I've been thinking about getting a 2-speed rear end for my '03 dodge. I'm thinking that maybe I'd get better fuel mileage but I really don't know anything about them. Y'all have any input? Thanks

I've been thinking about getting a 2-speed rear end for my '03 dodge. I'm thinking that maybe I'd get better fuel mileage but I really don't know anything about them. Y'all have any input? Thanks


IMO, you're better off getting and overdrive unit.

http://www.gearvendors.com/

Do you know anyone that owns one?

Gear venders OD I have heard is great. My friend in college, his father tows cars around the country with his 01 ctd and gets 22mpg towing 3 cars in the midwest at 80mph if I rember correct. But in an 03 dodge CTD, you should be getting at least 20 mpg unloaded. That is unless you dont have a CTD...

Did he install it himself?

Gear venders OD I have heard is great. My friend in college, his father tows cars around the country with his 01 ctd and gets 22mpg towing 3 cars in the midwest at 80mph if i rember correct.

I'm calling BS on the MPG claims......

The GearVendor's unit is nice but there are two drawbacks: 1. Payback on the unit is several hundred thousand miles assuming a reasonable 2-3mpg increase and 2-3mpg is higher than most of info I could find. 2. The GV does not work with an exhuast brake - you have to set it up to disable the exhaust brake if the GV is engaged or vice versa.

Brian

I never met the guy with it, but thats what Russ told me his dad said to him. We were at Wyotech togther for a year and a half. Russ's dad's last Dodge before he purchased that one had a few hundred thousand miles on it(I think he said 300,000 mile range). I thought he went from 16mpg to 21ish mph, so it was cost effective for him to buy one. But I dont know, second hand information.
As for no exhaust brake, its easy to wire in a kickout switch, just like my transmission has on in for the 4th gear overdrive.
No idea about install, second hand information again. Call the company. But are you really getting 22-28mpg like your sig says? If you are, you need to tell the rest of us how you are doing it lol.

Install on a GV looks pretty straight forward - you do need to shorten the rear drive shaft. GV bolts on in place of the tailshaft/output shaft.

My old '96 12V 5spd CTD 2500 4wd w/4.10s will get ~20mpg at best (my dad has the truck now) and my current '00 24V 6spd CTD 2500 4wd w/4.10s gets 17.5mpg at best. A 2wd CTD might squeek 21-22mpg but 22-28mpg is somebody in the marketing dept emptying the crack bowl.

Brian

but 22-28mpg is somebody in the marketing dept emptying the crack bowl.
Crack is good stuff! :smokin: Oh wait, Its meth out here I forgot! Damn I cant even keep up the drug of choice anymore.
Anyways Brain, how much does your 96 weight? My 93 with a low stall convertor get 16ish between here and work 35 minuates every day which is up and down and up hills and down and up etc..., But I am swapping in a 94 12v with a bunch of goodies into the limo in my sig in a month or two. It is going to weight about 9.5 to 10k when it is done, but up in the air a ways. I want to get 15ish mpg out of it unoaded going 60mph on flat freeways down to cali and back. I expect around 10 around here unloaded. I dont think another set of gears would help my situation though...

My guess is the '96 is ~7k and my '00 is ~7300 lbs. The '96 used to have 255/85R16s and now runs 245/75R19.5s (these are very heavy...) and my '00 runs 315/75R16s. Both trucks are used to tow 36ft 5th wheels weighing 13-15K loaded and get 10-12mpg while towing.

Brian

Mabye I should anticipate 8mpg... lol. Oh well thats the price of having fun:grinpimp:

are you really getting 22-28mpg like your sig says? If you are, you need to tell the rest of us how you are doing it lol.

Yeah, I am. That's mostly on flat ground though. I've moved since then to more hilly terrain. Just READ the "sig". It's all there. @70 I get 20mpg. @ 55-60 I get 28, I've even hit 29....once.
:)

I would not even consider putting a Gear Vendors overdrive in my truck. They are too light duty for a Cummins and they are too complex in the control unit (can't operate in reverse or 4wd without breaking). It sounds to me that you have reached the max fuel economy for that truck and if that is the cast it would never pay for itself.

If for some (money burning) reason you just had to have an over (or under) drive then I'd use a US Gear. Beefy unit, mounts between the trans and transfer case, does not care if it is going forward or backward, or if you are in 4wd, or using an exhaust brake.

Gear Vendor uses a sliding conical clutch that is hydraulically actuated (as long as the pickup screen is clear and the pump has not crapped out) to work thru a planetary gear set (like some automatic transmissions) including a sprag clutch that cannot be turned backwards.

US Gear is more like a manual transmission that is simply shifted by an electric motor.

This got pretty far off-topic pretty fast...

The issue with running a two-speed truck differential is generally gearing... unless you're running large tires, you may find the gear splits to be non-optimal.

Randii