gear vendors OD

[SRehberg]

I just bought a 3500 with a Gear Vendor's OD unit installed. It gives a D/C part no. for oil or I can use Dexron II which they say causes a "firmer" shift. My question is three part; what type of oil are you using in the GV unit, and how do you like it? I find the instructions for shifting it a little confusing. If I want to upshift, say from 3rd to 3rd over, do you actuate the switch and this is all, or do you have to step on the clutch (5spd here) to allow it to engage? The instructions are very vague. Thanks

 

[TKingsbury]

I do not have one, but I've driven my friends truck with a GV. If you hit the switch, it will shift with or without the clutch as long as you are over 35 MPH (or whatever speed your controller is set to). I would use the clutch myself, without a torque converter it is VERY harsh (my friend demonstrated this to me :-laf ) If you use your clutch, you won't notice any difference between fluids. Just remember it will not work below 35mph, and do not compression brake with it engaged.

Travis. .

 

[PLaFrombois]

I would engage the clutch everytime. As far as the oil, I'm not sure if all models require the same oil. We use a GV in our Off-Road race truck, and we've had great results with the Series 2000 75W-90 from Amsoil. We'll be testing the new Severe Gear 75W-90 during the off season.



I'd give GV a call. Very good customer service.



Paul

 

[SRehberg]

Thanks for the replies; the oil is helpful to know. I contacted the GV people who were good enough to send me a owner's manual, but the oil recommended was a Chrysler part no.

 

[kscheffler]

Use the Mopar recommended oil it is synthetic and makes the GV shift smoother. Make sure you use the clutch when engaging the unit. My unit is ready for shifting at 22 mph. ANy speed below 40 push the switch on the GV and then engage the clutch. At the slower speeds it takes the GV some time to engage. I recently installed my unit for a 4k trip and increase my gas mileage by 2. 5 mpg at 78 mph I should be able to increase the mpg by 3. 5 when I slow down to 70 mph.

 

[SRehberg]

Thanks for the help on using the unit. I tried disengaging it while in gear using the clutch and it made a pretty good noise. Would it have been better to hit neutral, but then it defeats the whole purpose of having the unit. I see myself on the flat in OD with GV on, then hitting a small incline needing to drop GV out. What do you do in this situation? I think the manual says just push the button in but that creates a lot of noise etc. What am I doing wrong? Thanks

 

[bpenrod]

The synthetic lube will help smooth it out a bunch, I bought my fluid on line from Quad 4X4 instead of Chrysler. I also noticed it is a little harsher on the downshift. I sometimes pull the shifter into neutral then flip the switch and put it back in 5th. You wont even feel it then.

 

[SRehberg]

Thanks, I'll give it a try, as the other way it sounds like it would tear something up. It sure drops the rpm's for cruising, so hope it helps the mileage. I haven't had the truck long enough to know yet, thanks for the help.

 

[Jumbo Jet]

I had a GV OD and used it with a 5 speed and an auto. I always tried to synch the RPMs with the change - going up or down - with the 5 speed. When you get used to it, it will be smooth enough.



A friend of mine was driving my auto, accidentally down shifted the GV at about 75 mph. When I pulled the GV off the truck before I traded, it had a broken tooth I did not know about.



With the 2000 CTD - 5 speed - 4. 10 gears - at 80 mph from Grants NM to Oklahoma City, OK - empty - got 24. 5 mpg with OD on.

 

[SRehberg]

JumboJet, I'll try the rpm match, that would probably help a bunch rather than a idling engine and rev'd drivetrain. The mileage you got is great! I have 4. 10's as well, so there is hope in the mileage dept.

 

[kscheffler]

I have found that when dropping out of the over drive if I place the transmission in neutral and then let out the clutch overspeed the motor by 500 rpm and then push the clutch and the GV disengage switch that it down shifts quietly. Basically you just need to double clutch the unit.

 

[SRehberg]

I'll have to try these things as I have never had a GV unit before. I assumed it would shift in and out quietly, but that sure isn't the case. It will probably take a little getting use to. I'll have to anticipate hill climbs as it will take a bit going out of GV OD to straight gear, so a little momentum will be lost.