Ford Ranger bucking under acceleration in 4X4

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Hi folks,

I tried accelerating in 2WD and its smooth and fine. In 4X4 it bucks like it's missing and feels pretty rough. The 4X4 engages smoothly.

Any thoughts to what this is? Why does this truck hate me so much? It's only got 85k on it roughly. It's had its fair share of kinks.
 
Maybe someone beat it like a red haired stepson?

You aren't using 4x4 on a paved road right?
If so you are experiencing binding and abusing your vehicle.
 
Are all the tires the same size front and rear? Worn evenly? I would not engage 4WD on pavement unless there is sand, mud , or snow present.
 
Sorry, this was a gravel road. Really soft for the most part....maybe it wasn't soft enough? If that was the case, It might have been binding, but it seemed pretty loose to me.

The tires are all the same and inflated to within 2 lbs of each other.

This is the first I've seen it happen so maybe it was too firm. I'm not used to Fords 4X4.

I will admit it did flip it on momentarily on pavement to see if it repeated itself.
 
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Originally Posted By: ryan2022
Sorry, this was a gravel road. Really soft for the most part....maybe it wasn't soft enough? If that was the case, It might have been binding, but it seemed pretty loose to me.

The tires are all the same and inflated to within 2 lbs of each other.

This is the first I've seen it happen so maybe it was too firm. I'm not used to Fords 4X4.

I will admit it did flip it on momentarily on pavement to see if it repeated itself.


Knock that off for one thing. That's like saying I tried neutral drop launch because my transmission exploded when I held the brake pedal...
 
It could be binding up. 4WD needs slippery surfaces, sand, etc. to work properly. I'd try it on sand if it's possible and see what happens.
 
Thanks guys, maybe even on the gravel road I hit a dirt patch. I'll check the transfer case fluid level tomorrow, but I really hope that's the case. It engages perfectly. No noise and its smooth.
 
Originally Posted By: horse123
Originally Posted By: ryan2022
Sorry, this was a gravel road. Really soft for the most part....maybe it wasn't soft enough? If that was the case, It might have been binding, but it seemed pretty loose to me.

The tires are all the same and inflated to within 2 lbs of each other.

This is the first I've seen it happen so maybe it was too firm. I'm not used to Fords 4X4.

I will admit it did flip it on momentarily on pavement to see if it repeated itself.


Knock that off for one thing. That's like saying I tried neutral drop launch because my transmission exploded when I held the brake pedal...


lol. yeah. You got me there. Momentary dumb move.
 
What setting? Just 4X4 HIGH? 4X4 HIGH should be fine on a gravel road at reasonable speeds in that truck. 4X4 LOW is not for a gravel road, or really anything called a road.

Your truck has an open front differential that's engaged to the front wheels all the time. Its transfer case is meant to be shifted into 4X4 HIGH while the truck is moving (at lower speeds), and it should be fine on a gravel road.

If this is happening in 4X4 HIGH, I think the truck has a problem, probably in the transfer case. If you are trying to use 4X4 LOW on a gravel road, the truck will buck and feel pretty rough. That's for mud and crawling over stuff, not going down the road.
 
Originally Posted By: 01rangerxl
What setting? Just 4X4 HIGH? 4X4 HIGH should be fine on a gravel road at reasonable speeds in that truck. 4X4 LOW is not for a gravel road, or really anything called a road.

Your truck has an open front differential that's engaged to the front wheels all the time. Its transfer case is meant to be shifted into 4X4 HIGH while the truck is moving (at lower speeds), and it should be fine on a gravel road.

If this is happening in 4X4 HIGH, I think the truck has a problem, probably in the transfer case. If you are trying to use 4X4 LOW on a gravel road, the truck will buck and feel pretty rough. That's for mud and crawling over stuff, not going down the road.


That's what I was thinking. it was soft enough that it should have been fine. I'm going to check the level in the transfer case.
 
I have a zillion miles off road in a Ranger 4x4. Did trail condition surveys for the Park System for decades. Inflating tires to the same pressure is not the key in 4x4's. Rolling diameter is the key.

If the truck has an empty bed, the rear tires are effectively taller than the fronts because of no load. I had a camper shell and a bed full of survey tools and get unstuck stuff like extra jacks and a come-along in the back, so mine was much better balanced. Even then I had to run different tire pressures front to back.

