Engaging 4x4 in k5....

Nissan11

Nissan11

Well-Known Member
Joined
Nov 29, 2005
Location
Marston, NC
I finally got the blazer running good and am ready to test it. Its an 85 k5 blazer and my question is how do I engage the 4x4H and 4x4L? Im not sure whether to lock the hubs first, and if I have to be in neutral to engage the transfer case. Also once its in 4x4H how do I engage 4x4 Low? Also how do I disengage 4x4? Thanks!!
 
You should have NP208 T-case, unless someone has swapped it.

You can "shift on the fly" from 2WD to 4-Hi, although I don't do it at high speed. Just shift it while rolling.

To go from 4Hi to 4-Lo, put the trans in Neutral, then in one motion pull the T-case lever from 4Hi, past N, to 4Lo. (I think you have to move the lever over towards the passenger side before doing this) Let your foot off the brake when doing this, so that the truck can move a little to help the gears line up in the T-case. If it won't go, roll forward very slowly with the trans in Neutral.

It doesn't matter much if your hubs are locked or not, but you should not shift from 2WD to 4Hi at any speed more than a roll if the hubs are not locked. This is because unless the hubs are locked, the front D-shaft is not spinning when in 2WD, and when you try to pull into 4Hi, the gears in the T-case will be at significantly different speeds if you are driving.

I hardly ever lock my hubs unless I'm on a hard trail. I shift into 4WD Lo without the hubs locked all the time at my house to make it easier to back up to a trailer, drive slow through a field, etc. At those times I don't need the 4WD, I just need the low range.

To get from 4Hi to 2WD, just shift the lever at whatever speed you're going. To get out of 4Lo, put the trans in Neutral and shift to 4Hi, and then 2Hi if you want. If the T-case "binds" and won't shift, make sure your wheels are straight, and slowly roll forward or backward a little while trying to shift it. Unlocking your hubs can also help.

Hope this helps!
Richard
 
Thanks for the help! Also the lights that show what gear the transmission is in dont work. Is this the correct order from left to right- Park, reverse, nuetral, overdive, drive, 2 and 1?
 
Well today I decided to test out the 4x4 on the blazer. I did a run through the woods behind my house in 4H and it worked fine. I then put the truck in
4L and proceeded to navigate a rock garden. It turns out the truck was not in 4x4. It was in low range however, but the front tires wont spend. I ajusted the t-case rod on the passenger side of the t-case because it looked like it was not letting the 4L engage becuse the arm on the end of the rod was straight with the rod and could not move foward anymore. I loostened both bolts about 3 turns and put the truck in 4L again. This time the t-case shifter was able to move further and I assumed it was now in 4L. I started into a deep mud hole and when I had the front end down in it I put it in reverse and neither front tire would spin. The 4L was still not working. I then put the tranny in neutral and put the t-case in 4H but the front tires still would not turn. No matter what gear the t-case was in it was in 2x4. I got pulled out eventuall but I dont know why 4H worked earlier and wont work now, and why 4L wont work at all. Did I ajust the t-case shift rod the wrong way? Thanks for any help.
 
Also, the t-case and transmission were out last week. The truck is a 85 k5 blazer and the tranny I put in was a 92 if that makes a difference. And when I went to bolt the t-case shift linkage to the side of the t-case it would not fit tight so I loostened the 2 ajuster bolts several full turns to get it to finally slide on.
 
You have the arm on correctly, as in it is engaging the keyed portion of the rod sticking out of the t-case? The best way to adjust them is to unhook the adjustable portion, manually put the t-case in 4L, then adjust the arm to that spot. If it's adjusted properly for 4L, all other gears should hit fine, as 4L is the furtherest distance the linkages must travel.
 
When I ajust it to 4L should it be tight in 4L as in there is no play in the rod or arm in 4L for it to move any further foward?
 
Ok I have ajusted it several ways and come to the conclusion the problem is in the front end. The truck has Mile Marker manual hubs. There is a pile of gravel at my house and when I tried to climb it in 4H the 4x4 worked for a few seconds, then I felt some jerking and it slipped back into 2x4. I backed off the pile and did the same thing in 4L. The 4x4 was working until I got to the top and I felt the same jerking and the truck went back into 2x4. I turned the hubs as far as they would go in the direction that says "lock". Whats the deal? Are my hubs stripped? Thanks.
 
