2018 RAM 3500 with factory rear air suspension VOILENT REAR AXLE HOP

[BIG HIPS 3500]

I've looked and don't seem to find anything that I think applies to me so here it goes.... Driving down the road between 55-65 unloaded and hit a certain type of bump and sets off a VIOLENT CHAIN REACTION of REAR AXLE HOP that causes me to a total loss of control. I literally gota hold on till it stops! It's happened 3 times now and gets worse every time it happens. This is A SERIOUS SAFETY ISSUE, and I'm getting that sickening feeling that i'm going to get the run around from the dealer. I'd swear the air bag system is a huge part of the problem it's as if the problem is magnified by the air bags and the shocks are unable to hand the rebound (pure speculation on my part). The vibration went all the way to the front this last time, I couldn't even turn the steering wheel. I find it hard to believe I'm the only one dealing with this issue, unless my truck is a total lemon!! We are talking about a 2018 with 12,000 on it.. Does anybody have any suggestions??? or a corporate tech hook up that might seriously listen to what my complaints are?

 

[TFucili]

If it was a design issue with as many of them that are on the road it would have surely been reported here before. So I can only speculate that something is loose or broken on your truck. Get it to a dealer, so not only can they at least look at it, but you will then at least be on record as having reported it. The air bags are not a locating member, so I think it unlikely that they would be the root of it.

I am sorry you are having trouble, but, to be honest, it doesn't make sense to me that you experienced what you say, but apparently continue to drive the truck through multiple episodes.

 

[Wiredawg]

Recommendation: Take it to the dealer and give them a chance to fix it. Interesting the shocks didn't dampen the hop. There may be others who can share the experience, but I would turn it in ASAP.

Cheers,

Ron

 

[AEdelheit]

Im guessing you are unloaded with max tire pressure?? The shocks not having enough rebound is part of it but stiff suspension with poor shocks and over-inflated tires for the weight is a perfect combination to make that scenario happen if its a series of bumps very close together.

Good shocks with heavy rebound will help, if its still not enough control try lowering the tire pressure and see how it feels.

 

[AEdelheit]

I am sorry you are having trouble, but, to be honest, it doesn't make sense to me that you experienced what you say, but apparently continue to drive the truck through multiple episodes.

If its a series of bumps very close together it can cause issues most people will never experience and most bumps will have enough spacing for the suspension to recover before the next bump. Air bags ramp up pressure and rebound extremely fast so they can certainly contribute to the issue. If it was a component that located the axle , so leaf spring, it would be a constant issue not only under certain conditions.

 

[TFucili]

If its a series of bumps very close together it can cause issues most people will never experience and most bumps will have enough spacing for the suspension to recover before the next bump. Air bags ramp up pressure and rebound extremely fast so they can certainly contribute to the issue. If it was a component that located the axle , so leaf spring, it would be a constant issue not only under certain conditions.

For sure a series of bumps, or heavy washboard surface will be an issue with the amount of unsprung weight back there, especially empty. But You'd probably not be going 55-65 if that were the case. The airbags are supposed to have a delay built in so as not to contribute to such a circumstance.

I knew a guy that had a sort of similar situation with a pickup, not a dually, and it initially would only happen over large, sharp-edged bumps, but eventually became much more prevalent, and it was loose U-Bolts in that case.

 

[BIG HIPS 3500]

It's never been on a series of bumps (like breaking bumps caused by tractor trailers) it's always been on just one sharp bump... The first time it happened, dealer said nothing found. The second time and third time were relatively close like only few days apart, It's been at the dealer while I've been on vacation as I explained in detail to the top service guy. He's yet to get back to me....I'm curious what tomorrow brings

 

[TFucili]

Can you duplicate it, meaning is there a place fairly near the dealer that you can get it to do it "on command"? If so, get someone from the dealer to experience it with you.

I'd recommend calling FCA right now and creating a case. This does put heat on the dealer to not blow you off. Tell them you fear for your life to drive the truck. If you don't have any luck with the dealer, and can duplicate it, as above, tell them you want to meet the regional/district service guy and take him for a ride.

 

[BIG HIPS 3500]

Can you duplicate it, meaning is there a place fairly near the dealer that you can get it to do it "on command"? If so, get someone from the dealer to experience it with you.

I'd recommend calling FCA right now and creating a case. This does put heat on the dealer to not blow you off. Tell them you fear for your life to drive the truck. If you don't have any luck with the dealer, and can duplicate it, as above, tell them you want to meet the regional/district service guy and take him for a ride.

Worst fears just realized!! So they can't reproduce, and did a visual inspection only! they said a case was started and went up the food chain but nobody from corp. knows of any complaints like this. This is killing me, I been driving dodge trucks since i was 19!!! I finally buy my dream truck and this crap happens... I'm gonna call like you suggest tomorrow.

