and yes, look around for a good used one on ebay, junk yards and craigslist.

 

I don't have any experience with one, but i've heard alot of good things about them.

I found a chart on there wedsite, explaining how it works and showing some RPM's drops and some examples.


They are expensive though!



I would like a manual shift brownie box before one of those though. But those are even harder to find!

 

The GV shifts like a two speed rear axle, you would have a button on the shifter to shift the GV. So it turns your 4spd to an 8spd, example you have 1st,1st over,2nd,2nd over,3rd,3rd over etc. They work better on a manual because you can completely cut power to the driveline eith the clutch. On an auto you let up on the pedal and it shifts (rather harshly). From what I hear on the auto's guys tend to leave then in overdrive when empty and direct when towing, they aren't a smooth splitter in an auto.

 

Incorrect. I have a GV behind my c-6 and it shifts great. If it shifts hard then the operator isn't shifting at the correct speed/rpm. And your not going to use it in 1st gear because your not turning the internal pump fast enough to have enough operating pressure to activate to planetary cone clutch. One thing to remember is to NEVER backup with a gear vendor activated or you will damage the clutch.
You can expect to drop about 500 rpm at highway speeds.

 

The GearVendor shifts fine, loaded or empty. You do not let off the throttle shift, if you do that is when you get a harsh BANG when it shifts.

87Crewduelly is correct, you don't use the gearvendor in 1st and likely not 2nd with 4:10 gears. If I remember right, GearVendor says around 25 mph for enough pressure for the unit to shift properly. I've run a GearVendor in my 86 for around 16 years.

 

Well thats good to here, just keep in mind thisis what I heard from a guy that had on behind a C-6 about 10years ago, so I knew nothing about them, still learning about them, so thanks for setting me strait.

 

Thanks for the responses guys. I've often thought about how much better off I'd be with my truck as a daily driver (i.e. cruising at highway speeds of 70mph +) if I just had one extra gear, so the idea of the GV is very appealing. While just shy of $3K is a lot to spend, if I do get a 25% fuel eco gain, at an average of 15,000miles per year, and a deisel price of $3.75, it would take about 4.5 years to pay off the investment, or 68,000 miles. While not superb, it's better then most of the payouts from a hybrid vehicle. Also, it should enable the rest of the drivetrain to last longer, so in the long term, it could be well worth it.

One final question, a Banks sidewinder turbo system is essentially the same price, and claims about equivalent fuel econ gains. It also should prolong the life of the engine with reduced egt. I know there are lots of folks familiar with this upgrade, so my question is, does it live up to it's claims.

Further more, how would it pair with a GV? I mean if the Banks adds 25% fuel eco gains by itself, and so does the GV by itself, what can be expected together? If I can get a 50% gain in fuel economy that essentially pays for itself in roughly 5 years, and prolongs the life of the truck, and makes it move liveable for daily driving, it's almost a no brainer.

Lastly, if you were to chose between one, which would you pick and why? Obviously the Turbo gives you increased power, but I would think the GV would be more daily driver friendly and better for those seaking more practical goals and performance.

FYI, my tires are whatever metric size converts to roughly 32.5 x 10.0, and that's as big as I can go without a lift, as they rub against the trailing arms up front right before I hit the steering lock.

 

IMHO the turbo is one of the best upgrades you can do, it really makes the motor come alive, will it get cruising mileage of the gearvendors probably not, will it make the truck fun to drive, tow better, quieter yes. The fuel ecomomy gains of the turbo com during accerleration and towing.

 

While I do use the truck for towing, it's on average two to three times a year, and usually relatively short distances, 100-200 miles. And while I certainly wouldn't mind the added horsepower and torque for just acceleration purposes, I find the truck's current acceleration tolerable, and I'm certainly used to it this way having driven it in the stock shape for almost 14 years now.

My main motivation for adding either of these upgrades would be to get the MPG's and just general highway driveability to improve enough for me to warrant using it as my daily driver, which is about a 45min highway commute one way, 5 days a week. 17MPG vs. the near 30MPG in our Outback that I am currently using is really no contest. The Outback is my wifes car in reality, and I'm trying to decide right now between getting a used commuter car, or just upgrading the truck to get close enough to what I'm looking for. Six grand of upgrades to the truck is really nothing compared to buying a whole other car for at least $8-10K, plus another car on the insurance, and then my truck isn't getting driven nearly as much and might start having more problems.

And, I've been trying to think if adding the Banks would actually reduce my RPM's at highway speeds? I'm not familiar with these types of upgrades, and never really thought about it, but would increasing the HP change the RPM at a set speed? I'm having trouble wrapping my head around that, without changing the gear ratios either in the tranny or rear end.