overdrives in the 68rfe is the ticket. I hand calc mileage all the time and will be able to tell if this is a good combo or not, I also think 3.73 will cost you mileage and unecessary wear and tear (low rpms) if like me, you always tow something. I run empty less than 5% of the year.

 

I ordered my truck with 4:10's and have had no regrets. I've pulled a 14k# gooseneck trailer from Salt Lake to Albuquerque (hwy 6 thru price, very steep grades) and at 70mph I was at running 2000 rpm. MPG was ~10 with the loaded trailer and 14'ish with the empty trailer (4k#). On the flats, running at 75mph, it didn't seem to be over stressing the engine, it actually seemed to be in it's zone! I plan on bumping the tire size up to 35" so the 4:10's were required to keep the gear ratio in the 3:70 range. But regardless, a stock truck with 4:10's runs really well, unless you want to run past 80mph!

Dan

 

I hit my break in period on friday, so I hooked up the TT and hit the road. I also have 4:10's in stock form. The difference I really noticed over the 3:73's in my 05' vs. 4:10's in my 07' was off the line and my TT Weighs 10K. Rolls off the line like nothings there..

I also live in the Salt Lake area and found out that I couldn't really exceed 65 mph up Parleys canyon, no matter what I did.

Being the trucks still new, I didn't really like it when it kicked up to just below redline, so It backed it off. But honestly, i'm not sure if I would have kept my foot in it rather it would have exceeded that speed or not. Time will tell as it beaks in I guess.

Now, on flat ground, I feel like I could have gone as fast as I wanted. I averaged just over 12 mpg on the overhead. 10 going up and 12 coming back but didn't clear it in between the two.

 

Yes, 4.10 is an option on the SRW, I did the paperwork on one until the lot boy filled it up with GAS and drove it about 4 miles...now I have a 3.73 which was the only other diesel they had on the lot.

 

I had 30 miles on mine when I drove it home from the dealer. I cleared the overhead half the way home and averaged 17mpg and some change. Fluke or no fluke? other than that it's been 13's with a mix of town and freeway.

My 5.9 3:73 with 35's , 15 mpg mix and 17ish on the freeway and towing my 10K TT it would average 15mpg.

I bought my 4:10's because I wanted larger tires and knew it would be in the 3:70 range after I was done. Thats really the reason people buy 4:10's to begin with....correct me if I'm wrong

 

two reasons, bigger tires for the younger set and towing heavy for the people that work their trucks, did the math and observed driving that the 6 speed auto with 4.10's is the same final ratio as my 2006 4 speed with 3.73, if you do more commuting than towing definitely go with the 3.73

 

either way, being that I have drivin my truck a little bit, I kinda wished i opted for the 4.10's. the 3.73's are still strong enough to pull, i would just like the 4.10's to keep me always in a higher rev. I will be changing mine out to 4.10's at 50,000 miles. I will be pulling tranny out too to see how she is behaving inside of her, cant wiat!!!
P.S. even with no load, 4.10s would be nicer just to keep me out of luggin. Even though she is really not with that nice motor. But just a nice crisper feel of the pedal if you know what i mean!! I dont care about the 1 mpg loss.. IMHO