 

[TFucili]

Like I said, try to find a place where you can demonstrate it to them. I had to do that with the last Chevy I had. After I made it do it with the service manager in the cab they ran out of BS, then GM went into full stonewall mode, and I had to go Lemon-Law.

Good luck!

 

[EZeis]

2018 3500 SRW crew long 4wd here. Have the factory auto leveling suspension option. No issues. Rides beautifully empty or loaded. 50 or 80 psi in the tires. I've had it on all kinds of roads with no issue. Best option on the truck besides the Cummins and Aisin.
Definitely an issue to your truck. What, I have no idea. Is the system under or over inflating the bags? Defective shock(s)? Tires beyond 80 psi? Standard leaf springs installed instead of the leafs that go with the auto leveling suspension?
Like posted, try to find a road that will cause it and have a tech or two ride along.


Earl

 

[EZeis]

Your post doesn't say if your truck is SRW or DRW. If DRW, don't run 80 psi (sidewall) in the tires. Run the door psi.

Earl

 

[DonFitzwater]

Your post doesn't say if your truck is SRW or DRW. If DRW, don't run 80 psi (sidewall) in the tires. Run the door psi.

Earl

Being that his name is "big hips" I think its safe to assume a dually..............unless he has a huge arse.

To the OP, are you positive you aren't experiencing a front end "death wobble"? What makes you think its the rear end? Front end death wobble is very violent and is really the only one that happens (that I've ever heard of).

 

[EZeis]

Being that his name is "big hips" I think its safe to assume a dually..............unless he has a huge arse.

To the OP, are you positive you aren't experiencing a front end "death wobble"? What makes you think its the rear end? Front end death wobble is very violent and is really the only one that happens (that I've ever heard of).

I paid no attention to his name. I read the posts and pay no mind to names. I also avoid assuming, especially on forums. Maybe his old truck was a dually and that's the screen name? Maybe he loves ladies with big hips? Who knows.

But you bring up a good point that it maybe death wobble. He said the one time he couldn't steer the truck.


Earl

 

[Shiner]

……...death wobble on a truck with 12k on the clock would be most concerning.

 

[AH64ID]

I have an ‘18 with auto-level and dad has a ‘17 with auto-level. No issues on either of our rigs.

As others have asked, what’s your tire pressure?

Regular or Alt ride height?

What kind of payload?

 

[BIG HIPS 3500]

I should have been more detailed in my initial description of the issue (which intellectual mechanical sleuths need in order to give an informed opinion) which I love about this site and why I respect and appreciate the time that people give and the info that's shared by all of you...... Let's see if I can do a better job

-3500 dually 8' bed extended cab all tires (yes the crappy NEXON brand that came stock) inflated to psi recommendations on door
-heavy duty tow package 4:10 axle w/factory air suspension
-truck unloaded all 3 times issue occurred, and at random, impossible to predict
-approx. speed 50-65
-solid surface road
-NOT a series of bumps nor tractor trailer breaking bumps
-Severe and Violent axle "wrap or bounce" when I hit one sharp short bump, I'd say like 1.5" that definitely starts in the back and works its way up to the front (picture a tuning fork type action) which last time rendered my steering useless. Braking did not help, I was at the mercy of the truck until it decided it was done and lasted I'd say 10-12 seconds.
Now I have driven All types of trucks over the years I am a CDL-A holder and I drive many different types of commercial trucks in the Fire Service (I mention this only to stress that I'm not using the word VIOLENT lightly) The last time sacred the hell outa me. Like I won't let my wife or two boys drive the truck, which is totally unacceptable for a new truck. To be clear, Im not describing residual suspension hop from a stiff unloaded leaf pack.
I suspect the air bags are exaggerating this action. Maybe the system is OVER/UNDER inflated or a poor batch of leafs that rely too much on the air suspension, maybe the shocks are bad and are overwhelmed. Dodge says nothing noticeable, all is fine can't help because problem can't be duplicated

-only thing I know to do is to enlist my boys to rig up their GO-PRO cameras underneath, aiming at the axle and hope for the best

TFucili,I did as you suggested and called FCA today, I am also gonna write a letter and send it certified

so now that you all hopefully have a better picture....thoughts anyone??

 

[BIG HIPS 3500]

I have an ‘18 with auto-level and dad has a ‘17 with auto-level. No issues on either of our rigs.

As others have asked, what’s your tire pressure?

Regular or Alt ride height?

What kind of payload?

reg. height

 

[AH64ID]

Bad shocks are the first thing that comes to mind. Having driven a rig without shocks installed I experienced a similar outcome over bumps.

In reg height and no payload there is very little air in the bags, and IMO not enough to cause an issue. The system won’t adjust above a couple mph, so it shouldn’t be adding/subtracting air at those speeds.

Axle wrap is also unlikely at those speeds because of the lower torque being applied.

 

[AH64ID]

tractor trailer breaking bumps

Washboards?

That’s a term I haven’t heard before.