Hi,
I am looking to purchase a GV for my c6. I have found a p type that is just the unit and wiring (no c6 tail housing). If I can source a c6 tail-housing is there any reason why this unit wouldn't work? I know some are set up for a mechanical speedo cable and some are set up for an electronic.....are there any other things I should check to make sure it is compatible? Thanks

 

Personally, i wouldn't even entertain a GVOD purchase without the tailshaft housing. How much are they asking for the unit and wiring? Just to compare, I purchased my GVOD for my C6 from a junkyard for $250 which came with the unit, all wiring, and tailshaft housing. If he is asking for like $500 without a tailshaft housing, I'd say F him. If you go to car-parts.com and search for Gearvendor, eventually, you'll find a Type J or Type P for around $300. They are not ubiquitous, but I occasionally find them once a month just to compare prices.

You should call Gearvendor if you buy it, and order a seal kit. do the seals when you have the unit off. Also, buy shims from GV. I doubt your PO will remmeber to give them to you. Especially if he doesn't have tailshaft housing. Also, if the PO's truck is similar to yours, you might want to consider buying his driveshaft if the measurements are the same.

OH, before I forget, try to be the GVOD yoke. It's a GM yoke (i think 27 pin) and you'll need to match up your u-joint sizes accordingly. I had to buy a 1330-1350 conversion to make mine work. So if you can get that from the PO, you'll save some trouble.

I think I remember Maximum Overdrive selling a new C6 tailshaft housing for several hundred bucks and Gearvendor selling theirs for over a grand. I can't remember though, so don't take my word for it. I read when i was looking for GVOD's, that finding a used tailshaft housing was as rare as hen's teeth, since most junkyards don't know the GVOD is a package deal (tailshaft housing plus the unit). So they just trash the housing or leave it on the tranny, and I'm sure some sucker who buys the tranny will be extra confused on what the H happened to the end. Also, there is a heavy-duty metal cylinder that is used to splice the tailshaft to the GVOD shaft. If the tailshaft housing is missing, i doubt the cylinder is in the kit too since it was just held in by the compression of the tailshaft to the unit itself.

Also, just to confirm, you should make sure the wiring contains all of the following: 1.) the controller 2.) GV manual/automatic switch 3.) GV footpedal (but serously replace that stupid switch with a regular switch--a footpedal? what is this? the 1950's?) 4.) Speedohousing (if mechanical) 5.) speedocable cylinder (if mechanical) 6.) speedocable connector (has two wire leads that connect to the controller) 7.) speedocable extension cable
Also, make sure you aren't buying a 4x4 GVOD unless you have a 4x4, because that has different implications for the controller. Mine was a little off, so now i have a NC relay that I personally rigged up to shut off the controller and solenoid since my controller isn't perfectly setup for my van.

 

Thanks for the info. I will keep searching too. I was wanting to try and find a used p type with everything, but will always entertain other possibilities.

 

I second on the splined coupler. But i do have a tailhousing available in a month.

 

I sure as heck would love to know where to get a GV for under 1K! (5-speed for me) I've tried, and I can't find even the units for anywhere near $300... Often 1k for just the unit!

Heck, even without the tail housing would be fine; I can /make/ one if I have to.

 

Word......

 

They are out there. I just did a quick search and came up with a $199 prospect , maybe a $50 prospect, but i doubt a $50 GVOD would probably be good. Granted, they could be sold or garbage links, but this is how I found my $250 unit with the housing and all cables.

 

Why are you settled on the GV??

My DNE came from the JY for $50 (We pulled it, NMB2 bought it first, then I bought it from him for the same price)

Other than a hard shift, it works great and Holds everything I can make an A3K and 90cc pump throw at it so far...

My truck has actually gotten an average of 1 mpg less with DOD In mixed driving than with std gearing. I haven't had a chance to test the DOD out on a pure hwy drive yet, but I assume it might get marginally better MPG...

 

You know, i wouldn't be surprised if an OD was sold for $50, if they didn't know what they had. these units are not the kind of thing you see everyday, and since most vehicles nowadays have OD's stock, a lot of younger junkyard workers probably have never experienced an auxiliary overdrive. The yard I got my OD from really didn't know much about this "fangled gearvendor thing," and said they were just going to throw it on the scrap heap if no one bought it. The only reason why they even put it on the site, was because one of the yard guys saw the controller in the cab and thought they'd put the unit on the website just to see if anyone bites.

I just googled "gearvendor" on ebay and wow, those prices are crazy.

 

here's why....

US gear Overdrive out of production - TheDieselGarage.com
https://www.ford-trucks.com/forums/1...ive-units.html

 

That's funny, I had my motor and internal switch the same day from napa.

Anything else can be handled by getting bearings from a supplier... if you blow your gears up, well your screwed anyway, spend another $50 on another...

Bottom line, just gotta look around for deals... I wouldn't ever buy a GV box, but that's just me... GV gets by because its an easy name to spread in a limited market. Are they superior? Not a chance by any means...

 

Absolutely. But my main goal is not just quality, but accessibility. Google "gearvendor" and you get options. Google "US Gear/Nash" and the options are dwindling.

And as expensive as gearvendor is, their customer service is great and they do everything they can to help. They even went out of their way to help me, a guy who never bought their unit directly from them. All I've heard about US Gear is they ignore any support requests. And parts are nearly impossible to find.

 

GV wise, I have to be somewhat impressed with it's robustness... After accidentally frying my GVOD control unit, I hooked it directly up to the switch. No safeties, no nothing. Driven it like this for a couple of years now.

I have driven it in OD in reverse a couple of times. It... doesn't like it, to say the least. It's still working well, though, which says that it's decent build quality.
Same with leaving it in OD mode when slowing down, stopping and starting off again... GV specifically says not to run it in such low gears due to the torque, but my box is still there, so... Also, that, unlike in reverse, doesn't appear to harm it(aside from putting undue strain on the bearings/gears/clutches).

Anyway, the fact that it's stood up to /me/ means I have to give it some credit.

 

I have a low-tech way of fixing that problem. Find the wire that powers on your reverse lights. Run a lead from that reverse light wire to an NC Relay that opens the GVOD solenoid circuit if you put the vehicle in reverse. it's a simple solution and takes only a few minutes to install.

I've had that installed for a while now, and it's comforting to see my manual switch indicator light power off when I'm in reverse.

 

X2, The deciding factor behind my GV purchase was that it was already in the truck. I had no idea what it was when I bought it, the PO had to explain it to me. It is awkward and clunky to use, the red lever on the gear shifter rattles and drives me nuts. If there was another way to get the gearing I want I would ditch the GV in a New York minute. That said, it ~is robust... I had my spedo cable seize up and break, and while it was failing the GV unit went slamming in and out of overdrive doing 70 mph. Felt like I was being repeatedly rear ended by an 18 wheeler. GV didn't break, so yeah, it's stout. My experience with customer service was only about a C+. They were a bit rude, I never could get the owners manual PDF they promised to e-mail me, and I gave up trying to get prices out of them, just went ahead and ordered and let the bill be a nasty surprise. Like I said, I'd ditch it if I had another way to get a final drive ratio of about 2.50.