Gear Vendors

[EF-5]

Will I have any problems using the Chevy NP208 adapter? It is a little long, but it is the same one that Gear Vendors has pictured with their NP208 kit. I did pick up my GV for $700 which I thought was a nice price. I'm just going to go ahead and bypass the computer, so I can't be forgetful.

I am still a little confused about the fixed/slip yoke situation. As long as I have the right coupler and adapter it should work right? Did I need the short adapter, or the longer one? I didn't realize there were to different ones.

I appreciate the response by the way, and appreciate the link!

 

[EF-5]

It looks like the adapter of the slip yoke is longer, and the fixed yoke is shorter. I apparently ordered the slip yoke adapter for the NP208. Is this the correct adapter?

 

[soule64]

I installed one on my M1008 and also had to do some tweaking. I used a brand new system and the computer sort of had a mind of its own. Sometimes it worked fine, sometimes not at all, sometimes always stayed in OD. I had the main DC power for the computer wired directly into the fusebox per the wiring diagram, but i think it was getting a surge or low voltage condition. If I shut the truck off and started again i would get a different condition. To cure, I put a rocker switch inline from the box to the computer. I have not had a problem since. I see you are not using a computer, but I figured I would just throw it out there...

 

[EF-5]

I appreciate that! I have read that if the GV unit computer receives a power voltage of less than 11 volts that the computer will scramble. A similar thing will happen if it receives more than 14.1 volts as well.

Did you use the longer, slip yoke adapter?

 

[DrJekl]

I don't think you will have issues. My concern using the slip yolk style adapter you have more length off the back of your t-case. It seems a mile long with the fixed yolk system. You may want to build a mount for the GV hanging off a slip yolk system if the original output shaft is used. There is a lot going on back there movement wise and you may put stress on the transfer case or back of the transmission.

 

[soule64]

I did use the longer slip yoke adapter and it does look like there is a lot of leverage on the transfer case due to the unsupported weight, but I get very little movement if I get under it and rock it back and forth. I was thinking about fabbing up some sort of support for the unit. No issues with vibration though.

 

[EF-5]

I see what you guys are saying. I will most likely fabricate a simple support bar as well. I might even do a skid plate while I'm at it lol.

I want to install a 4" lift as well, later down the road. Do you guys think there will be any issue with the drive shaft angle since it is being shortened quite a bit?

I'll post pictures of my GV unit once I get it all nice and clean.

It should only be about two more weeks before I can start the installation process.

 

[soule64]

I put a 2" shackle flip/spring lift in and there is more angle than normal, but not bad. I would wait to cut the driveshaft until you have the lift in, because the dimensions will change. Also, per the installation guide, the unit uses a specific GM synthetic fluid that is quite pricey - like $30 a quart if I remember...

 

[EF-5]

Good thing it's only one quart right? haha. I wasn't planning on putting the lift in until next winter, so by then I'll probably just get a drive shaft made for me.

 

[truck1]

I have a 4" lift on my 1028,new springs up front,shackle flip in the rear.I had no drive line issues after the lift.Then I installed a new GV unit complete with NP208 adapter,slip yoke,all supplied by GV.I shortened my drive shaft after the unit was installed.I had a bad vibration/noise on the test drive.I put 7/8th flat bar shims between the transfercase crossmember and frame rails.While I was at it also installed new TC crossmember bushings from ORD.This solved my drive line issues.No noise,no vibration.GV claims you dont need any support for their unit,but it is alot hanging off the TC crossmember.The overdrive itself is not that heavy.Drove from Marin to San Jose yesterday @ 70 mph taching 2310 RPM's according to the tiny tach.I recommend the computer and the rocker switches if you can afford it.I leave mine in manual mode and use the floor switch to engage manually.When your speed goes below 20 mph it disengages automatically wether in manual or automatic mode.I thought about going your route buying parts here and there,but when I totaled it up I only saved a few hundred bucks,so I went for the new unit from GV.2 year warranty and some peace of mind I guess for what it's worth.

