CurleyMan
10-30-2010, 10:12 PM
I am now finishing My second NP 205 twin stick modification. I have learned a bunch through research and mistakes so it's time to share. There are actually two ways to permit the NP 205 shift rails to select gears independent of each other.
A. Remove the shuttle pins from the case (not the correct way to twin stick a 205). The shuttle pins move back and forward during any and all shifting of the transfer case levers. Grooves or slots in the two shift rails provide a combination of sorts that will lock out or lock in the shift rails depending where they are. The shuttle pins essentially guide the rails and make sure that 2wd, 4hi and 4lo are the only possible selections. By removing the Shuttle pins you will allow the 205 to be shifted into front high-rear low or front low-rear high. This combination of a high and low will easily break something in your driveline. I highly recommend against this method.
B. Remove and grind the rear output shift rail. This shift rail can always be found next to the input and will always control the rear wheel drive yoke. This twin stick fix will work everytime and has no negative effect on the operation or life span of your 205. The shift rail grind will always keep you or any friends from "crossing your sticks" front high-rear low or front low-rear high.
Here is my favorite write up!
http://www.pirate4x4.com/forum/showthread.php?t=572617
I have a few tips myself and reminders
ONLY grind one shift rail (input side)
If you take the second shift rail out- Take your time and move the first shift rail in and out while inserting the second shift rail. The shuttle pins will make it frustrating and will always influence your insertion and removal of the second rail.
Always try to maintain the position of your shift forks. When you knock the 3/16 dowel pin out of the rail and remove the rail try to leave the punch or allen key in the shift fork. If you don't the fork will fall out of place and it can be a PITA.
The original Flat strap bar that links your rails together is made of hardened tool steel. If you want to re-use metal this weld with the appropriate rod 7018 minimum and expect to sharpen and resharpen drill bits and to dull saw blades.
I prefer the flexible grinding disk (Gemini) made by Norton for the shift rail grind!
Test every possible shift pattern BEFORE you button everything up!
tools needed
punch set
grease
seals
grinding disk or hard wheel
flexible or long shaft magnet pick up tool
Shift rails have a 3/4' od so pipe with a 3/4"ID
Sharpie
ball peen hammer
wrenches and a 3/4" socket
A. Remove the shuttle pins from the case (not the correct way to twin stick a 205). The shuttle pins move back and forward during any and all shifting of the transfer case levers. Grooves or slots in the two shift rails provide a combination of sorts that will lock out or lock in the shift rails depending where they are. The shuttle pins essentially guide the rails and make sure that 2wd, 4hi and 4lo are the only possible selections. By removing the Shuttle pins you will allow the 205 to be shifted into front high-rear low or front low-rear high. This combination of a high and low will easily break something in your driveline. I highly recommend against this method.
B. Remove and grind the rear output shift rail. This shift rail can always be found next to the input and will always control the rear wheel drive yoke. This twin stick fix will work everytime and has no negative effect on the operation or life span of your 205. The shift rail grind will always keep you or any friends from "crossing your sticks" front high-rear low or front low-rear high.
Here is my favorite write up!
http://www.pirate4x4.com/forum/showthread.php?t=572617
I have a few tips myself and reminders
ONLY grind one shift rail (input side)
If you take the second shift rail out- Take your time and move the first shift rail in and out while inserting the second shift rail. The shuttle pins will make it frustrating and will always influence your insertion and removal of the second rail.
Always try to maintain the position of your shift forks. When you knock the 3/16 dowel pin out of the rail and remove the rail try to leave the punch or allen key in the shift fork. If you don't the fork will fall out of place and it can be a PITA.
The original Flat strap bar that links your rails together is made of hardened tool steel. If you want to re-use metal this weld with the appropriate rod 7018 minimum and expect to sharpen and resharpen drill bits and to dull saw blades.
I prefer the flexible grinding disk (Gemini) made by Norton for the shift rail grind!
Test every possible shift pattern BEFORE you button everything up!
tools needed
punch set
grease
seals
grinding disk or hard wheel
flexible or long shaft magnet pick up tool
Shift rails have a 3/4' od so pipe with a 3/4"ID
Sharpie
ball peen hammer
wrenches and a 3/4" socket