I am looking for something to lower the rpms in the truck in my sig, going down the highway. Right now, I am doing 73 with 2300rpms and would like to have it around 16-1800 if possible. I do tow a goosneck stock trailer. What would you guys recommend?

I know the gv would be close to $4800 installed. Would it be possible to do one or other of the other two though? Or is their another idea to help me lower my rpms at higher speeds?

Thanks

 

you can swap in 3:42 or 3:73 gears for less $. or a gear venders the other two options don't exist for your size truck

 

Taller tires would be the cheapest route, the altering of gears and overdrives can get really expensive really fast.

 

+1 on tires. The GV site actually says not to tow much with it as it will eat the drive
line.

 

I've read that too. The torque from the Cummins will eat that thing alive. I wanted one until I started reading that. I would go 3.42's.

 

If I drop down to 3.42s with 295 or 305 tires, about what would my rpms be running at 75mph? How much will jumping from 3.7? to the 3.42s affect pulling/take off loaded?

Its to bad the gv isnt stronger, and requires less maintenance, because its would really be the way to go.

 

I have had the gear vendors for years behind 4 CTD's. I tow at least 25k per year. I have one on my '99 now with at least a hundred k on it. Keep the fluids changed and drive responsibly and it will last a long, long time. it will reduce your RPM's by about 400 up in the 2000 level. I drive mine with 3.55's and 265/75/16's at 65 mph at 1800rpm in 4th gear, to avoid a 5th gear problem. I am coming home from a trip from east tx to nevada and back. Never had to downshift going over the mountains, except on one grade I got blocked behind a semi and had to wait to go around,and there are a lot of them. I love'em. They fill the gaps in gear spacing for a 5spd or an auto. And they are easy to install and can be found on the used market for around 2k. It's the nose piece that adapts to different trannies that is expensive.I have one available for a 5spd direct mount.

 

whiskers, on the gv, can a person add a bigger pan to accommodate more oil so you could change it less? I hear good and bad about them, $4500 is a lot of money to spend for me.

Whats the 5th gear problem? On my 6speed, would I have to tow in 5over, or can a person tow in direct 6th? Are the problems only occuring while towing or with just normal driving?

 

They have a deep sump option, i just ordered one for my GV. Regular sump holds 28oz, deep sump holds 48oz.

Std VS Deep sump below

http://www.google.com/imgres?hl=en&b...:0&tx=89&ty=70

http://www.dieselpowermag.com/featur.../photo_08.html

 

The 5th gear problem he is talking about would probably be the 5th gear nut falling off and then losing 5th gear all together.

A taller tire will help to keep your rpms lower at highway speed but from a stop it is a bigger tire to get rotating. How much will it drop your rpms vs how much harder it will be getting the tires rolling I dont know and I am sure others will chime in with a better answer.

My vote is for a gear swap, how much towing and how heavy would determine what ratio would be recommended..

 

5th gear problem is only for the NV4500 5spd.

 

Right on the 5th gear problem only on the 5spd. On the 6spd you could tow in double overdrive in certain conditions. The biggest advantage is the gears in between gears that eliminates the gaps. I have actually an 8 spd trans with the GV and use them all when not towing. In double over I can drive 75 all day long at 1400 RPM's. Your 6spd 5th gear is the same as my 4th gear, 1:1 ratio. With the GV you would fill in the gap between 5 and 6 and tow in 6 or if you have enough juice, 6 over, or double overdrive. On the freeway at high speeds it shines. In the mountains towing I use 4th over and pull the rockies steady without downshifting almost always. I run a steady 65 though as trailer tires are not rated for more than that. And my fuel mileage is best at that spot or up to 70. I am using a Hypertech in stage 2. It puts me at around 300HP. With your 3:73's you can go up in tire size and do fine. But remember there is a point where your tire size will drop your MPG's . All things in moderation when towing.

 

Ubet, If you look around you can find a divorced unit. It is the least expensive front piece version. Look on my other post for a pic. Basically it requires cross mount piece which bolts to the frame. You can have your driveshafts adapted or new shafts made for around $250 each. Some trucks only reqiure one shaft to be made others need 2. Usually 12" to 14" for the front shaftto the GV unit and then one for the rear. I usually remove the carrier bearing on a two piece shaft model and have the two shafts modified. If you do any of your own work, do it in the driveway, no problem. The shafts are the only send out work needed.The wiring is really not complicated and the manuals are good. I see them for sale often for around 1500 to 2000. If you need to change adapters it is around 1200 but they will take your nose piece in trade. But the divorced unit can be moved to any truck if you need to later down the road.

 

It would be nice to have a Brownie but from what I understand they don't make one small enough to fit.

 

for the extra cooling, i ran a set of fast coolers on my old 04.5. added 2.5 additional quarts of oil for it.