Yes, it shouldn't quite be tight, as you want to allow for some movement in the drivetrain and body. As long as it is engaged solidly, the arm should be able to move some. I doubt the hubs are stripped. They usually work or they don't, but that would be something to check first since it's the easiest. What you're describing sounds like a possible a broken transfer case mount, or a blown up planetary in the t-case. Just always start with the easiest things, then work up, which is what you seem to be doing.
 
If the tranfer case was the problem then wouldnt that make front driveshaft not spin? I got my brother to look under the truck as I was on a gravel hill and he said the front driveshaft spins. If its not the hubs, what is most likely the problem?
I just pulled the cap off one of the hub and everything inside the hub is covered in mud. I took out the pin but I cant get any of the other parts to come out to clean them. Is it OK to spray out the hubs with a water hose and how do I get the rest of the parts out?
 
Well, the driveshaft could still spin, but you sound like you've found the problem. To remove the hub, you'll need to pull the snap ring(s) off the stub shaft, then with a pick or clotheshanger or whatever tool you can make work, remove the large snap ring from the inside surface of the wheel hub. This may take some time and probably a lot of frustration, but it will come out. DO NOT SPRAY IT WITH WATER! This will contaminate everything inside the hub, and then you'll be rebuilding everything, although it might not be a bad idea to repack the wheel bearings if there's that much mud inside the hub.

After cleaning the hubs with brake or carb cleaner, or even diesel fuel for that matter, LIGHTLY grease them. If you pack too much grease in there, they won't work still. Button everything up and try 4WD again.

If this doesn't cure your problem, I fear that it may be something else. I don't know the history on the truck, but I can help you along the easiest route to fixing it.
 
With a jack under the front axle, I put the hub cap back on and spun the tire. The tire will spin a good bit before the axle will turn with it. Is there supposed to be this much play in the axle and hub? Thanks!
 
Well, if there's that much mud in there, it can take a little bit before the lockout actually engages the axleshaft. Just clean everything well, then report back. But to answer your question, no, there shouldn't be that much play. If everything is working properly, the axleshaft should turn at the same time as the tire.
 
Do I need to remove the wheel and jack up the corner of the truck Im working on to remove the hub? Im not going to get a chance to work on it until tomorrow afternoon when I go home for the weekend.
 
As long as you aren't pulling the wheel bearings out, you should be fine with it sitting on the ground.

If you need any further help, send me a PM and I'll give you my contact info.
 
Ok I pulled and cleaned both hubs but 4x4 still will not work. If the hubs are good and the axleshaft is spinning, what should the problem be? What is in between the axle shaft and hub?
 
Well if the axleshaft is spinning, then the hubs are working. It could possibly be spider gears or ring and pinion related, but you'll have to pull the cover to find out about that.

You've covered all the basics, now you're gonna get dirty.
 
Are you 100% sure your hubs are still working correctly? Both hubs have to be locked otherwise neither front tire will pull unless you have a locker.

If you get under the truck with the t-case in 2wd and hubs locked can you turn the front driveshaft at all? You should not be able to spin your front driveshaft by hand with the t-case in 2wd and your hubs locked. With hubs un-locked the drivehshaft will spin. You can then try and put your t-case in 4wd with the hubs un-locked, you also should not be able to spin the front driveshaft. If the driveshaft spins in one of these two situations you can help find out where you need to look at your front axle or your transfer case.

Although if something is broken it still may not allow you turn turn the driveshaft by hand if something is still grabbing it but when torque it applied the broken part is letting it slip.
 
What size tires are you running? I put warn basics in my 85 K10 and they have metal caps and everything and I run 33x12.5's and have had no trouble from them and they cost less.
 
Im running 35" mud terrains right now. I replaced the stripped hub with a stock one and it works great but now the other mile marker hub is broken. The spring on the cab got jammed at the bottom of the cap and wont turn and I broke it trying to get it out. Now I need a new cap, mabye even another hub.
 
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