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Grinding 205 shift rails...

pvfjr

1/2 ton status
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Ok, so I've twin sticked two different 205's at this point, by only grinding one rail. There's two rails in it, which I've seen identified as the "mode rail" and the "range rail". Well I call that BS, cause it seems to me that it's more of a front output rail and a rear output rail. Anyway, I've ground the rear output rail, the one closest to the input of the transfercase (shown in pic below). Now all the old tech articles I originally saw only mentioned the two grinds in that rail. Doing this, I ended up with rear low, front low, 4 low, neutral, rear high, and 4 high, but I was not able to select front high. Is this because I only ground one rail? I just did another transfercase the other day the same as my first one, with the same results.
Lately though, I've seen some mention of grinding the other rail.

DSC00854a.sized.jpg

http://krazyk5.com/albums/Misc-Project-Pics/DSC00854a.sized.jpg
 
These are the ones in question. Why does the "before" rail appear to have less material than the "after" rail? How is this possible if you're grinding? I would think that the before and after titles had been switched around by accident, if it were not for the fact that the before rail appears to have a wear pattern on it. What gives? What purpose would this grind serve? Would this give me the front-high mode that I lack?

shiftrailmod_3.jpg
http://krazyk5.com/albums/Misc-Project-Pics/shiftrailmod_3.jpg
 
wow, damn good question... I dunno. Maybe Kyle at NWF can chime in...

j
 
if you look really close at the last pic you can see that material was removed, it is just at a slightly different angle. you can see the wear by the detent ball on the top but not on the bottom in this area, looks like when you grind down that spot it lets it slide that much further.
 
jekbrown said:
wow, damn good question... I dunno. Maybe Kyle at NWF can chime in...

j
Yeah, hopefully some of the people in the know will see this.
 
Jishory said:
if you look really close at the last pic you can see that material was removed, it is just at a slightly different angle. you can see the wear by the detent ball on the top but not on the bottom in this area, looks like when you grind down that spot it lets it slide that much further.
I think you're looking at it wrong. I thought that that's the way it was at first. It looked like they just ground out the slope of it on the right, and made it more abrubt.

When I looked closer, I noticed that the top rail is ground closer to the third shift detent than the bottom rail is.
 
I read this post about 11 oclock tonight(my time) and was ready to reply but thought how the hell am I going to explain properly without pics!

I guess you can call the range rail the rear output rail once the grinding is done.Looking at your picture it is missing the ramp,everything else looks good.I`m thinking that you may not have ground the flat long enough and plus not added the ramp.
I have ground about a hundred of them(no joke) since around 2001 all by hand and was like everyone else looking at pictures and trying to fiqure out how much to grind and where.The best way to understand it is to watch how it works thru the detents holes.

After reading this I went to the shop and ground one like your picture and I could get all positions like you said except front low,I added the ramp and got all positions.When the rails are all the way in its in low range,all the way out is high range.Its very easy to confuse this because of the shifter position vs rail position,that mag article link showing the shift knobs is wrong because they have hi and low backwards!

The front output rail does not need any work for a twinstick but I file one of the detent slots deeper so the ball snaps in place so your shifter doesnt float around in neutral or low range on some earlier rods.

IMG00001.jpg

IMG00003.jpg

IMG00008.jpg

IMG00006.jpg
 
Well the only pic of my rails is the very top one. The rest are just pictures coming from who knows where.

I know that the sticks reverse everything, as far as low being stick forward and rail all the way in, etc. Front high is definitely the one I'm not getting, as I drove it for a year this way and am very familiar with its operation. I'm thinking that maybe I didn't go far enough with the grind at the end of the rail. So if I'm looking at this right, the grind near the detents allows you to get front low and rear low, I think I screwed up the other one.

BTW, those pics are awesome. :bow: I think they should be inducted into jekbrown's massive 205 compilation. Very helpful. You have lifted the veil. I like knowing WHY I am doing what I'm doing, not just blindly following someone else's description. This makes it all really clear.

I wonder what was up with the whole before and after pic up there? There's no point to that thing. I don't know where that came from or what purpose it was supposed to serve. :dunno:
 
shift rails

Thanks for the pics, I am considering doing this as well. Do I need measurements to grind the shift rails or is all by eye? I have all the info. that JEK has, and it is helpful, just not sure where to grind. Any more info. would be helpful.
 
Well I guess you've got the pics with the digital calipers showing the dimensions of all the grinds then. Those didn't really do it for me apparently, as my end grind came up a little short. For the middle grind, just make sure that you give the interlock pin enough room so that it can be in the flat when it's lined up with the center detent. I've got to get back to the drawing board on the end grind.
 
rock on.... much "click-save" will be done. I may add a little text file to the twin-stick tech archive with info from this and other threads just to clarify things for people. Awesome work MEK/pvfjr!!

j
 
Here is a basic drawing of measurments for rail modification. I always suggest taking your time and going slightly less then the drawing, then check with just the detent pins and rails in and make sure everything clears. If not go a little more. You do not want to go to far or the case will be able to go in front high and rear low or the opposite which you do not want.

The excact numbers can change very slightly case to case and use these for a close estimate. Use your own judgment on exactly the grind needed on your case

TwinStickRail.gif



Jordan
NWF
 
Shift rails

Thanks JEK and NWF, went back and opened up the files you sent me and it is very clear now. What finish did you use on your shift rail JEK

And MEK
 
Finish? You confuse me. :confused:

I think I might just work on my rail while the TC is out of the truck. I can't be having a triple sticked doubler that isn't FULLY functional.
 
finish? I send the tech out... the pics in it aren't taken by me (mostly anyway) or showing mods I have done myself. I have taken apart several np205s, and swapped outputs etc... but I'm hardly a 205 guru. Thats one of the reasons I started collecting all the tech. ;)

My shift rails right now are still in the case, unmodified. They will be modded.... just haven't done it yet because I have a zillion other things on the list to do first. :thumb:

j
 
jaros44 said:
Thanks for the pics, I am considering doing this as well. Do I need measurements to grind the shift rails or is all by eye? I have all the info. that JEK has, and it is helpful, just not sure where to grind. Any more info. would be helpful.

Heres some more pics that may help,I lay them out with masking tape as a guide.I ruff them in with a cutoff wheel/die grinder and do the ramp with a burr/die grinder.

Also theres a picture of the 2 different front output rails,1 type has a shallow N slot and the other has a shallow L slot.Regardless which type I file it to the depth of the others otherwise you may have a harder time feeling the position.This may not be worth the work if you are not planning on disassembling your case

IMG00001.jpg

IMG00002.jpg

IMG00003.jpg

IMG00005.jpg

IMG00006.jpg
 
Now that's a lot of shift rails. I haven't seen one with the shallow detents like those. I think I'd want to even them out too. That'd annoy me.
 
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