whos running a doubler

[Towstrap]

was wondering what oil you are running in them have 203/205

[b454rat]

IIRC need to run 80 weight....Dont have one yet, but hopefully soon I'll be getting one...

[Mudder]

I have always used 10w40 in my 203 and never had any problems.

[msgross]

it matters if it's chain or gear driven right?

[Zoomad75]

Originally Posted by msgross

it matters if it's chain or gear driven right?

Yes, but a doubler 203/205 has no chain. It uses the bolt on rangebox from the 203 and the rear section that held the 203 chain is removed. What's left of the 203 is bolted to the front of the 205 via an adapter plate. ORD doesn't have the details of what fluid to use on thier website, but from what I remember reading, they don't make any major internal change (except for the shaft swapout in the kit) that would require anything different than what the two gearboxes were originally set up for.

[Blue_71]

and i have to be the idiot who ask-- whats the advantages of doing this?

[Towstrap]

Basically, the Doubler™ consists of the gearbox section from an NP203 transfer case coupled to a complete 205 transfer case. This gives you an additional low range gear of 2:1 plus your existing NP205 low gear of 2:1 for an overall low gear of 4:1. Adding lower transfer case gearing gives you huge improvements in off road control and torque without affecting your highway gear ratios(4.10's with 37-38" tires can work well). Adding a gearbox also allows you to run in your normal 2:1 reduction or in super low 4:1 reduction for best performance in any situation. Or not putting a real low gear into your axles

[Blue_71]

can it be done with a 205 and 208, or just a 205/203?

[vtblazer]

I run your basic 90w gear oil.

So far so good...

[Zoomad75]

Originally Posted by Blue_71

can it be done with a 205 and 208, or just a 205/203?

Most doubler's are based off of the 203/205 combo. Mainly because the range box can be unbolted from the 203 without much fuss. 208's and 241's have been tried, but since the case holding the chain in the t/case is the same that is holding the gears it's harder to separate. The one I have seen on the web took a 241 to mate to a 205. It took some major aluminum surgury to pull the 241 planetary set out and eliminate the chain portion.

203's are not the best t/cases in the world so they are cheap to almost free. So when you add the low cost to the fact that you can unbolt the "good" part of the 203 which is the cast iron range box, it's an easy choice to make a doubler out of it.

NWF makes a similer kit to the ORD Doubler, plus there are other options to get more gear reduction. A Klune-v underdrive or Black Box underdrive. Both add another gearbox to gain gear reduction.