Gear Vendors O/D. Am I tearing up a what would normally be a dependable product?

[JJ Jackson]

Well I've had a string of bad luck with my GV O/D lately. First I broke the input shaft about 6 mos. ago, then today I fried the reverse clutches in it when I was backing up my trailer .



I know what you're thinking, "maybe its your transfer case or your clutch" but it only does it in 2whl drive reverse, If I put it in 4whl on the pavement the front wheels will help push the truck back and take the pressure off the rear driveline thus eliminating the slippage in the clutches. The GV O/D has clutches that work great forward but are not up to the challenge when pushing a trailer backwards up a hill.



It has been a good product, maybe 100k and a lot of towing off road have wore it out. Anyone else feeling the chatter in reverse?..... Jim

 

[Doubleclutch]

Have you checked the oil? Would expect it to be burnt from overheat to act that way. Any chunks in the bottom? You can always give GV a call at 800 999 9555.

Greg

 

[Headlight]

Why would you need the Gear Vendor unit to back up? I use mine to split foreward gears. The Gear Vendor is designed to work at a designated RPM. You can not get enough RPM for it to engage in reverse. My Gear Vendor will not engage in 4 x 4 as it has a by pass switch, will not work in 4 x 4.

This is my second GV unit. Had one in my 1992 Dodge Cummins 5 speed. Now have one in my 2000 Dodge Cummins 6 speed.

Great product never had any trouble with either unit.

 

[JJ Jackson]

Everyone needs to be able to split reverse and push there trailer backwards at 35mph. :-laf



No, just kidding. The GV O/D has clutches that work even when not in O/D.



It's not a direct gear to gear drive in forward or reverse, just look at the orange owners manual. There is also a revese test in the troubleshooting section to identify a bad reverse clutch. I realize now that I've been hard on it, I just was curious if anyone else was having the same luck with theirs.



Another aftermarket item I put on might also have contributed to its demise. The 2Low kit I purchased from BD. I believe that it threw to much torque to the rear wheels in low for the GV to handle.



When I broke the input shaft 6mos ago I should have just exchanged the unit at that time for a rebuilt one. Its $750 if anything goes wrong with the unit when it is out of warranty from GV. They make the individual parts so expensive that you almost have to buy the exchange unit.





I took someone advice and was able to back door an input shaft for $200 only to have this recent problem cost me another $750.



Live and learn. Hopefully everyone who owns the GV O/D will not max it out like I did... ... Jim

 

[DWitcher]

What exactly were you doing in 2low that would cause the GV to go out?

 

[JJ Jackson]

Backing a fifth wheel tight spaces, up a hill and on pavement. The 2 Low kit is designed for that reason so tou don't get that wheel hop and bind in 4 low.



I just was pushing a 35ft fifth wheel toyhauler fully loaded. It didn't break then, that was a year ago it slowly started to chatter in reverse, until I eventually could not use reverse at all, in low or high... ... . Jim

 

[4xquadrod]

My Gear Vendors went out in less then a year. It was due to backing up in reverse. I rarely tow with the truck so I not sure why it happend. Took it into Gear Vendors, they checked it out and installed a new one at no charge. Also, I was told that these units will work or not work based on the fluid level. Running out of fluid (So the tech guy told me) does not cause harm, it will simply stop working until you fill it again.

 

[Doubleclutch]

Running out of fluid (So the tech guy told me) does not cause harm, it will simply stop working until you fill it again.

Humph! If you're not careful, you can learn something every day. Sure sounds a little strange though...

Greg

 

[JJ Jackson]

Yeah, the first full size truck I bought had a GV O/D in it, but I never new it. I was always wondering what the red knob on the stick was for that did nothing when I pulled it.



One day I was changing the engine oil and decided to mess with the unit hanging off the back of the T-case. I noticed it had no oil in it so I put some regular gear oil in it and Wa-La..... overdrive when I pull the little red knob Oo. ... ... Jim

 

[TRCM]

I'm curious... the GV O/D units are supposed to be good for like 1400 hp or something like that. How can you break it backing up at a low speed (and thus low boost)??????

 

[DWitcher]

I'm curious... the GV O/D units are supposed to be good for like 1400 hp or something like that. How can you break it backing up at a low speed (and thus low boost)??????

This is exactly what I to know because I'm getting ready to install one in my 3500 tow rig.

