Gear Vendors Overdrive it is

[MarcusOReallyus]

It turned out to be a bad ground...

Bad grounds will do some very whacky things. When those little electrons start looking for a home, and the ground path just isn't looking very inviting, they go strange places and do strange things. Grounding is very misunderstood and often taken for granted.

...and the 4x4 lockout tapped into the wrong wire. ...

I thought about putting a test light on it before connecting it, but I didn't.

Oh, you are a bad boy! Report for flogging at Oh Dark Thirty!

 

[truck1]

Thank you Scottladdy!

 

[GPrez]

gPrez, did the GV guy Mike tell you what the unit is looking for on the 4WD circuit? Does it want to see 12 V relative to ground? Or ground relative to 12 v? The way that circuit is wired, the circuit runs through the light, down to the switch on the T Case through the white wire, back to a splice under the dash via the black wire, which then connects to that spider ground under the far left dash. The switch on the T case just completes the circuit to ground. Check Figure F4 in the -20.

We did not discuss what the 4x4 lockout circuit requires. I will play with it a little and see what happens.

The maiden voyage to the office today via highway and running between 65 & 70mph was very nice. The tiny tach was reading anywhere from 2450 to 2650rpm's depending on speed. I'm running 255x85x16 tires so my RPM's might be a little lower than someone running stock rubber. The one thing I did notice is that when the GV unit engages you feel it. It has a very positive jolt when it kicks in and also when it disengages as you come to a stop. I hope that is normal. I may call GV to be sure. I had also read where someone else on here installed one of these and they shimmed the transfer case to lesson the angle of the driveshaft to avoid a vibration they were feeling. I do not have that problem at all. I only have a 1" zero rate in the back so its not really lifted, but I also went with an aluminum driveshaft to lower the weight which will also help prevent that vibration from happening.

Below are the final pictures I took with the driveshaft installed and the controller mounted behind the glove box.

http://i1099.photobucket.com/albums...7B-8680-C6458D8DA88F-130-00000007FBD32B9A.jpg
http://i1099.photobucket.com/albums...6B-A859-249089800BCD-130-00000007F40081B0.jpg
http://i1099.photobucket.com/albums...0E-9F31-72D30AA88A81-130-000000054BE96B85.jpg

 

[truck1]

I have a 4 " ORD lift and had to shim my TC crossmember 7/8" downward to get proper driveline angle.I'm running 37" surplus Humvee radials and at 70 mph my Tinytach shows 2310 RPM'S with GV engaged. That to me is a huge improvement and much easier on the 6.2. I still have not figured out the lockout connection for the 4x4 when it is engaged.No biggie , I think it is an easy fix. I need to talk to GV and discuss the circuit. Not to worry mine engaged a little rough initially then smoothed out after the first oil change.Now I can barely notice it.When disengaging at say 45-50, try give it a little throttle as you manually click the floor button.That seems to smooth out disengagement. I discussed operation extensively with Dave at GV and that helped.Their manual of operation is a little vague in my opinion.

 

[Dave Kay]

We did not discuss what the 4x4 lockout circuit requires. I will play with it a little and see what happens.

I'm running 255x85x16 tires so my RPM's might be a little lower than someone running stock rubber.

I also went with an aluminum driveshaft to lower the weight which will also help prevent that vibration from happening.

Below are the final pictures I took with the driveshaft installed and the controller mounted behind the glove box.

Looks great! First impressions also awesome! Kick that bad boy into some gears and rough it up--- ya' got a big-time warranty!

(IMHO; better to know if it's a weak sister sooner than later)


Question(s) What are your tire's circumference? Stock 235/85x16's are about 32" and I'm planning to go 265/75x16's as they are also 32" but wider section, may go a bit taller if possible...

Was not aware that aluminum drive shafts helped prevent bad vibes... hmmm... is the cost a bunch more... or?

Wondered about your controller behind glove box, is there no info there one needs to monitor?

MUCHO SALIVATING HERE!

Good luck man and keep us posted... cheers!

 

[GPrez]

My tire circumference is 33.1".

The aluminum driveshaft reduces a lot of weight therefor it lessons the chance of vibrations considering the GV unit hangs off the back of the transfer case about 12" more than the original tail shaft alone. The aluminum one was probably about $50 more than steel.

There is nothing on the controller you need to monitor. There are a couple lights on it, but nothing you need to look at. There is a switch that you mount to your dash somewhere that allows you to switch between Manual & auto mode and has a red and green light which is the only thing you need to monitor if you like. There is also a foot switch you mount on the floor that you can press to turn the unit on and off.

