Just got this coming https://m.summitracing.com/parts/POS-400

As mine is getting lazy and I always wanted 2wd low for backing up trailer. Does any one have one installed want to shear thoughts and pointers. I got it from summit as there are some China made out there. Hope I get the US made.

This is straight from Posilock site http://4x4posi-lok.com/genuine-4x4posi-lok.html

Edited March 14, 20178 yr by Dieselfuture

6 minutes ago, TFaoro said:

It would, but I'm trying to build something that actuates both directions. 

I got you. I am just trying to be simple to get 2 wheel low. Still want to ride in your truck one day. Hopefully I want be 85 and you have a 32nd gen with 16 wheel drive or whatever engineers are driving at the time.

4 minutes ago, dripley said:

I got you. I am just trying to be simple to get 2 wheel low. Still want to ride in your truck one day. Hopefully I want be 85 and you have a 32nd gen with 16 wheel drive or whatever engineers are driving at the time.

 I'll stick with old school trucks. 

Yeah if you follow that link it'll tell you exactly how to make a 2 wheel low kit!

I was looking at the link but I am on my 7th blue moon right now and the reading was to long. AAAAH HAAAA HA!

Sorry tfaoro. I misunderstood what you were after

6 minutes ago, Royal Squire said:

Sorry tfaoro. I misunderstood what you were after

No worries! I'll figure it out eventually. For now I have the cad locked into the "locked" position so I can shift on the fly. 

I installed a vacuum operated switch ( a GM heater / AC control from a wrecking yard) years ago.  The cost was $5.00 and it has worked for over 250,000 miles.  I think it is the best option because it allows for easy engagement and release of the CAD with vehicle slightly rolling.  I use the 2WD Low frequently and I believe this is an excellent upgrade.

 

If you go this route, just about any automotive HVAC control with vacuum ports and a rotary control knob will work.  You will need to figure out which ports will work for you - a vacuum pump with a gauge will be very helpful.  You will probably need to cap off some ports to make it work.  The end result is well worth the effort.

 

- John

Just want to update this, got my posilock put in and it was pretty easy aside from routing cable and figuring out adjustment. I did come out fire wall and under intake horn and over driver motor mount and then on top of axle to cad, like @Buzzinhalfdozen suggested, made sure had no drag in cable. It's a bit too long, but it works out after threading it in and out 20 times through slightly different routes to get it just right, I taped it up so end of cable didn't get all dirty. I guess it's longer than needed incase your truck is lifted or something. Mounted to the bottom of dash frame just to the left of 4x4 shifter and inline with firewall hole. I drilled it just to the right of go pedal, there was an indentation there and it was saying drill here its perfect spot. You have to cut away floor mating and under hood some noise matting. I didn't take any pictures under hood of cable as you couldn't really see it that good with all the other junk. So as for cable adjustment I found out that if you push red button in and pull it out about an inch it locks in place, same for pushing it in. But the whole knob also rotates and you can move that inch in and out buy rotating it. Well its not recommended to use it this way because you can do damage to it but what I found out is if you engage it in buy pulling the knob out you can then rotate it slightly counterclockwise till it dead ends and then you know it's fully engaged. Same for disengaging when you push knob in rotate it just a bit clockwise. It may sound confusing but if you ever get one it will make since. As for actual usage you have to make sure transfer case is engaged first before you go to pull on the knob, otherwise it grinds the collar. And disengagement is bit more tricky, seems to work better if you push knob in first to disengage cad then put tcase back in 2wd. Haven't tried stabbing brakes yet but I think it may help.

On 3/14/2017 at 5:49 PM, TFaoro said:

I personally dislike the looks of the kit. I'm working on finding some electric over air switches so I can have it engage when I want it to. 

 

 

 

You know, there are other options... 

 

You gotta go slightly custom, but the outcome is almost factory looking.

 

 

Edited April 30, 20177 yr by Cowboy

6 hours ago, Cowboy said:

 

You know, there are other options... 

 

You gotta go slightly custom, but the outcome is almost factory looking.

 

 

That's a bit too custom for me haha. I don't want to tear into an NP271 with no mileage on it!

When I find the right valves it'll be a piece of cake. If not, I'll just run vacuum lines into the cab and use "manual" switches. 

49 minutes ago, TFaoro said:

That's a bit too custom for me haha. I don't want to tear into an NP271 with no mileage on it!

When I find the right valves it'll be a piece of cake. If not, I'll just run vacuum lines into the cab and use "manual" switches. 

I'm currently tracking down what switch we installed on my uncles 99' for his CAD. It is a 2-way/3-port toggle switch. I'll post it when he remembers what the part number is. 

5 hours ago, BBHD said:

I'm currently tracking down what switch we installed on my uncles 99' for his CAD. It is a 2-way/3-port toggle switch. I'll post it when he remembers what the part number is. 

Definitely interested in what he has. I'm assuming it's something similar to the AFC live switch

The vacuum switch that comes with a BD exhaust brake would be perfect!  It's a 4-way direct acting servo controlled valve.  I had the number, but don't remember it now.  Either way, I was looking for a replacement and couldn't find anything.  Maybe you could contact them or pac-brake and see if they'll sell one to you.  

2 hours ago, Cowboy said:

The vacuum switch that comes with a BD exhaust brake would be perfect!  It's a 4-way direct acting servo controlled valve.  I had the number, but don't remember it now.  Either way, I was looking for a replacement and couldn't find anything.  Maybe you could contact them or pac-brake and see if they'll sell one to you.  

I'm trying to find a schematic for them and having zero luck. Any recommendations where to look? 

I think my dad has a BD or PacBrake on his 96, so I could try and find a part number on it. 

Ok came up with the part# MJTV-5. Manufacturer is  Clippard. 

I really like the concept.  My low stall T/C doesn't allow for rev up of the engine at all...so the low range would help a lot!! I hear that backing up a heavy load is hard on the automatic transmission. So the low range without 4x4 would be cool. Good for 16% roads too while pulling a trailer. 

Here are a couple pictures of the valve. Port #1 is supply, #2 and #4 are working ports. #3 and #5 are exhaust. I'll gather up fittings and get it installed on Monday hopefully. 

Looks a lot easier than doing the manual cable mod. Looks like a good article!!! Maybe we could sell a kit.

Edited May 20, 20177 yr by joecool911

Will this work to regulate vacuum?

No it's just a toggle valve. It only changes which port vacuum is directed to

On 5/1/2017 at 11:56 AM, TFaoro said:

I'm trying to find a schematic for them and having zero luck. Any recommendations where to look? 

I think my dad has a BD or PacBrake on his 96, so I could try and find a part number on it.