4WD Question Re: Tire Rubbing (Only Happens In 4WD)

[SixPoints_Kev]

Hoping someone can answer this question as I have zero knowledge regarding the 4WD system in the Rams.

I have a 2017 2500 4x4, no lift or level. I have 295/65/20 tires (about 35.5" tall and 11.5" wide). I choose an 11.5" tire to avoid the rubbing issues I might have with the 12.5". With the truck in 2WD, at full lock, I have no rubbing at all. When I put the truck in 4WD Lock and drive around, I notice there is a significant amount of rubbing (or what seems to be rubbing) when making turns from 3/4 to full wheel lock. If I hit a large enough speed bump, pot hole, or even a driveway fast enough, I notice some rubbing as well (again, what seems to be rubbing to me). Can someone explain whats causing this? If it isn't the tires rubbing on something, what could it be? What is going on mechanically when I change from 2WD to 4WD?

Thanks,
Kevin

 

[shadowhawk]

are you just hearing the normal "grind" of 4wd at low speed? Have you looked at your tires for signs of rubbing on the UCAs?

 

[ramportin1]

Sounds like normal 4X4 truck. Your front wheels have traction basically and its kinda your truck saying i dont need to be in 4 wheel drive. It usually feels like your back tires are having to kinda force your front tires to move and they are grabbing something, because they are lol the ground. I mean maybe you got something going on but from what youve said thats normal when you got traction and big tires in 4X4 and 35's are definitely considered big tires in this case

EDIT: In basic terms, in 4X4 your front is pulling from a slightly diff angle in a sharp turn then your back is pushing, the bigger and more tread tires will make this more dramatic feeling when the front has traction because those front wheels are pulling from one angle and your back is trying to push them in a slightly diff angle which is not good to do. When 4X4 is needed IE no good traction, the front will slide a bit during those sharp turns and you wont feel anything (or not much) but when the front has full traction you will feel it being pushed and should take it out of 4WD

 

[Ken226]

Possibly your noticing the binding that occurs when your front wheels track around a larger radius than your rear wheels.

If that's the case, it implies that this is your first 4wd and you don't realize that this is pretty hard on your transfer case. I recommend you not use 4wd when your in a situation which would cause this, such as turning on dry pavement with 4wd engaged.

I'm I'm mistsken, and your talking about something else, disregard.

 

[ramportin1]

This ^^

 

[SixPoints_Kev]

I've checked to make sure nothing is rubbing on the UCA's and the inside wall of the tires look good. I do have Trail Grapplers, so maybe it is the tire just grabbing and pulling at the pavement. I don't make it a point to constantly drive around in 4wd, I just turn it on once in a while (when not actually needed for snow or traction) to get it some use, and I only drive around for a few miles. It happened to be raining quite a bit here yesterday so I turned it on for the short drive home. But I did notice that "grabbing/rubbing" feel from the front tires and thought I'd ask. Thanks all around guys!

 

[Demon-HeMi]

yeah pretty much dont use your 4wd on the road, its not needed

 

[ColdCase]

In other words, when you go around a turn, your front wheels turn more than the rear as they travel a little more distance. As a result the front and rear axles turn at a slightly different rate. The sharper the turn the more the difference. However, when in 4 lock the front and rear axles are locked together by the transfer case and they are forced to turn at the same rate... somethings gotta give. The drive train will wind up like a spring a little but eventually either your tires scrub, which is what you are noticing, or your transfer case blows apart from all the stress. Driving in 4 lock on surfaces with good traction is very hard on drivetrain components.