2nd Gen Non-Engine/Transmission GV Overdrive Dropping Out

[JFitzgerald]

I just bought the truck in my sig with the GV already installed. The OD function works, but sometimes it just drops out for no apparent reason. The green light on the switch panel goes out at the same time, so I assume the control box is shutting it off. I checked out all the electrical connections, and fixed a bad one on the 4WD input wire. Still does it. Are there any troubleshooting functions in the control box with the LED display? I did get the paperwork for it with the truck, so I'll call GV, but I was curious if anyone else has had a similar problem?? The unit looks to be brand new, and the oil does too. It sure is sweet when it's working.

 

[RustyJC]

At what speed does it drop out? I understand that one characteristic of the GV unit is that it cannot be used under 25-30 MPH or so because the internal pump doesn't generate sufficient pressure to keep the unit energized.



Rusty

 

[JFitzgerald]

You're right on track. GV tells me it is designed to drop out below 18 mph. Mine is doing it even at 60 mph. The very helpful tech recommended checking the speed signal generator on the unit. There is also a "decimal point" on the display that indicates when the speed signal is good.



Only thing is that I'll lose most of the oil by removing it from the housing to check it, so I need to pick up some oil from the Dodge dealer first. He said it takes the same type as is used in the NV4500. Is there another source for this oil that won't cost me a limb? I angrily bought a Mopar filter for this truck the other day for $13! I'm used to paying about $6 for Fleetguards at the semi dealer, but they weren't open.

 

[kdcrockett]

Caution

Be careful about the lubricant you use in the GV unit. I'm at work so I don't have my GV instructions with me but I know it doesn't use any type of Chrysler lubricant. The GV unit uses a GM lubricant. I highlyt recommend you look in the GV manual. Do not use anything other than the recommended stuff. If you can't find the information, let me know. I'll try to remember to look at my book today (Sunday morning) and have the info with me this afternoon if you need it. Crockett

 

[JFitzgerald]

Thanks Crockett. The GV info I have listed part numbers from both GM and Mopar. It is supposed to be the oil that is used in NV4500's. The tech at GV said the same thing.



After getting ripped off for the filter at the Dodge dealer, I thought I'd try the Chevy dealer for the oil. It was over $20 per quart. The guy at the counter said "Sorry, the bottles are dusty". I said I wonder why?! :-{}

 

[JFitzgerald]

Finally got a chance to spend some time on the OD yesterday. It was the speed sensor input dropping out intermittently. After checking out the sensor, I determined the electronic control box was the problem, and decided to "toss" it. I hard wired the OD solenoid to work with the dash switch and the shifter switch. I also wired in the dash light. I think I can remember not to use the OD below 18 mph. I figure that control box would be expensive to replace and not really necessary for me. Probably more for warranty issue control and fool proofing. I can just turn off the dash switch if someone else happens to drive it.



Also changed the oil and cleaned the filters while I was under there. Can't wait to see how it helps my mpg.

 

[muchsnow]

At what speed? Units are designed to drop out at 15 mph, your speed sensor in the tail of the GV unit may be loosing it or you have fluid issue within the unit or solenoid is getting flakey(has to have good 12 volt wiring to it) Has the fluid been changed? GV has very specific req's for the fill, stick to them absolutely!!!

There's a screen filter in the unit somewhere also, I just don't remember where.

Call GV and have them send you all the lit as if you had just bought a new one. Once you get used to using the unit, they're great. Especially w/4:10 gears like mine. I have 60K on my unit. I'll never forget that diy install, it was easy, however.....comma... ... where I was stationed was not mod friendly... ... ..... and Louisanna wants to tax internet sales? shoot,. . don't penalize the consumer because ya can't provide locally... ... .