Posi-Lok system
 

Hey everyone. Has anyone ever put in a Posi-Lok system before? How easy is it? Does it really require drilling (I do not have a drill and only basic hand tools, so I want to avoid that if possible)? Will installing it cause the front differential to lose fluid while taking it apart? I was looking at this: http://tal4x4.com/prod-purchase?kid=1421&gid=-1
so I can eliminate the actuator and vac hoses to eliminate the possibility of a vacuum problem when I least expect it. I already had the nasty surprise of getting the car with a broken shift fork and GMC charged $1200 to fix it and half-fix the harsh transmission shifting (in other words, replace the pressure solenoid and not reseat the PCM connector that caused the problem while also keeping the car for 2 weeks). The TCCM fried itself 2 weeks after that! Another $600. I realize that the electronic problems cannot be prevented with Posi-Lok since it only controls the front axle, but I realize that that is the most likely failure point and the most expensive to fix. If the TCCM fails again, I can go to a salvage yard or eBay. If the encoder fails, I can go to RockAuto. Both are alot cheaper then another front axle rebuild. I am using the 4WD on average twice a day nowadays, so I do not need it getting stuck in or out of 4WD. I appreciate any advice on this. I want to make this 4WD system more reliable and stop it from sticking in 4HI for a few seconds after shifting into 2HI.

Do you have the three-button (2HI 4HI 4LO) system? I know there are two types of posiloks so make sure to get the newer redesigned one. I don't know the differences between them though. (the first link below has a comparison as well as instructions) There have also been several people who converted the transfer case so its manually shifted like the older Blazers. It's also possible to lock the actuator cable so the front diff stays engaged and you only need to shift the tcase. (wouldn't need the posilok then but you wouldn't have the 2LO that the posilok adds)

Here's a bunch of links with some good info. There's a ton of info on this forum and even more on zr2usa.

http://www.zr2usa.com/mboard/index.php?showtopic=7213 posilok info

http://www.zr2usa.com/mboard/index.php?showtopic=45582 locked diff engagement

https://blazerforum.com/forum/steering-suspension-drivetrain-36/converting-4x4-manual-shift-51420/ my thread regarding this topic

http://www.zr2usa.com/mboard/index.php?showtopic=11695 manual nv233 tcase conversion

https://blazerforum.com/forum/builds-48/german-98-blazer-build-45501/ starting at post #80 more info on manual tcase

https://blazerforum.com/forum/article-submissions-discussions-47/how-ghetto-electric-manual-4x4-discussion-thread-50508/ even more info on manual tcase

http://www.napaonline.com/Search/Det...104_0282389423 I have also heard of people using a cable similar to this one instead of the posilok. way cheaper than the ~$200 kit


Sorry I don't have much firsthand advice, I haven't converted anything yet but I'm planning on it soon so I've been bookmarking tons of good websites that deal with this. Hope that helps :P

Thank you for the good advice and links. Yes I do have the 3 button setup with an actuator under the battery (Didn't the Autotrac setup not show up until 1999?). I am sure that this is a newer designed one that goes directly to the differential. If I do get it and it is the old one, I will exchange it because I want to eliminate as many failure points as possible because I do not want to spend money at GMC replacing expensive stuff like the shift fork (again) or actuator.

I did consider making my own kit, but I would like to stick with something that is proven to work and easy enough to install. I just want to keep it simple and install a proven kit and not go to extremes like lock the cable permanently. It still binds up if the transfer case is unlocked and the axle is still locked (It did stick a couple times and take longer to disengage. It went into 2HI on the switch, but it was still binding on turns until it unlocked.). I would like to add 2LO in case I have to pull something on dry pavement to protect the transmission and transfer case. I can't convert this transfer case to a manual shift (believe me, I would love to do that and eliminate the electronics. Kind of ironic because I am an IT Network Administration student and I am around computers for 80% of the day and the TCCM is the only computer that I hate.) because I have a center console with a floor shifter (not to mention a Windows XP computer in the console, touchscreen next to it that would get in the way of any new floor shifter and other related stuff connected to it. NOT joking. This is the "nerd 4x4".). Thanks again.