View Full Version : overgear/undergear?

08-06-2007, 07:58 PM
anybody running any gearing modifications similar to the gearvenders set up on 1 ton or smaller trucks. i would like to hear how they effect fuel savings and milage as well as towing.

Gravel Rat
08-06-2007, 08:44 PM
It depends on what your after ? Taller top gear for highway travel ?

I think gear vendors are not a big thing anymore being most new trucks have enough gearing and overdrive. Its not like the older years where you have 3spd automatics and farmer 4spds the engine screams.

Keep in mind the cost to install the auxilary transmission will be expensive are you really going to save money in fuel.

Myself I would be looking at a underdrive box for lower gears for offroad uses. Say your manuevering a trailer around or you have a 1 ton dump thats maxed out first and reverse isn't always low enough.

08-06-2007, 08:52 PM
from what i am understanding about the gearvender set up is that you get both more gears in the lower range as well as a taller overdrive. for example is i have a 5 speed manual and convert to their system i would end up with gears similar to having a 2 speed rear end. reg 1st then 1st over to 2nd then 2nd over all the way through 5th. this would give me an additional overdrive as well. when running light wouldn't mess with it exept for the over 5th. might be a option for someone that needs to replace a tranny anyway. of course it will be more money but if it makes a diffrence in performance or engine longevity it may be worth it in the long run. especially if it can lower rpm's and save a little fuel. in the long run i don't think fuel will be getting any cheaper. many guys on here are running 1 ton dumps with a 460 gasser they might like to know of a way to save a little fuel in an otherwise great old truck.
good luck,

Gravel Rat
08-06-2007, 09:01 PM
The only engine I can see benefiting from a gear vendors would be a older truck with a 12 valve Cummins or a 7.3 IDI. With the newer trucks the ratios are pretty tight in the transmissions so the % of gear split you will get probably won't be much. I can see if you had a wide stepped transmission where a OD or a 3spd auto or 4spd auto.

Take a look at www.todaystrucking.com/decisioncenter.cfm?subsection=story&intDocID=17083&intDecisionCenterID=8

Its about class 8 trucks but it has some things that still apply to light trucks.

08-06-2007, 09:13 PM

here is a link for anyone that may be interested in this.