4WD jerking motion while turning

[Sequoia]

I am new to pickup trucks and 4wd, so please be kind. I have noticed that when I am in 4WD and I make a slow turn, the vehicle seems to jerk while engaging the turn. Any ideas? Is this normal? Should I be doing something differently? I am driving a 2018 RAM 2500 5.7L.

[WA Larry]

It's pretty normal. When turning things start to fight each other and bind up. You should have a narrow window where it's not too bad. It will get worse the further you turn the wheel. Either do Austin Powers multiple point turns or disengage 4x4 when doing sharp turns like turning around. Good luck with the truck, and happy camping.

[Dropthejacks]

That's normal when in 4WD. The front tires are pulling instead of being pushed like they are when in 2WD. You won't notice it as much in mud, snow, etc when the tires can slide a little, but you will definitively notice it on pavement. Nothing to work about.

[TonyMac]

I always come out of 4wd when I feel the jerking, I feel like it's telling me it's not supposed to do that.

[SilverBob]

Yes, this is normal. When you engage 4WD, your front and rear axles are forced to turn at the same speed. Since the front wheels have to travel farther in a turn than the rear wheels, something has to "give". On hard surfaces, this usually results in the jerking motion you described. On dirt, sand, grass or other low traction surfaces, one or more tire(s) will just slide a little and you usually don't even notice it. If you're experiencing that jerking, you very probably don't need to be in 4WD.

I'm pretty sure your Owner's Manual tells you not to engage 4WD unless the vehicle is on a marginal traction surface. Doing so is hard on the drive train.

[twinboat]

The gear ratios are a point or so different between the front and rear diffs. The jerking is going to happen on solid surfaces.

Your owners manual recommends not doing what your doing.

Take it out of 4X4.

[54Fun]

As others stated - the jerking is normal. The thing I had to come to terms with when I bought my truck (17 F350 Powerstroke) is that you really should only be engaging 4WD when you are on a surface that has some slip to it (according to the owners manual)... not dry pavement...it’s different that AWD on say an SUV that a computer that controls when and where it applies power to the wheels. Otherwise you can “do damage”. So driving in snow this winter, when I hit parts of the road that are clear and dry, I’m asking myself “so am I doing damage now since I’m in 4H??”....

[tuffr2]

I went from a smooth solid driving feel of an AWD vehicle to a 4WD truck. My friend told me you can drive in 4WD going straight and making slight turns. Also said I should not drive in 4WD on dry roads. That really, I should drive in 2WD always. If I get stuck then use 4WD to get unstuck.

The rear differential and front differential do not play well together.

4WD is not AWD in this case so yes, this is normal.

[ScoobyDoo]

Originally Posted by twinboat

The gear ratios are a point or so different between the front and rear diffs. The jerking is going to happen on solid surfaces.
.

I did not know that. But if they where the same you would still have issues. On a curve all 4 wheels travel different distances, so must turn at different speeds.

[winniman]

If you are unfamiliar with four wheel drive, I would suggest you completely read the owners manual. It will tell you when you can or should engage four wheel, and when you shouldnt. I can engage, and unengage mine up to 50 mph. I have owned four new Ford 4x4s, as well as my current Toyota Tundra. Every vehicle is different, and will let you know what it doesnt like doing. I find if I switch from 2 wheel to 4 wheel under very slight ecceleration, and vice versa, it avoids the mild clunking noise that you may get just switching it without throttle. All my Fords and my Toyota seem to prefer this method. Driving on bare pavement in 4x4 is not recommended. If you were launching a boat or towing a trailer up a steep paved hill, it would be acceptable for short periods, but as stated, take it out of 4x for making sharp turns on bare surfaces.

[Airmech]

Do NOT use 4x4 on dry pavement! Continued use will damage 4x4 components. It's ment for slippery surfaces. If is grabbing like you say, you don't need it and it's fighting itself. That's only going to lead to damage if continued to driven that way. I only use it when 4x2 can't get the job done.

[JohnRR]

There’s not much more that could be added now.

[Wildman4x4]

Originally Posted by tuffr2

I went from a smooth solid driving feel of an AWD vehicle to a 4WD truck. My friend told me you can drive in 4WD going straight and making slight turns. Also said I should not drive in 4WD on dry roads. That really, I should drive in 2WD always. If I get stuck then use 4WD to get unstuck.

The rear differential and front differential do not play well together.

4WD is not AWD in this case so yes, this is normal.

Your friend is mostly correct but not totally. You can turn as sharp as you want in 4wd but as the OP pointed out depending on the amount of traction you may get some jerking in the front axle.

Yes you should never ever ever drive in 4wd on dry pavement. When you put your vehicle into 4wd you are essentially locking the front and rear axles together. In a AWD vehicle the transfer case has a limited slip that allows slippage between the front and rear axles. But in 4wd they are locked together and if the axles don't get slippage then the transfer case CAN & WILL EXPLODE.

The statement that you should wait until you get stuck BEFORE engaging 4wd is not correct. You should engage 4wd as you feel the vehicle starting to slip or slow down due to loss of traction. Part of this depends on the type of 4wd system you have. If your vehicle has auto locking or no hubs on the front axle then you can do this on the fly. I have reached down and pulled the transfer case lever in my Jeep going 70MPH with no damage. Just let off the go pedal and push in the clutch if it is a manual tranny. In an auto tranny just let off the go pedal. If you have locking hubs then you first need to make sure you have them engaged BEFORE you get into a situation where you might need 4wd. If they are engaged then you can still put your rig into 4wd HIGH range on the fly.
Now if you need to go into low range your need to be going slower than 2MPH in most cases.

Originally Posted by Airmech

Do NOT use 4x4 on dry pavement! Continued use will damage 4x4 components. It's ment for slippery surfaces. If is grabbing like you say, you don't need it and it's fighting itself. That's only going to lead to damage if continued to driven that way. I only use it when 4x2 can't get the job done.

All good points.

[Jshopes81]

Originally Posted by ScoobyDoo

I did not know that. But if they where the same you would still have issues. On a curve all 4 wheels travel different distances, so must turn at different speeds.

Thats not all vehicles. Ford was doing it in the 70s and 80s, maybe later. They do that to spin the fronts a little faster amd it keeps the front pulling the rear. Im sure it depends on option packages and such.