4 wheel drive not engaging properly?

[TimBrunett]

I put my new Ram in 4 wheel drive Lock and tried it on a grassy field. I jerks and jumps especially as you turn right or left. It feels like it not engaging completely and possibly slipping in and out of engagement. 4 wheel LOW was about the same. I was sitting still and in neutral, turned the knob and got the message on the EVIC that it was ready.

This is my first 4x4 Ram so is it me obviously not doing something right or what? Dealer said bring it in and I will.

Can anybody comment on what I might have here?

Thanks

TB

 

[DonFitzwater]

Jerking and jumping while turning in 4wd means that your 4wd is working! The wheel joints at the knuckles are binding up and this is normal.

 

[jhenderson]

When you turn the front wheels they travel different distances from each other as well as the rear. This causes a bind in the driveline. The more traction you have, the more pronounced the jerking and binding. All perfectly normal.

 

[Joseph Donnelly]

When you turn the switch, you are "requesting" 4WD. EVIC will tell you if it is still in the process of engaging. Generally, lightly applying or releasing the accelerator pedal will help. Avoid tight turns in 4WD as the above noted problem is hard on the universal joints, etc.

 

[TimBrunett]

I was in a small field and did turn it about ¾ of the way which was probably too tight of a turn. I’ll have to remember about tight turns in 4WD. I just wasn’t expecting the jumping-jerking and I thought that the differential would compensate for the wheel speed difference. It’s been a long time since my last real 4X4.

Joseph – I saw the EVIC message and waited a few seconds and it when it said it was engaged tried it. It was in neutral when I went from 2WD to 4W Lock, but next time I’ll try it in Drive and applying/releasing the accelerator. I don’t need 4WD much but I do need to know how. Gonna re-read the manual.

I appreciate everyone’s comments because it sounds like the only problem is my lack of experience with 4X4’s.

TB

 

[TimBrunett]

OK guys

I tried it again in the same field. It's a lot better when you don't turn real tight and you know what to expect.

Thanks

TB

 

[Powder Extreme]

The differentials in the axles can and do compensate for speed differences between the tires on the SAME axle, however the jumping and jerking you are experiencing is caused by the front tires being forced to turn at the same speed as the rear tires. Except you are in a tight turn meaning the front tires need to turn faster than the rear tires, but since there is no differential between the axles, everything "loads up" and the strain finally releases causing the jumping and jerking. Every four wheel drive vehicle will do it to some degree. A full time 4 wheel drive or All Wheel Drive has a form of center differential or a clutch in the transfer case that will either compensate for the speed difference or allow it to slip, which is why they don't jump and jerk at all.

 

[gtoli]

Plus , if your 3500 is like mine, the rear axle is limited slip and will chatter and bind a little, especially in 4WD.

And what PE said.

 

[mpaulson]

If you are on slippery enough ground to actually need 4x4, you wouldn't notice it as much, or at all. On real mud or in the winter which is when I mainly use 4x4 the roads are basically the same as a skating rink and you don't feel anything at all when you turn because the wheels can slip enough to not send the feed back to the steering wheel.
What you are feeling is normal, but like others said, hard on the u-joints and if you are feeling this, then you likely don't need to be in 4x4 due to enough traction.
I hope someone comes out with a plug in gizmo that will make it so that the front axle doesn't engage when activated so that we can use 4x4 low but still be in 4x2 for low range maneuvering of heavy loads in tight places etc. Like BD made for the second gen trucks which I had on one.

 

[TimBrunett]

The differentials in the axles can and do compensate for speed differences between the tires on the SAME axle, however the jumping and jerking you are experiencing is caused by the front tires being forced to turn at the same speed as the rear tires. Except you are in a tight turn meaning the front tires need to turn faster than the rear tires, but since there is no differential between the axles, everything "loads up" and the strain finally releases causing the jumping and jerking. Every four wheel drive vehicle will do it to some degree. A full time 4 wheel drive or All Wheel Drive has a form of center differential or a clutch in the transfer case that will either compensate for the speed difference or allow it to slip, which is why they don't jump and jerk at all.

That describes what I was feeling exactly. I tried it later, still on the same dry ground, but not turning nearly as tight and everything was fine. It was me not knowing enough about it and trying it out on dry hard grass.
I just rolled up 290 miles yesterday so it’s still like brand new to me.
Thanks for the help.

Tim Brunett

 

[TimBrunett]

If you are on slippery enough ground to actually need 4x4, you wouldn't notice it as much, or at all. On real mud or in the winter which is when I mainly use 4x4 the roads are basically the same as a skating rink and you don't feel anything at all when you turn because the wheels can slip enough to not send the feed back to the steering wheel.
What you are feeling is normal, but like others said, hard on the u-joints and if you are feeling this, then you likely don't need to be in 4x4 due to enough traction.
I hope someone comes out with a plug in gizmo that will make it so that the front axle doesn't engage when activated so that we can use 4x4 low but still be in 4x2 for low range maneuvering of heavy loads in tight places etc. Like BD made for the second gen trucks which I had on one.

I wasn't mentally prepared for the normal part. I thought I had a great big problem with my new truck. I'm glad it was very short so probably no damage to the u-joints. And more than glad that TDR is here with guys like yall who have way more experience than me. My neighbor told me if I want to do that I should have got a Suburu. Ha ha to that.

Thanks for the help

Tim

 

[Joseph Donnelly]

You could keep a Subaru in the bed as a spare, lol.

 

[Terry Jay]

Just to note, try to engage the 4WD about once a month for a short period, say a couple miles on a relatively straight road. It just seems to like a little periodic exercise, but not to the point of excessive pain.

 

[TimBrunett]

Just to note, try to engage the 4WD about once a month for a short period, say a couple miles on a relatively straight road. It just seems to like a little periodic exercise, but not to the point of excessive pain.

I'll do that. It should keep the lube circulating instead of letting it settle out too much and it's not a pain.

Thanks

TimB