 

[GPrez]

Truck1 is right on about the operating instructions. The install instructions are also somewhat vague. They leave a lot to be desired. Fortunately the install is fairly simple so the instructions not being the best doesn't hurt too bad. The customer service at GV is also very good so I would not hesitate to do this again on another vehicle. Hopefully the long term leaves me as happy as the short term.

 

[Dave Kay]

Thanks again Gprez, sure appreciate your taking time to post all this stuff.

I prolly could have PM-ed you for more details but figured it might be of interest to others, as well as getting the input from other GV owners, so maybe guys who are curious like I was, can see what's up with the GV units and maybe inspire another convert--- lol!

Otherwise, I'm definitely inspired and looking forward to getting mine installed ASAP (maybe this weekend?) and the info you shared was surely valuable... SOON!

Cheers!

 

[soule64]

I had a GV on my 1008 until i swapped in a 4L80. The only problem i had was that sometimes it would engage, sometimes not. I found out that the controller was sensitive to voltage fluctuations, and when the plugs would cycle, the 12v source would drop to 9-10v. I fixed it by putting a switch on the power source - as soon as the GPs cycled and the guage was in the green, I would flip it on. After that, it functioned great. Anyhow, just thought i would mention it in case you run into that problem.

 

[MarcusOReallyus]

I had a GV on my 1008 until i swapped in a 4L80. The only problem i had was that sometimes it would engage, sometimes not. I found out that the controller was sensitive to voltage fluctuations, and when the plugs would cycle, the 12v source would drop to 9-10v. I fixed it by putting a switch on the power source - as soon as the GPs cycled and the guage was in the green, I would flip it on. After that, it functioned great. Anyhow, just thought i would mention it in case you run into that problem.

Good info.

It would have been much simpler to put in a relay triggered by the GP relay, so that the overdrive was automatically disconnected when the GPs cycle. Then you never need to think about it.

 

[trooper632]

how much did the GV cost

 

[MarcusOReallyus]

Check the website. They run about 3 grand.

 

[scottladdy]

Any updates? I am just about to pull the trigger on a unit for my M1008A1.

Thanks ...

 

[GPrez]

Any updates? I am just about to pull the trigger on a unit for my M1008A1.

Thanks ...

I love it. It works great and I can cruise on the interstate at about 2600 rpm's without getting run over. I would do it again in a heartbeat. You will not be disappointed.

 

[MarcusOReallyus]

Mt. Airy? You're only about 90 minutes from me. If I ever get to where I think I can afford one, I think I might know where I can go to take a look at one!

 

[Dave Kay]

Hey guys, finally did my GV install and would like to do a post here on it but too much else happening right now that limits my time. In a nutshell: it works as advertised, only there were some install and operation issues that, due to other prior commitments, I've had to put aside for the time being. Mainly the electronics are troublesome, but I bypassed them completely and did what others suggested and just went with a manual switch for now... I will post more on the other issues later. Meanwhile, the ability to get up to freeway speeds with the M1008 is a welcome result; cruise 60-65mph @ 2300 to 2500 rpms and now using the truck for daily driver. More later...

 

[GPrez]

Mt. Airy? You're only about 90 minutes from me. If I ever get to where I think I can afford one, I think I might know where I can go to take a look at one!

Anytime. We can meet part way and you can take it for a spin and see how you like it.

 

[U1100L]

Anyone try GV in a M1031? how Tight is it with the P.T.O.?

 

[Dave Kay]

Anyone try GV in a M1031? how Tight is it with the P.T.O.?

Can you show some pics of 1031 underside for comparison? Maybe a dimension or two will help.

 

[usmcgunner]

Just ordered mine. I hadn't seen this thread until now when researching for the drive shaft. I'm debating on whether to have a trans shop do the install. I want to have the trans freshened up anyway, so it only made to sense to have them do it. But that's another 500 bones. Trans guy has experience with them and is actually the one who recommended it to me when I inquired if he could do a 700 swap, which he recommended against. He said he'd do it, but with my intended use, he wouldn't warranty the trans.

I hate to sound like I'm raining on your build, but one thing I'm doing different is a fixed yoke off the rear of the GV unit. Did they mention to you this was an option? In the jeep world (another hobby that makes empties my pockets) a slip yoke eliminator (SYE) is a common mod when lifting. I'll be replacing the drive shaft with that has an inline slip. Additionaly, I'll plan to have a CV at the GV unit. This removes any concerns of the slip yoke getting pulled out of the unit during articulation.