NP201 Twin Stick Question

[Wildergarten]

Those of you who have an NP201 know that the two sticks are interlocked such that the truck cannot be run in 2WD-Low. On our property, we have about equal lengths of paved and dirt roads, which require shifting out of 4WD to contine. Over the 30 years I've had my '69 with an NP205, I've found many an occasion on our roads where I am often carrying precarious loads of brush in back from one part of the property to another where it is safer to burn the pile. The bigger the load, the fewer the number of trips. So I prefered to go slow with a huge load in Low Range on dirt, and staying in Low Range even on the paved roads. To do that, I had to unlock the hubs, which is obviously a pain. With a single stick NP205, it's the only thing that works.

With a twin stick, one could conceivably allow them to bypass such that one could shift from 4WD-Low to 2WD-Low without having to unlock the hubs. It would seem that one could simply bend the sticks so that they could pass by each other. Are there any complications to doing that?

Thanks,

Mark

[PwrWgnDrvr]

U can also ask that question here:
www.dodgepowerwagon.com

[Wildergarten]

U can also ask that question here:
www.dodgepowerwagon.com

So I went there. Greg Coffin said he didn't think there was an interlock in the 201. So, I tried playing with the t-case shafts without the levers on it and found that he was right. The NP201 can do independent twin stick control; there is no internal interlock. To be able to run in 2WD-Low, all I have to do is bend the inside Hi-Lo lever to bypass the 2WD-N-4WD outside lever (there's no room atop the sheetmetal hump to move the outside lever outward), cut a wider slot in the trans hump for levers that can pass each other, and it will do it.

Kewel!

HOWEVER, if I do it, I don't want to do internal damage because I'm blowing off the linkage interlock. There is a specified gap between sticks in the FM (don't remember the specific combination) for what reason I don't recall. So I'll read up on what that's about in case I need to add some stops for the linkage. Hopefully there's room for that under the hump. I'll read up, report back, and if necessary add photos of what I had to do as this progresses.

[Wildergarten]

The factory manual says that the reason 2WD-Low is forbidden is that it can transmit excessive torque to the rear driveline and axle. I guess that means, "If you go there, don't stab it." It also means I'll be buying a tougher main driveshaft, including yokes, but that was in the plan anyway. From what I can tell, the only reason for linkage adjustments is to prevent contact with the body while assuring all possiblities of gear combinations are fully made. NBFD.

Mark

[PwrWgnDrvr]

4 lo would still transfer excessive torque to the rear if the hubs aren't locked.

[Wildergarten]

4 lo would still transfer excessive torque to the rear if the hubs aren't locked.

Obviously, and I've been doing it for 25 years. Still, with the rotating mass of a 383 I will take provisions in the driveline to mitigate that risk with bigger yokes and U-joints when it comes time to spend that $1500.

[LarryB]

You can leave the front hubs locked in or not when driving in 2WD.
You NEED the front hubs locked in when driving in 4WD.
If you plan to drive 10+ miles in 2WD, I would unlock the hubs. Otherwise, if you're just running short distances going from 2 to 4 to 2 to 4, etc, just leave the hubs locked.

[Wildergarten]

So I started bending my sticks to clear so as to allow 2WD-Low, which was a no-brainer. I kept the bend in the outside (passenger side) stick to about 1/4" and brought the inside stick in about 3/4" So this is mechanically functional, but we're not there yet. There isn't enough room yet for a twin stick boot. I'm wondering if anyone here has a preference.

The attachment 20190310_131344_001.jpg is no longer available

Bending it in such a way as to have room for a boot and bezel over BOTH the transfer case slot and the transmission looks VERY tight. One manufacturer (strongholdshiftboots.com) looks to make a very nice product. So I wrote him. He needs 1/2" between sticks. By the time one does that AND maintains factory clearances in the shifter slot, the slot becomes 2-1/2" wide. Given how close it is to the bend in the transmission hump toward the floor, one needs to open the slot more toward the inside. That quickly starts to encroach the space necessary for the transmission boot bezel.

The existing rear stick on one of my other trucks hits the back end of the slot. Is there an adjustment for this other than bending the bracket?
So I'm hoping some W-truck-wizard who has dealt with this one speaketh truth forsooth.

[Wildergarten]

Green truck stock twin stick setup.

I am so sick of the way this software can't seem to post the way the preview shows.
What the hell is this "image is no longer available" message?

[Wildergarten]

I'm still contemplating what to do about mice getting to the underside of the shifter boots too. I've contemplated brushes under the trans hump, stainless scrubbing sponges...

Any luck?

[justkris]

I put bounce dryer sheets everywhere when I park mine for 4 months. It seems to keep mice out of everything I put them in.

[swptln]

Mark,
I run mine in 4wd low all the time a lot for the same reason. But I don't understand the not wanting to unlock the hubs? it's a 2 second flip of the lever on the hub. I don't know most of the time when I decide to use the low range, the hubs are unlocked anyway, so I just engage into low and go.
Also, I wouldn't worry about your u-joints....if your running a NP201 you truck has all 1410 joints which are the big joints and far more stronger than the smaller 205 joints, which were 1310's and smaller.
The only thing you have to keep in mind with the 201's and 205's, is they're not like your newer chain drive transfers, so you can get some serious backlash pressure on and off the transfer and there is no give like a later chain style, but as long as your smooth on and off the throttle there fine.

