The Advance Adaptors Ranger 27% OD gearsplitter two-speed box (that sandwiches between bellhousing and tranny) is on order. The '78 NP435/205 are in pieces in the garage, being refurbished. The proper hydraulic clutch bellhousing and hardware has been located, and we are negotiating.
But...
Offroad Design is coming out with 2:1 reduction box based on the NP203 range box which sandwiches in between tranny and T-case. Can you say "108:1 crawl ratio?"
Gear Vendors has an 23% OD planetary unit which replaces the T-case's tailshaft. Double overdrive with my 4.10s works out to a 2.34 final drive ratio, highway cruise around 1700 RPM or so.
Somebody stop me!
Eddie

 

You better make sure you still have room for a driveshaft......you can't connect the tranny to the rear....also, what rear will you be using? an 8.8 or 9" won't be strong enough with that crawl ration and lockers.....just a few thoughts...

 

There is also the doubler box, that mates a 205 and a 203 together for up to 3.98:1 low range..Or 2.00:1, or 1.98:1, the normal 203 and 205 low ranges.

 

I would not worry about the driveshaft, where are you going to put all the shift levers?

Roger Lane
Test Analyst
Sr. Automated Test Engineer
IBP, Inc.

 

I called Offroad Design yesterday by the way. ETA is 2 weeks on the Ford doubler kits being available. My 203 & spare 205 await...


1978 Ford F250 Supercab, Altered Wheelbase, Modified Skyjacker lift, D60s, Lockrights, 4.88s, 4WDB, 15/42x15 TSLs on 15x10 Arizona Wheel Chrome Wagon Wheels w/ R.B. Ent beadlocks, 351M/C6/205

 

OK, let's count levers:

1--Ranger Gear Splitter
1--NP 435
1--Doubler
1--NP 205
0--Gear Vendors (uses a push-pull ****)
---
4--Levers total. Shucks, taint nuthin', only one's bummed is my dog.

But wait! There's more! I can convert the 205 to Dual Stick operation!

1--Additional 205 lever
---
5--Levers total.

 

Whoa! there fella, slow down. If this truck is going to be driven on the street, you'l probably be very unhappy with it's driving habits. Remember that every time you feed torque through gear boxes such as these, your creating more relative friction. The larger rear you'll need to handle these contraptions will also cause more friction. All that friction will rob you of some of the torque that makes those gears usefull. And what about those drive shafts? All these items will add a good 35+ inches to your drivetrain, thus shortening and steepening your rear shaft. Don't forget your weak link rule either. After maket gearboxes aren't known for being bullet proof. If you beef up your drive lines and rears to handle the power of a 400ft/lb V8 with outrageous reduction/torque-multiplication, I'd hate to see a $1500 Ranger torque spliter become your weak link. When your finally finished, you'll most likely find that you appreciated the way it came from the factory. Let us know what you decide to do!!!

 

I had already decided, long before I put that first post up what the combo was going to be, and yeah, all those gearboxes piggybacked together were over five feet long...

It's going to be the 27% OD gearsplitter/ '78 NP235/NP205 combo. The cost of the Ranger 2-spd. and the tranny and T-case was reasonably close to a simple overhaul of the Mazda 5-spd. Granted, I've lost the close ratio gear of the five-speed, but I've gained a creeper gear and still have a close-ratio if I feel like rowing two levers.

I'm overhauling those two bulletproof pieces and mapping out the chassis on graph paper currently.

I ran a gear ratio spreadsheet the other day showing all those combinations. Shall we simply call it "mindboggling"?

Ed

 

Why not just get a 3- or 4-spedd T-case from a 2-1/2 ton? Mate that to an NV-5600 and you'll have a lot less hassles (IMHO)

 

Money.