 

[Doubleclutch]

DW- call them at the 800 number. They have a commercial cooler available.

I'm guessing it didn't like the 2lo back'em up. Lots of torque at low rpm, just like 5th gear doesn't like getting hammered at low rpm and high torque.

Greg

 

[JJ Jackson]

I'm curious... the GV O/D units are supposed to be good for like 1400 hp or something like that. How can you break it backing up at a low speed (and thus low boost)??????

Well, the clutches work really well in forward like you say, I've never had a problem there. But the clutches in reverse are somehow not up to the task.



I would probably put it this way, you know how you can push a sliding glass door open with your hand flat against the glass, well now pull it back standing in the same direction and without pivoting your hand to get better traction. It will work it just seems to slip more unless you physically adjust your hand to provide more friction.



I'm not sure, but I think the reverse clutch is actually the forward clutch being somehow used in the opposite direction in conjunction with some other parts... ... Don't quote me, Jim

 

[RAJohnson]

I have GV OD in my truck. :{ I broke mine when I was stuck in sand and was trying to rock it out with no weight in the back end. Well I got P'ed off so I hammered it in reverse, and she broke. It was hopping up and down and going from load to no load when it broke. I made it out by getting some wood and a couple of hours of my time. When I got home like you it would not back up in to the drive way so I had to put it in 4X4 to get her parked. I jerked her out and stripped her down. There was Aluminum every where and the clutch basket was broke. What there is in side is a bowl with clutch lining on each side. Not alot of moving parts in there Any way I ordered a replacement part and gasket kit from GV and rebuilt it. I had 5 people from GV call me to ask how I broke it, and ask if I was sending it in to get it rebuilt for a 1/4 of the new price. I told them I already ordered the parts and was going to do it myself. They said it is good for 1200HP in forward but not a lot in reverse. Any way it lasted another 35K before I lost it again because I did not get all the aluminum out of it when I cleaned it up. There are some passages in there with out the right tool you can not get to. I had worked it over in the parts washer for 3-4 hours when I cleaned it up. Any way that second time I sent it in to them and got a brand new one and she know has 105K on this one. And working good, Just have to remember not to hammer it in reverse, CTD has to much torque, or atleast more than it is built for.

 

[Jed]

oil change frequency

For those of you running the Gear vendors unit how often do you change the fluid and what kind of fluid do you use. Gear Vendors says every 10,000 and to use the mopar or gmc fluid for the nv4500 and not to use the (better) more expensive stuff from redline, royal purple ect... My unit has 22,000 on it with 2ea fluid changes both changes I dropped pan and cleaned both filters the high pressure filter was full of chips both times I cleaned it. Low presure filter was dirty but no big chips. Unit is a factory rebuild and seems to work as advertised. No towing just a lot of city and freeway driving.

 

[RAJohnson]

Try to change mine once a year. I called GV to check on what type of oil and they sayid to use the GM stuff. The book I got with mine when I got it back in 95 said to use ATF, but they have changed that now. I kepped mine when I went from my 95CTD to my 02CTD. FYI

 

[JJ Jackson]

Yeah, mines been in the sand quite a few times. Rocking it back and forth also.



I guess if I had known that the GV was weak in reverse I probably wouldn't have bought it.



Amost all my trips include off roading pulling a trailer and a camper, so merely not using reverse in adverse conditions is out of the question.



I guess I'll have to think twice about venturing out into loose terrain when I'm towing something heavy.



I broke a tranfer case a while back, I wonder if the slipping and grabbing effect of the failing reverse clutch pounded the T-Case gears. It sure makes a lot of banging when it slips, probably not good on the rear end either... ... Jim





Oh, BTW GV now recommends changing fluid every 5000 miles

 

[RAJohnson]

Yeah, mines been in the sand quite a few times. Rocking it back and forth also.



I guess if I had known that the GV was weak in reverse I probably wouldn't have bought it.



Oh, BTW GV now recommends changing fluid every 5000 miles

I would not worry to much about reverse as long as you don't do what I did and hammer it when the rear end is bouncing up and down going from load to no load. Thats what broke it. I now have 100K plus on it and I pull a 30' trailer(no problems)



I'm not going to change fluid every 5K miles!!! That would be more often then my engine oil, And I Love this truck and would not ever think of abusing it.