I have had 4wd issues since the beginning of winter. When I put the truck in 4wd on dry pavement the something in the front wheels seems to be binding. They wheels feel and sound like they are dragging. When I disengages 4wd something thumps really hard because of all the tension being released. When I engage the 4wd while in the snow it kinda works but isn't right. The truck wants to pull one way or the other and wont go straight down the road. Today i decided to jack the truck up and engage the 4wd and put it in drive to see if all wheels are spinning and if i could hear any noise. When the 4wd is engaged only one of the front wheels spins at a time. Shouldn't they both be spinning? I can stop one and the other will start spinning. I have the ADD hubs. Any help would be awesome. This has been driving me nuts.

 

One tire spinning at a time is normal for an open diff. I apologize in advance, but you have driven 4wds before, right? They don't have very good manners on pavement. No offense if something is really wrong.

 

As stated above one tire spinning while the other does not is normal for an open diff. (front third member)

4wd manners on road are strange if you are not used to them. Caveat here is that is is NOT your transfer case <---- need to put that out there before it gets out of hand.

Have you driven 4wd's on the road before? Not trying to poke fun but for a first time high traction experience 4wd is a little..... "odd".

 

I thought these had locking front diffs? I haven't driven 4wds very much but i have. My truck will barley move on dry pavement while in 4wd like the brakes are on. Its bad.

 

On dry pavement, your vehicle usually will drag a bit in 4wd, especially when not going straight. If you're having binding issues though, I would check the gearing of the front and back. It's possible someone swapped a diff, and they have slightly different ratios (eg: 4.30 and 4.56)

 

what do the cv joints look like? are the boots cracked open anywhere? this could be causing the issue with a collapsed joint. Check both ends. does it get worse when on full lock?

Just a couple of thoughts. it is a 91 and the CV boots dont hold up well on any vehicle

 

That's a thought. . . did you just buy this thing? Did the 4wd work properly before this winter? Does it look like either diff was recently removed?

If this WAS the case it would be asymptomatic with the front end in the air, as you described, but a real handful on low traction surfaces, and pretty worthless on pavement, also as you described.

 

Its possiable the axel is binding on worn spindle bushing.

 

You could disconnect the rear drive shaft and then try and drive it in 4WD.

 

The axles look good and they dont pop or grind in either 2wd or 4wd.

I bought the thing last spring but wasn't able to drive it until July. On Halloween the rear diff blew up and I replaced it. I didn't even think about it having a different diff ratio. I got a replacement diff from a 91 with the 3.0. Did they use different ratios for that year?

 

From the factory they are open front and rear. If your rig has "sluggish" issues on dry ground while driving straight then something else is wrong. If it binds a little on dry ground while turning then that is normal.

 

If you are saying you have a 4cyl, I believe the ratios are different.

On a side note: if that IS the problem I am duly impressed at annoyingrob's powers of deduction given the absence of key information (such as "I swapped my diff and now my 4wd doesn't work").

 

No problem with the truck at all. I did the same thing to my 4Runner (my first 4wd) I've learned that it just isn't meant for high traction use and just to be sure then just put it through this simple test: find a straight path and put it into 4wd and go straight for a bit and if it doesn't bind up then you don't have a problem. The only time it should bind on high traction surfaces is when you start turning it. I believe that has something to do with not having a center differential and that force some of the tires to spin at rates that the truck doesn't want it to spin hence the binding. While on a really slick surface this wouldn't be a problem.

 

Could be different if the 3.0 was either a different trans. that you have (A/T vs. M/T) or if it was equipped with the factory 31" tire option. So check the gear ratios front and rear:
- http://www.4crawler.com/4x4/4R_TechI...oDetermination

 

No i have a 6cyl 3.0 and i just figured that all of them from that year with the same engine had the same rear differentials. I never used the 4wd until it started snowing here. I never thought to check it after i changed the rear diff. I was just happy to be done with it.

 

There's a few different ratios used. Off the top of my head, I believe 4.10, 4.30, and 4.56 were all available on 2nd gens.

is your speedo off now that you've swapped your rear end? If so, that's a sure sign your new rear-end has a different ratio.

xfactor203: I'm good at that

 

Put all four corners up on jackstands. Put it in neutral. Rotate the front driveshaft and count the revolutions of the driveshaft vs the revolutions of the front tires. Just over four rotations on the front driveshaft to one rotation of the wheels, you have 4.10s, four and a half rotations and you have 4.56s, almost five rotations, and you have 4.88s.

Repeat the same for the rear. Take you about half an hour or so.

 

Thanks for the tips. I will try that next week when I get back. Today I was driving on pure ice and put it in 4wd and it seems like I have the wrong diff. At slow speeds the truck feels like it bouncing. I will also go back to the junk yard and see what tire package and transmission the donor truck has in it.

 

Rob, I could be wrong but isnt it two tires rotations for every "xxx" rotation of the driveshafts. if you only rotate the front tire once wont you get like 2. something as your amount of driveshaft rotations? forgive me if im wrong....

Also Skid mark, I am going through the exact same problem with a 95 pickup I just purchased and your symptoms are identical to mine.... and i have found that my front diff was swapped out and replaced with one that has a different gear ratio.

the following is a link to my thread and you might find some additional info there:
https://www.yotatech.com/forums/f116...ng-4x4-201695/

 

LOL this was my first question ever, on these forums. Here is what I learned, these trucks are not like the 4x4 explorers where you just push the button and go. I think people think all 4x4 are this way. But there not. When they told me that my truck would bind in 4x4 I was kinda floored. I had a 4x4 exploder and I could run 4x4 all day on any surface, but these trucks are diffrent. In 4x4 you can go straight in 4x4 on most surfaces as long as your tires and gearing are correct, if you have to turn for any reason and its not toatally slippery then disengage it for the turn and engage it when needed. I also hear that only 2 wheels spin at a time 1 front 1 back. You know how the back fish tails on snow when in 2x4, I think the front is the same way. If your getting noise I would check the spindle bushing. But all the strange you would think are something wrong are usually the way it is. Am I making any sense, lol. These are things I learned here. Then one day I put the visor down, and i'll be a monkey's uncle, right there on the visor was a card that described every bit of what everyone told me. In my mind I could have swore there was something wrong with the truck. But there wasn't!