1994 Explorer 4x4 engaging while turning

[mxr577]

Hey all,

I have a strange issue that happens while I am turning and re-center the wheel. While driving and returning the wheels straight the vehicle would dart slightly in the direction I was returning the wheel to. So left turns, would cause the vehicle to dart right just as I return to the straight wheel, and vise versa. For a while I assumed it was just an old vehicle that had some slop in the steering box, and/or the tires maybe weren't the best or maybe low. It almost felt like when a tire is flat and it pulls you towards the flat side. Clearly I would check the tires and they were not flat. I also, adjusted the steering box adjusting screw recently and although the steering feels better it still darts.
I had the front end on jack stands today and turned the wheel back and forth lock to lock. At a quicker speed of turning the wheel I could see the tire chattering as it crossed from left to right and right to left, so when it was nearing straight. I made the turn lock to lock slower and noticed the wheel would actually spin a little when it crossed over, and noticed it was the front axle engaging the wheel. The front drive shaft was also spinning. The hubs are manual so I know they were not locked and I could spin the front drive shaft freely so I know its not in 4x4.

I cant imagine this is normal operation, and I cannot understand what would cause the wheel to engage if the hub is unlocked. Never mind the front drive shaft engaging. Has anyone experienced this or have any possible explanations of what could cause this?

 

[RangerX]

Welcome to the forum!
I read your testing description several times through to be sure I got the picture, you’re turning the steering lock to lock with both front wheels off the ground. I assume this as with engine running, trans in park or neutral, and tcase in 2wd.

I cant imagine this is normal operation, and I cannot understand what would cause the wheel to engage if the hub is unlocked. Never mind the front drive shaft engaging.

I would not rule out the hub(s). It’s possible for a manual hub to have issues, and the hub would make the most sense, to me. Having the hub connect even a little will connect it, the wheel, the axle shaft and the front driveshaft as one, causing them to turn.
Turning of those shafts has to come from either the wheel or the tcase.
You might try swapping the hubs side to side and see if that causes the other side to spin. Maybe that hub is gunked up and can’t fully disengage...

 

[Roadrunner777]

I had something similar to this 'wheel jerk', although slightly different conditions. The way it happened for me was I would engage my manual hubs for the first time in winter, and then engaged 4x4 while driving, it would jerk just like that. It was initially quite severe and then it smoothed out. It ended up being the outer axle U-joint on one side. Now, it's happening for you with the hub disengaged, so that might not be it, but idea that it happens when turning and ok when straight is classic U-joint.

I think I would rebuild the front wheel bearing assemblies. There's two great thread on doing this with procedures and photos. When you have it taken apart, you can get to the U-joints. The left side axle just comes out, the right side you have to take apart a slip-joint. This is probably long-overdue maintenance anyway and I think you will discover and address the cause along the way.

Ah-Ha! This is it: How-To: 1st Gen Ball Joints / U Joints / Spindle Bearings
and this: My 1st Gen front Brake job Diary

You won't have to do everything in those thread, but it's a great guide if you decide to go that direction. Then again, this is just a gut call... but like I said, it's good maintenance and not wasted time/effort.

 

[mxr577]

Welcome to the forum!
I read your testing description several times through to be sure I got the picture, you’re turning the steering lock to lock with both front wheels off the ground. I assume this as with engine running, trans in park or neutral, and tcase in 2wd.



I would not rule out the hub(s). It’s possible for a manual hub to have issues, and the hub would make the most sense, to me. Having the hub connect even a little will connect it, the wheel, the axle shaft and the front driveshaft as one, causing them to turn.
Turning of those shafts has to come from either the wheel or the tcase.
You might try swapping the hubs side to side and see if that causes the other side to spin. Maybe that hub is gunked up and can’t fully disengage...

To start you are correct in my testing. Its always tough to see how much you miss while describing until someone from the outside asks more, thank you for this. The vehicle was on jack stands holding the front two wheels off the ground, the vehicle is running, trans in park, and the t-case is in 2wd.

I do like your thoughts on the hub, makes sense that either the wheel or t-case is what is making the axle/drive-shaft spin. I will certainly try swapping the hubs. I might even have a spare hub I can throw on now that we mention it.
The one thing I would find strange about it being the hub is that it seems the wheel is being given power causing it to spin. Sometimes it is almost a quarter turn, then anywhere between that and nothing. Also, no one is spinning the wheel and I would find it difficult for a static wheel to turn the whole front drive-train. But the wheel is spinning, so even if the t-case is giving the power, the hub is still engaging when it shouldn't be.

 

[Turdle]

If the internal spring inside the hub was broken would it cause this issue?

 

[mxr577]

I had something similar to this 'wheel jerk', although slightly different conditions. The way it happened for me was I would engage my manual hubs for the first time in winter, and then engaged 4x4 while driving, it would jerk just like that. It was initially quite severe and then it smoothed out. It ended up being the outer axle U-joint on one side. Now, it's happening for you with the hub disengaged, so that might not be it, but idea that it happens when turning and ok when straight is classic U-joint.

