I recently picked up a new fifth wheel and after pulling it the first time I thought it would pull a little better than it did on small hills and overpasses (don't even want to get into milage:( ). My trailer empty is 10K and around 13K loaded. I realize this is a lot of weight and was curious if upping to 4:10's would help.

My truck is stock with around 6K miles. I am planning on a 4" exhaust and the A2/Juice when available.

TIA,
-Allen

I recently picked up a new fifth wheel and after pulling it the first time I thought it would pull a little better than it did on small hills and overpasses (don't even want to get into milage:( ). My trailer empty is 10K and around 13K loaded. I realize this is a lot of weight and was curious if upping to 4:10's would help.

My truck is stock with around 6K miles. I am planning on a 4" exhaust and the A2/Juice when available.

TIA,
-Allen

I keep hear people mention 4:10 rearend....has something changed? The last I knew the only ratio was 3:73??:confused:

I made an assumption that aftermarket/factory (gassers have 4:10) 4:10's were available. If they are not then I guess that answers my question.

Thanks,
-Allen

Put A Juice And *** In Youll Have More Power We Havent Towed Wiyh Oures Yet But Sure Goes Good Empty Waiting To Pull With It Probably In The Next Week Or So

Maxed - Keep in mind that if you have a 4wd (your sig doesn't specify) you'll have to change the front differential set as well..
Having said that, unless you in the hills constantly, I would think that 4:10 gears will make your milage worse on the flat terrain unless you run under 65.

Thanks for the responses.

My truck is 2wd and I do generally drive around 65 or so while pulling. I figured my mileage would drop slightly empty on the highway but increase loaded as the enigine doesn't have to work quite as hard. This has been the case with my previous gasser's so I figured it would apply to the diesel as well.

Thanks,
-Allen

Maxed,
I'm sure you could upgrade to 4.10s, but I'm thinkin' for the results and effort an aftermarket chip is probably gonna do as much for you without the hassle. The trick is to keep the truck in overdrive that's where the mileage comes from and with a chip the extra power will enable you to maintain overdrive for longer periods of time. This makes for better mileage and a quieter ride, it also helps to relax you when you are not jumping up to 32-3500 RPMs all the time because of downshifts. I know since I installed my Banks kit I rarely see a downshift......my trailer is only 9500lbs loaded but the Banks only adds about 70hp. Some of the other chips can add quite a bit more. Try that first before changing the drive train. My $.02 worth.
JP

Thanks JP, that was the direction I was leaning toward. I haven't had much luck finding someone locally who can setup a rear properly.

I'm going to order a 4" MBRP this week as a starting point. Hopefully Edge will have the A2 available in early August.

Thanks,
-Allen

Looked at the new 2006 chev. 3500 dually brochure at the dealer and guess what??? 6 speed ally and 4:10 gears!!!!!

Looked at the new 2006 chev. 3500 dually brochure at the dealer and guess what??? 6 speed ally and 4:10 gears!!!!!

Ha! GM what losers. They shoulda had that combo back in 2001....then I'd already have it. No way I'm gonna talk the misses into a new truck. Maybe, just maybe GM will design it to retrofit the earlier models....I can dream can't I? :rolleyes:
JP

I ran into a guy yesterday who was told when he bought his '05 DMax that you got 4:10 rear end when you got the HD Trailering Package. I brought him my sticker which shows 3:73 with the HD Package. So much for stealer hype.

He's got 17,000 miles, some with a lot of weight (23,000 behind the 5th hitch) and he's running pretty fast, usually at night. Has had no overheating problems, but any number of other smaller problems that are driving him crazy.

Ed

IMHO...I really don't think you'll see too much of a difference betwen the older DMax's with the 3.73 than you see with the 4:10's. I'd be willing to bet that if you look at the gear splits between the 2 Alli's, they equal out so that the DMax is still turning the same RPM in final drive with both trucks running side-by-side.

I believe the whole reason of going to a 6 speed is to keep the shift points closer to the peak torque range instead of the higher rev's up to 2800-3000 RPM during heavy load acceleration where the torque range has drastically fallen off.

But again...until I see some spec info, this is only my personal opinion.

IMHO...I really don't think you'll see too much of a difference betwen the older DMax's with the 3.73 than you see with the 4:10's. I'd be willing to bet that if you look at the gear splits between the 2 Alli's, they equal out so that the DMax is still turning the same RPM in final drive with both trucks running side-by-side.

I believe the whole reason of going to a 6 speed is to keep the shift points closer to the peak torque range instead of the higher rev's up to 2800-3000 RPM during heavy load acceleration where the torque range has drastically fallen off.

But again...until I see some spec info, this is only my personal opinion.

I hear what you are saying, but the early reports indicate an additional overdrive for 6th gear. If so, I bettin' that the splits wouldn't be any closer but the same. I personally hope that it is an xtra overdrive and that it will retrofit into the older models. With a chip and the xtra OD I could be knockin' down some mid-20's mpg wise (Dually).
JP

According to the ratios I read in the thread about the 6spd, if they both have the same size tires, a 6spd allison with 4.10's would be turning about 100 rpm less than a 5spd allison with 3.73 @ 70mph.

According to the ratios I read in the thread about the 6spd, if they both have the same size tires, a 6spd allison with 4.10's would be turning about 100 rpm less than a 5spd allison with 3.73 @ 70mph.

Well...that would almost prove my theory true then. The shift points are closer together resulting in quicker shifts staying near the peak of the Torque and HP band. Kewl!!! That will eliminate the high rev's and loss of MPG and power while accelerating.

I am on the road all the time and I love my bottom end power but I want lower RPM's on the highway...Could i go with a 3.55 rear and be ok?

What kind of drops in R's would i be looking at?

pro400exc...I've thought long and hard about that too. Here's why. 3500 dually's and 2500HD's come out of the factory with matching engines, trans, and rear gears. But the 2500HD's get LT 245 tires, the 3500 SRW's get LT265's tires, and the 3500 dually's get LT 215's.

So...essentially we have about a 3.93 rear gear because of the size of our tires and the RPM's the smaller tires force us to turn to run the same MPH as the single wheel HD's.

I have argued until I am blue in the face about why our warranties on the 3500 dually's would be voided by putting larger tires on our trucks because it would make us identically match the set-ups on the single wheel trucks. But it does, and I'm told dealerships cannot and will not reflash our computers for the larger tires.

So what you are asking, I truly believe is the only cure to get our trucks to turn the same RPM's as the single wheel trucks and nearly match their MPG. And I really don't think you will hurt a thing by doing it. If the single wheel trucks can have a bigger tire and the same towing capacity as us, why can't we either match them in tire size or go to a lower gear to match their RPM's? Because as far as I know we get the same ECM and PCM. So what you ask is a VERY good question!!!

But...this is just my really worthless $.02!!! Here ends this :rant: !