Teach me the ways of the Gear Vendors OD on my C6

[bookite03]

I bought my truck with the GV unit already installed behind the C6 and 6.9. This is my first experience running an aftermarket OD unit. I talked with the previous owner how he ran it, he said he just drove in Auto-Mode unless he was towing hills, then he usually manually controlled it with the foot switch.
I drive with a pretty soft foot to conserve fuel and reduce wear and tear as my truck is a daily driver. I've found in Auto-Mode the shifts in/out of overdrive are much firmer, also the truck will sometimes bounce in/out of OD if I hover around 45 mph and at times coasting on the hwy around 55-60.
I've resorted to running in Manual-Mode and shifting into overdrive at about 45-50 mph, anything under that I just leave it off. The shifts in/out in Manual-Mode are much smoother and the truck almost never drops itself out of overdrive unless I command it to. I dont mind this, but sometimes my wife drives the truck...and you guys kow how that goes .
I guess I'm just wondering if this is normal? Is there any calibration to these units to optimize operation? Any insight would be much appreciated.
Thanks

 

[mohavewolfpup]

Do you have the dash unit with a green and red light for the gear vendors? Mine only turns the light on for the right one. Never the left side. Burned bulb? Can't figure out how to take it apart and see the bulb!

 

[icanfixall]

Some just click it and forget it. I usually manually shift in and out of mine by the foot switch. You can take off in 1st, then at around 25 mph step on the floor switch and you will be in 1st over or as some call it 2nd under. either way your in gear and od. Then hand shift into 2nd but shift out of od. Do the same for 3rd. It takes timing and some prectice to make it smooth but its well worth it to have 6 forard gear on the C6. I have 8 gears on my E4OD.. Wnat even more gear choices. Do what RLDSL did and install a three speed spicer aux trans. Then you have 15 forard and three reverse gear. Never have a problem pulling any hill again.

 

[bookite03]

I have the rocker switch with both mode lights on it mounted under the dash...the right side Auto light only comes on in that mode. The left green Overdrive light comes on when its engaged in either Auto or Manual.

I've been told you can split all 3 forward gears with some timing and finesse. There's a benefit to gear selection when towing, but for as much "bob-tailing" as I do it seems unnecessary.

So far I guess everything I'm doing sounds normal for operation in my truck....

Another question, what maintenance is required on the unit? Is it pretty straight forward for a DIY? Any internal adjustments needed over time/wear?

 

[icanfixall]

Nothing to adjust but change oil at the prescribed times. For that please call Gear Vendors. They have a help desk thats able to answer any questions too. I found them very helpful.

 

[bookite03]

Will do, I appreciate the info!

 

[icanfixall]

Synthetic gear oil is used in these. Its a GM and Mopar product sold over the parts counter. Gear Vendors can tell you what the names are. I forgot but I got the GM oil.

 

[OLDBULL8]

Lost all my info on the GV. IIRC, never shift under 25 MPH and only lube with one quart. Is that correct?

 

[mohavewolfpup]

Lost all my info on the GV. IIRC, never shift under 25 MPH and only lube with one quart. Is that correct?

Maybe for a older one? Saw one you had to manually shift. Mine has a brain box so that isn't needed

 

[fellro86]

It is best if you do not engage it under 45 mph. The oil pump in the unit is driven by driveshaft speed, so slower = less oil flow. The manual recommends not engaging until 45. If you want a manual, simply contact GV and they will send one out to you. The way I ran the one I had was just to engage it like a regular overdrive, there isn't really that much benefit from splitting between the gears, although a C6 might see the benefits better than the 5 speed it was behind. Even when it was behind the A518, the splitting didn't do much.