[swptln]

U can also ask that question here:
www.dodgepowerwagon.com

So I went there. Greg Coffin said he didn't think there was an interlock in the 201. So, I tried playing with the t-case shafts without the levers on it and found that he was right. The NP201 can do independent twin stick control; there is no internal interlock. To be able to run in 2WD-Low, all I have to do is bend the inside Hi-Lo lever to bypass the 2WD-N-4WD outside lever (there's no room atop the sheetmetal hump to move the outside lever outward), cut a wider slot in the trans hump for levers that can pass each other, and it will do it.

Kewel!

HOWEVER, if I do it, I don't want to do internal damage because I'm blowing off the linkage interlock. There is a specified gap between sticks in the FM (don't remember the specific combination) for what reason I don't recall. So I'll read up on what that's about in case I need to add some stops for the linkage. Hopefully there's room for that under the hump. I'll read up, report back, and if necessary add photos of what I had to do as this progresses.

Mark,
the only stops or adjustments are on the levers and rods, nothing is internal. The bosses to keep the sticks from going past each other, is to give you a positive or to synchronize the disengagement and the neutral settings on the detents in the transfer, without the bosses and the correct adjustments there is nothing to synchronize the levers and detents in neutral and disengaged. Without the bosses you could possible have or put the transfer into partial engagement on the detents or the high/low lever could jump out of neutral. It's mostly for your neutral position. If that makes any sense..........I believe it was more of a safety thing if you were using a PTO. JMO

[Wildergarten]

the only stops or adjustments are on the levers and rods, nothing is internal.

Yup.

The bosses to keep the sticks from going past each other, is to give you a positive or to synchronize the disengagement and the neutral settings on the detents in the transfer, without the bosses and the correct adjustments there is nothing to synchronize the levers and detents in neutral and disengaged.

The levers are in the same plane. The bosses are for a gap adjustment as specified in the FM.

Without the bosses you could possible have or put the transfer into partial engagement on the detents or the high/low lever could jump out of neutral.

The FM says that the system is set up the way it is in order to protect the U-joints in the main driveline from excessive torque in 2WD-Low. That just seems flakey to me. The jackshaft gets the same toque in 2Wd-Low as it does in 4WD-low. So it's only the rear driveshaft they're talking about. In other words, I'll put better U-joints and yokes on the main driveshaft, which the driveline guys recommend anyway.

If I'm careful about the adjustment, I suspect there is no more hazard in the neutral than with the stock setup, but thanks for pointing that out, because I will be more cautious about it. I do use the PTO a lot for dumping as it is, so if I add winching to that usage, it will be important.

This conversion is important to me, because I do so much hauling on our property from dirt to pavement and back to dirt with huge and unsecured loads on my way from where I'm logging to where I'll dump and burn the tops. I'm going really slow doing this, not putting big loads on anything. So this setup will save a lot of time and rigamarole going on and off pavement 4 times per run. The key issue now is the end washer setup and clearance to the trans on the shift lever shaft. I'll be using a flathead allen with a toothed washer to increase the clearance. Got the stainless wave springs for the gap between the levers. Got new bronze bushings. Looks like I'll have to turn and part my own delrin slip washers. Just got a an old South Bend lathe for just that kind of thing.

Right now, I'm weeding 10 hours a day, seven days a week. We had a very wet May, so nothing is happening with the truck until late June. Thanks for the reply,

Mark

[swptln]

What kind of joints and flanges are they recommending over the 1410's ?

[Wildergarten]

What kind of joints and flanges are they recommending over the 1410's ?

I don't know the numbers because that one is a ways off. The guy said they have U-bolts instead of the formed straps, which does make sense.

[swptln]

That will mean you will have to change all three yokes, front and rear axle yoke's and the front output on the transfer.
All the others are u-bolts already.

[Wildergarten]

That will mean you will have to change all three yokes, front and rear axle yoke's and the front output on the transfer.
All the others are u-bolts already.

Yup. The front driveshaft will have to be made up custom anyway, as I'm putting in a (Ch3vy) Dana 60 that already has one for reasons discussed on my build thread.

BTW, welcome back to the forum, I've really appreciated your thoughtful posting.

[Wildergarten]

At long last, the twin-stick question is developing some answers.

Originally, the shaft was too short to allow sufficient gap between the two sticks to accommodate a boot. Stronghold told me they needed a half inch. I got most of it bending the shafts and the rest was by lengthening the shaft about an eighth inch building it up with MIG wire. The shaft was then filed back to concentricity and diameter. I had new bushings pressed in with about a .200 between the levers and another .050 on the outsides. The machinist honerd the bushing bores to fit.

Once the lathe was workable, I was able to make a jig bushing bored to fit over the shift lever shaft to guide a drill into the end of the shaft. Drilled it just over an inch deep and tapped it for a 3/8-16 thread. Then I sacrificed the bushing, making it into a thrust washer with a counterbore fitted to the bushing and a coutersink on the outside. The final analysis was to bore and part off a couple of nylon bushings to cover the bronze, effectively to pack the space around the shafts and bronze bushings with grease to keep out dirt.

I know this whole affair is getting close to the transmission but whatever clearance I'm going to need at that point will have to come out of the mounting bracket and trans hump sheetmetal. So overall, I'm guessing I'm about 1/2 to 2/3 of the way to having this worked out.

If anybody wants more photos I can do that for now.

[dodgeboykim]

I run a 2 Lo kit on my 96 Cummins Diesel 5 speed 3500. Its been in the truck for just over 20 years and haven't ripped anything apart yet with far more torque than a stock gas pot Sweptline Power Wagon. Just don't abuse it and you should be just fine.

And if you read any 4x4 type magazines etc a twin stick conversion to allow just 2 Lo is a popular conversion.