 

[EF-5]

truck1, I appreciate the response. That's good to hear that there won't be any issues with the lift lol. I wish I could afford the computer and the switch. I will probably just bypass the computer until I get the money to by a new computer. I just have to remember to disengage the overdrive before reaching 18mph when slowing down, according to the Gear Vendor's installation guide, leaving it off in 4x4 and reverse. I'll engage overdrive just as I need it, mostly just highway use. I was fortunate to find what I needed for fairly good prices!

 

[EF-5]

Over the past couple of weeks I gathered all the parts that I needed for the Gear Vendor install. After a couple of hours of labor, removing the floor board to get the GV adapter to fit, shortening the driveshaft, wiring the toggle switches, and finally topping off the GV unit with Amsoil gear lube it was finally time for a test drive. We put the truck in drive and reverse several times and everything was working fine. We left the shop to get enough speed to engage the overdrive...

We were no more than half a mile away from the shop when the truck locked up, and the worst screeching noise came from underneath the truck. It ended up having to get towed back to the shop, and it has been in the transmission shop for about a week. The transmission shop discovered the problem, and quite frankly I feel like a complete idiot.

Apparently the GV adapter needs fluid in it. I greased the bearings like instructed, but no where did I see that the adapter needed fluid. I looked every where and all I could find is that some of the transmission fluid would work it's way into the adapter. We replaced the lost tranny fluid from the installation.

I'm wondering if we didn't let the truck run long enough, or move it around enough in order to fill the adapter up with tranny fluid. The adapter has a fill plug, so that should have lit a light a light bulb off in my face.

The adapter and coupler are completely fried, but I did get an amazing deal on a new adapter and coupler. I'm going to let the transmission shop do the next install even though the installation was quite easy. I just don't want to make a stupid simple mistake again. Pictures will come soon!

Any comments on that??? haha

 

[kenz5380]

I do stupid stuff like that pretty regularly, doesn't stop me from trying again though. I'm pretty excited to hear how this all works out as i would like to do the same to my 1008. Thanks for keeping the thread alive with updates. I'm really looking forward to the pictures.

 

[EF-5]

No problem! I'm going to get the pictures and a video up ASAP. Hopefully by the middle of next week the truck will be finished along with the videos and pictures.

 

[soule64]

Strange - I never put fluid in mine, nor did I read anything in the manual referencing it. I would assume (always a dangerous thing) that fluid would enter from the xfer case since the tail housing is removed. Also, mine has no drain plug - it does have a vent port with a brass hose fitting at 12 o'clock.

 

[EF-5]

I called gear vendors and no fluid is actually placed in the tail housing. The bearings and coupler are splash lubricated from the transfer case just as the original tail housing is. I topped off the transmission, but I did not top off the transfer case. GV informed that the transfer case should be topped off as well. Which makes complete sense, but I didn't make the connection.

The adapter is almost twice as long as the original tail housing, and I only put in enough fluid to make up for what I lost in the original tail housing. It would at least take double of what I lost to make up the extended area of the GV adapter. I just didn't check the fluid how I was supposed to. The transmission shop said my adapter was dry...lol. Expensive lesson no doubt.

 

[EF-5]

Alright time to update! The new adapter and coupler came and were installed! This time I knew what to expect and everything went smoothly. I tested the overdrive last week and it worked beautifully. I made a trip to Alabama and back with no problems, and was cruising in the far left lane the entire time.

I am still working on getting the video together, but while I'm waiting I'm going to film a walk around and drive video to show everyone how it works ASAP.

By the way the truck is for sale in the classified adds! It stands at $5700 right now. It's a great truck, but I am starting a new business in the next month or so!

 

[EF-5]

Gear Vendors installed under the truck with new driveshaft.

 

[kenz5380]

Did you end up having to fab a cross member for the gv unit? Does it feel steady enough just hanging off the back of the transfer case?

 

[soule64]

Did you end up having to fab a cross member for the gv unit? Does it feel steady enough just hanging off the back of the transfer case?

I was worried about that on mine, too. Until I can fab up a more permanent bracket, I made a temporary one out of 1/16" x 3/4" flat steel. I drilled the top and bolted it to one of the bed crossovers with enough room for adjustment. the bottom of the bracket is wide enough to run the rear seal clamp through. I tightened the top bolt just enough to take some of the movement and provide a little support. I was worried about having tension on the clamp, but so far it has worked great. no vibration whatsoever.