I think I would rebuild the front wheel bearing assemblies. There's two great thread on doing this with procedures and photos. When you have it taken apart, you can get to the U-joints. The left side axle just comes out, the right side you have to take apart a slip-joint. This is probably long-overdue maintenance anyway and I think you will discover and address the cause along the way.

Ah-Ha! This is it: How-To: 1st Gen Ball Joints / U Joints / Spindle Bearings
and this: My 1st Gen front Brake job Diary

You won't have to do everything in those thread, but it's a great guide if you decide to go that direction. Then again, this is just a gut call... but like I said, it's good maintenance and not wasted time/effort.

Ok, this got me thinking a little. Of coarse I very recently just did the rotors and wheel bearings, like around 1000 miles ago. But easy enough to take back off to get to the u-joints. This vehicle has just hit 110K miles, and I have not had to do much to it since I got it around 40k miles. It has never been beaten on, and has been my daily driver for about 8 years. So, it probably has plenty of overdue maintenance.

Going along the path of a bad u-joint though. If this was too sloppy, or potentially a bad needle bearing on the spindle; could this be causing my spindle to "wobble" causing the spindle to jam into the splines on the hub thus engaging the hub and spinning the wheel?
Again, similar to my response to @RangerX I feel that the wheel was being given power not the other way around.

Thanks for the response and the links, very cool.

 

[Roadrunner777]

Ok, this got me thinking a little. Of coarse I very recently just did the rotors and wheel bearings, like around 1000 miles ago. But easy enough to take back off to get to the u-joints. This vehicle has just hit 110K miles, and I have not had to do much to it since I got it around 40k miles. It has never been beaten on, and has been my daily driver for about 8 years. So, it probably has plenty of overdue maintenance.

Going along the path of a bad u-joint though. If this was too sloppy, or potentially a bad needle bearing on the spindle; could this be causing my spindle to "wobble" causing the spindle to jam into the splines on the hub thus engaging the hub and spinning the wheel?
Again, similar to my response to @RangerX I feel that the wheel was being given power not the other way around.

Thanks for the response and the links, very cool.

My thinking is... if the U-joint is rusted tight, yeah, it could cause lateral force in the spindle and then I noticed just now you are in Maine? Road salt/sand much? Yeah, I'd get into the spindle at least to get to a known condition. It's a good therapeutic task, methodical cleaning and inspecting stuff.

 

[massacre]

My 4wd u joints were so badly rusted together that I could hardly steer the truck.
had to use a sledge to move the knuckle to remove the u joints. Just terrible.
So they can definitely bind up and cause problems

 

[mxr577]

My thinking is... if the U-joint is rusted tight, yeah, it could cause lateral force in the spindle and then I noticed just now you are in Maine? Road salt/sand much? Yeah, I'd get into the spindle at least to get to a known condition. It's a good therapeutic task, methodical cleaning and inspecting stuff.

Ok, thanks. I'll obviously be taking things apart again so this will be a point to check for sure. And its even worse than Maine; Massachusetts. At least Maine uses more sand than salt, Mass is just salt everywhere.

 

[mxr577]

Thank you to all that have replied so far and any future replies. The way it usually goes, I wont be able to dig into this this weekend but will be soon. As progress is made I will keep the thread updated with any finds/resolutions.

 

[massacre]

I am also in MA

 

[smegun]

Hey all,

I have a strange issue that happens while I am turning and re-center the wheel. While driving and returning the wheels straight the vehicle would dart slightly in the direction I was returning the wheel to. So left turns, would cause the vehicle to dart right just as I return to the straight wheel, and vise versa. For a while I assumed it was just an old vehicle that had some slop in the steering box, and/or the tires maybe weren't the best or maybe low. It almost felt like when a tire is flat and it pulls you towards the flat side. Clearly I would check the tires and they were not flat. I also, adjusted the steering box adjusting screw recently and although the steering feels better it still darts.
I had the front end on jack stands today and turned the wheel back and forth lock to lock. At a quicker speed of turning the wheel I could see the tire chattering as it crossed from left to right and right to left, so when it was nearing straight. I made the turn lock to lock slower and noticed the wheel would actually spin a little when it crossed over, and noticed it was the front axle engaging the wheel. The front drive shaft was also spinning. The hubs are manual so I know they were not locked and I could spin the front drive shaft freely so I know its not in 4x4.

I cant imagine this is normal operation, and I cannot understand what would cause the wheel to engage if the hub is unlocked. Never mind the front drive shaft engaging. Has anyone experienced this or have any possible explanations of what could cause this?

well long story short after snapping auto hubs and darting and dashing (rubbing hubs wrong way ) I bought lockers and a drive shaft or two after finding find frozen universal joints on the shafts little bit of work replacing the ujoints on the front axels but dooable take your shafts out buy some new seals or carfully reuse and take em into a shop like both would move in one direction but were frozen solid in the other direction causing thuds rubs and lurching