I have a 8600 pound fifthwheel I intend to use to move my self back to Alaska. For some of those who drove threw Yukons mountains they are quite steep. When loaded I hope to have added my care behind, alont with my mechanic tools an other worldly possetions. I'm looking for an Gear Splitter to increase my towing abilaty. I've found Gear Vendor and US Dual Gear to have there issues that doesn't make me really want to spend the $3K on them. Does any one know of any other Under/Overdrive that will work like a normal unit such as what they use on a big rig diesel. The two listed abover ether won't let you down shift with the splitter on, or back up with out breaking if you aren't in 4x4, also I've heard that using an exhaust break is not advised. If these unist were truly rated for 30K-35K pounds they would have no issue with this being I always down shift my transmission rated fo 18K pounds. If any one out there knows of an other brand preferably one that mounts behind my transfercase, or knows of any unit available I would be most greatful for the information.

P.S. I'm operating a 99 Dodge 5.9 diesel with the NV4500 4x4 I believe a NP214 transfercase.

Also would any one know what gvwr my transfercase would be rated for???

Thanks

 

I don't know of another brand but I have had some experience with Gear Vendors. They won't take the 30 to 35K that they say they will. They are very nice when you are buying but you don't want to talk to customer service. They were the worst that I have ever dealt with. It takes a lot of miles to recover the cost and mine didn't make it. They wouldn't sell me a repair manual, said that I couldn't fix it myself. Have a friend who had a U. S. Gear and he had similar problems. They couldn't even provide a replacement for his. I have seen a used unit that was mounted in the driveshaft that had an under, direct, and overdrive but don't know who made it.

 

I don't have the gear vendor od personally, but I tried to but it off a buddy a few years back, he told me he would not sell it to me as I would be mad at him. He is towing near twice what you are and does not think that highly of it.

with that said, I tow about 12,500lb equipment trailer with my truck, I would spend my money on a 65hp chip, edge ez, van aaken, smarty....and that will be plenty to get you over the worst of it. I have not been up the alcan in the last 7 years but have before and the downer on an OD is if you need to grab 4WD and are in OD you are hosed. I had to grab 4WD a few times on the steep gravel hills......something to consider.

I hope you are taking a spare lift pump with you.

 

If someone had more info on what units were available I would be interested also. To me the perfect set up would be 20% under, 1:1 and 25% over. The under would be great for getting a heavy load going, or city traffic or giving you that acceleration advantage. The extra overdrive could be used to let the transmission's OD cool while you used the slightly less 25%. Then OD and OD when running empty. Is there anyone here who knows big rigs inside out? Maybe a "brownie box" or similar is just way too heavy, I don't know. I do know it would be bullet proof!

A US Gear underdrive with a Gear Vendor overdrive theoretically would work but cost and compatibility are the main issues with these two units. Mainly cost.

 

try lookin at a eaton fuller 6 speed that they put on the med. duty stuff they may have option for something like that but i dont know if they have any 4x4 app.

 

That might be too big of a tranny to use. And the starters are generally on the right side, from what I've seen. But if those issues can be solved, the 4x4 issue could be solved by going to a divorsed NP205 transfercase set up like in some of the old Fords. Of course you'd have a reletively high 4-low ratio.

 

Way too heavy. I'm not even sure they would even be bullet proof as some of these guys are putting out more torque than those old diesels did. There were smaller ones built but they would not even be close to adequate for these rigs.

 

Is there any particular model number or is Eaton 6 speed the main term? Do you know where I can find trans ratios?

Russ Roth, you did surprise me with the info about these Dodge trucks producing enough torque to break auxiliary splitters. What do these transmissions and auxiliary splitters weigh just out of curiosity?

 

I couldn't tell you what they weigh but they are quite large. Considerably more bulk than a standard 6 speed trans. The smaller ones are not very big, at least the ones I have seen. They date back into the 50's and maybe before.

The torque #'s I was talking about are not stock.

 

Hi Speedtred,

The US gear is the unit that would work for you....IT CAN be used to split ALL gears, is strong in reverse , can be used in 4wd AND allows the use of an exhaust brake....

Several of the short cummings you mentioned were ONLY for the Gear Vendors model...

The only short coming of the US gear model in my opinon are the possible extra whine of the gears (I read that possibility in another post somewhere) and the fact that it takes a little more difficulty installing since on a 4x4 it goes before the transfer case (but the advantage is you CAN use 4x4!).

I haven't gotten one yet but in all my readings I believe I will end up with the US Gear model on my truck.

Hope this helps you,

Andrew

 

I havent looked into them for years now, but I remember a unit called Michem or Michel. Spelling isn't right. It was a box you mount in front of rear axle. It would give you 2 different gear ratio's. You had to choose before taking off. You could order it with whatever gears you wanted. Say 327 ratio for highway and fuel econ and 455 for towin in steep hills. Down side to me was you couldn't use 4x4 and you couldn't switch while moving. And it didn't give you more gears per say, you still had 4 gears not 8 or whatever while on the move.

 

If you want more info on a transmission swap option, search "eaton transmission". Here's one of the links buried in those threads. http://www.sanco-bg.com/Conversion_NV5600.htm

 

First of all You wont need anything other than what your truck has to pull you and your worldly things up here, Trust me your truck as is is more than adequate for what your gonna be doing those yukon Mtns are not that bad. take your time use a lower gear if you have to and enjoy the trip you wont belive the trucks and such that come up here with the loads they pull, you should see me.LOL from what you discribe of our truck its got what you need. Sure it would be nice to have the extra but its not needed..just my 2 cents.

 

Well said!
I'd put my money into some Mach 1.6 injectors and a Smarty...... and keep the change!

RJ