Set your front tires for best wear pattern. Maybe 32 psi... Take a tape measure and measure from a hard flat surface like a parking lot, from the ground to the top rim lip on the fronts. Now adjust your rears to that same height. Does not matter what the pressure is. Unladen it'll be like 24 psi or something. But all four wheels will now be rolling the same height. Bucking will be gone.

Put a load in the bed and you'll need to air up to keep the rolling height the same... 4x4 needs attention from the operator. This is not AWD with a viscous center coupling. This is a locked mechanical system. It will fight any difference in rolling diameter except on dry fluffy beach sand or snow ...
 
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Maybe you have a crummy u-joint in the front drivetrain. It doesn't show up unloaded but somehow a load changes things.
 
Thanks BrocLuno, You've given me hope! That could very well be it. I've never pushed a Ranger in 4x4 before. I'll give it a shot next time I'm out.

Originally Posted By: BrocLuno
I have a zillion miles off road in a Ranger 4x4. Did trail condition surveys for the Park System for decades. Inflating tires to the same pressure is not the key in 4x4's. Rolling diameter is the key.

If the truck has an empty bed, the rear tires are effectively taller than the fronts because of no load. I had a camper shell and a bed full of survey tools and get unstuck stuff like extra jacks and a come-along in the back, so mine was much better balanced. Even then I had to run different tire pressures front to back.

Set your front tires for best wear pattern. Maybe 32 psi... Take a tape measure and measure from a hard flat surface like a parking lot, from the ground to the top rim lip on the fronts. Now adjust your rears to that same height. Does not matter what the pressure is. Unladen it'll be like 24 psi or something. But all four wheels will now be rolling the same height. Bucking will be gone.

Put a load in the bed and you'll need to air up to keep the rolling height the same... 4x4 needs attention from the operator. This is not AWD with a viscous center coupling. This is a locked mechanical system. It will fight any difference in rolling diameter except on dry fluffy beach sand or snow ...
 
Dont think that running your tires at 24 psi is going to fix a mechanical problem. Besides i doubt that truck is meant to run with the tires that low. I agree with whoever said to check the transfer case
 
How sharp were the curves?

If it does it in a straight line.. there is definitely a mechanical issue.

Are all 4 tires same size and wore even?

Even on Dirt and Grass Turning sharply will cause major binding.

There is no center differential. So front and back are fully coupled to each other. When you turn in a circle the tires travel different distances. They have to physically slip on the ground.

Its ok to 4x4 on pavement only in a very straight line. Such as a Drag Strip or when very slippery conditions ie mud or snow.

I would check condition of the gear oil in both axles, as well as transfer case.

Transfer case takes ATF, I would recommend a HQ similar to redline D4


Nothing you said so far makes me think think is anything other than binding and basically operator error.
 
In a straight line this should be fine. It's when you make turns that you get binding. The tighter the turn the faster it binds. I could see a long gentle curve taking a while to hit that point. I have to wonder if you have different sized tires on the truck--are they worn evenly? Not just the same size but the same tread depth.

I'm not sure what the transfer case has to do with this--isn't this a classic transfer case, no differential, either the front driveshaft is lock-step with the rear?

This may just be the way it is. My truck binds horribly in winter when I need to use it in 4WD. I'll back into my driveway, and every 10 feet it will slow&stop, then "pop" it's free again. Lock to lock turning does that. But in a straight line it's fine.
 
Thanks supton,

I hope that's it. It was actually in a straight line that its binding. Even at slow speeds.

I'm going to check inflation, levels, etc... this morning.
 
Originally Posted By: supton
In a straight line this should be fine. It's when you make turns that you get binding. The tighter the turn the faster it binds. I could see a long gentle curve taking a while to hit that point. I have to wonder if you have different sized tires on the truck--are they worn evenly? Not just the same size but the same tread depth.

I'm not sure what the transfer case has to do with this--isn't this a classic transfer case, no differential, either the front driveshaft is lock-step with the rear?

This may just be the way it is. My truck binds horribly in winter when I need to use it in 4WD. I'll back into my driveway, and every 10 feet it will slow&stop, then "pop" it's free again. Lock to lock turning does that. But in a straight line it's fine.


Well I mean that's what I'd expect from a toyota but that doesn't mean it's normal...
 
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