Should I install a Overdrive unit or not?

[JHawk]

I like my father's OD unit with 4:10 in a 3500 with 235 tires. But, it has it's drawbacks. You can hear a small gear whine that comes up through the shifter. It also seems to have more drivetrain backlash or slop.



I am converting my 2500 to a 3500 and have my choice of 3. 54 or 4:10. I know with the 4:10, it is low geared. I think with the 3. 54 and an overdrive it will be to high geared. But, what about a underdrive for more power with the 3. 54? I pull big heavy trailers often and need the power. I also take empty trips and like to drive 75-80MPH.



Question 1: What is the prefered over or underdrive unit out?

Question 2: Any thoughts on gear ratios?

Question 3: Any thoughts on over vs. underdrive?



Thanks.

 

[illflem]

Tuff questions

All I know is the gearboxes won't increase your mpgs.

Also moving this to products so you can get more response.

 

[GiesJ]

check this thread out:

https://www.turbodieselregister.com/forums/showthread.php?threadid=66682

 

[jpcnhear]

are you looking at a gear vendors

i have a 2500 99 with 4:10 and a gear vendors. It is one of the best investments I ever made. I noticed that you mentioned gear whine through the shifter hole. I have an automatic with four wheel drive, and have never noticed any whine. Of course i have a full banks system with the large muffler, and that tends to be louder than anyting else. I think the biggest advantage would be the fact that you can split gears for climbing with a load. If you have any other questions send me a line.

 

[JHawk]

Which unit seems to be better. GV or US??? Pros and cons???

 

[rweis]

I think the GV will NOT support an exhaust brake due to some sort of clutch system. I think the US Gear will support an exhaust brake.



I think the US Gear takes some getting use to for shifting. Can be done, but you need to really be part of the gear shifting sequence.



Bob Weis

 

[jpcnhear]

The gv will support an exhaust brake when not engaged. Meaning that while using the exhaust brake you use the gear ratio that is on the truck, not the gv ratio.

 

[Loren]

I've had a US Gear OD for about six months now. It's one of my favorite accessories.



I chose the USG over the Gear Vendors because I can use the USG in any gear and also with my exhaust brake. The GV won't work in reverse (no big deal), nor in first gear (also no big deal). The exhaust brake, however, was a big deal.



Overdrive vs. underdrive: If you want a gear lower than you have now, choose an underdrive. If you want a gear higher than you have now choose an overdrive. Except for the additional half-step gear at the top or bottom, all other gears are half-steps, so it doesn't matter whether you have an over or an underdrive.



The installation is not for wimps. If you question your ability to do an installation with minimal instruction (the supplied instructions stink), then you should have the unit installed by a professional.



These units are EXPENSIVE! Add the installation, if necessary, and you are talking some serious money.



They are mostly nice-to-have accessories, not requirements, especially with a six-speed. Whether it's worth the cost is up to you. (Naturally)



Summary: You will like it if you install one, but it will cost some big bucks.



Loren

 

[JHawk]

Thanks for all your replies. I have installed an US gear unit in my father's truck. It was an easy install. I just can't decide to use my 3. 55 without the OD or use another set of 4. 10 with. I reallize how much it cost and that is also a factor I am thinking about. I just don't like the scream of 4:10 without. And I don't like the big jump between 3-4 and 4-5 with the 3:55 and 5 speed.

I would really like to have the 6 speed with the 3:55 I think. The only thing, It would not give my a lower 1st.

 

[JNeiman]

I have a Gear Vendor for sale if you are interested. Its is two years old with low miles. Works perfectly. PM me or call me @ (518) 669-4426 if you have any questions or are interested. Thanks, Joe