Rockwell Posted October 9, 2015 Share Posted October 9, 2015 Hello,So im cruising down the interstate in my new (new to me) 2011 Pinnacle (230 WB w/sleeper) and 53' dry van empty. Im running about 68mph when I see 2 potholes ahead of me, one to the left, one to the right. With limited time, I offset the rigs path to avoid the left pothole, but wind up clipping the other pothole with my right front runner.BAM! I feel the inital and thunderous pound of the pothole, then, the whole rig begins to shake, vibrate, and shutter with alarming force as if Im loosing my front runner. I immediatley let off the throttle, and apply no brakes. As my speed naturally decreases I put the flashers on and begin to bail for the shoulder. 60 mph, 50, 40, 30, and then at about 20mph the rig stabilizes. I complete the stop, get out and check everything. All looks fine, nice and tight.I merge back onto the intserstate and all is well. As I gain confidence, I bring the rig back up to about 70mph. The rest of the day it rides smooth as silk. No vibrations and no problems going over bumps, seams, steel plates, or ruts.What could this be? Bad or weak shock?The truck does have an air ride steer axle. I have no experience with air ride steer axle setups. Having purchased this truck very recently, the chassis was freshly painted by the dealer so its tough to see the "true" condition of things like the shocks.Any ideas?FYI, the interstate I speak of is I-80 in New Jersey, need I say more. Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/ Share on other sites More sharing options...
thomastractorsvc Posted October 9, 2015 Share Posted October 9, 2015 How is the front tire balanced? Are you using something like the centramatic? http://www.gpartsinc.com/p-5756-centramatic-600-650-auto-wheel-balancer-for-245-wheel-steer-axle.aspx?CAGPSPN=pla&catargetid=330001590000006397&cadevice=c&gclid=Cj0KEQjwy92wBRCl7trx4PaIo8EBEiQASPhtC1m4XlJZ4X7ArN5RzNFou6UEpkssqXosttASldxKto0aAggy8P8HAQIf so could have shocked it and took a few minutes to settle back. Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306755 Share on other sites More sharing options...
eddeere Posted October 9, 2015 Share Posted October 9, 2015 Just a question did the ABS light come on ? Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306761 Share on other sites More sharing options...
Rockwell Posted October 9, 2015 Author Share Posted October 9, 2015 Thomas, No centramatic or similar is being used. Now I cant say for certain if balancing beads are inside the tire, thats possible. Very good thought!Eddeere, No ABS light. No warning lights whatsoever.Thanks! Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306763 Share on other sites More sharing options...
thomastractorsvc Posted October 9, 2015 Share Posted October 9, 2015 I suppose the beads could do the same if it hit hard Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306774 Share on other sites More sharing options...
Rockwell Posted October 9, 2015 Author Share Posted October 9, 2015 I don't know if there are beads inside or not as I just purchased truck.Ya think a weak shock could be the culprit? Not a completely blown shock, just weak? Maybe that would explain why the truck rides fine all of the time and this one big hit sent the front wheel into an up/down motion that the front shock could not resist? Could the shock be strong enough to handle normal abuse, but weak enough to not withstand a larger impact? Possible? Other than beads (which is a great thought) this is the only theory I can come up with.If it happened once, I have to assume it will again and I don't look forward to it. Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306777 Share on other sites More sharing options...
mrsmackpaul Posted October 9, 2015 Share Posted October 9, 2015 I wonder if like a 4x4 that have the steering damper to stop the wheels flopping from side to side if hitting the pot hole just on the edge some induced the very thing that happens on a 4x4 that has the damper to stop it happening Im not sure why 4x4's need these and trucks dont Im just having guess I have no idea on any of this stuffPaul Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306791 Share on other sites More sharing options...
RedBullDog Posted October 9, 2015 Share Posted October 9, 2015 When you get a chance, take the front wheel that hit the hole off of the truck. Check the wheel for cracks around the bolt holes. While the wheel is off, check out the hub for end play and the tierod head for slack. May all be fine, but that would rule out most of the major stuff. Also i guess it could have broke a belt in the steer tire. Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306800 Share on other sites More sharing options...
thomastractorsvc Posted October 9, 2015 Share Posted October 9, 2015 I doubt it is a broken belt if it stopped wobbling, usually will bulge and get worse .I was thinking you should check the lug nuts if it is stud pilot the studs are smaller than the holes in the rim maybe when it hit it could have off centered the rim on the hub and as you drove it it re-centered? They sell special centering bushings to help prevent wear and things like this. http://www.spcalignment.com/component/content/article/45-subpages/heavy-duty/288-wheel-centering-products Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306802 Share on other sites More sharing options...
IH Farms 2 Posted October 10, 2015 Share Posted October 10, 2015 My experience with air ride steer axles is that's a pretty common. If it is a fabricated axle you may want to check the kingpins Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-306862 Share on other sites More sharing options...
Rockwell Posted October 11, 2015 Author Share Posted October 11, 2015 Firstly, THANK YOU ALL for the help and response!I hadn't noticed this while on the side of the road but I now see this truck has a Steering Damper on it. I guess that's due to the air ride axle. I'm most likely going to change that out for a new one at some point if it occurs again. Hopefully I just hit the "mothership" of all potholes and it was a one time event.I did learn I have the Hendrickson Airtek system. For anyone else that might have the same, Hendrickson has lots of info on their site including diagrams and part numbers for specific makes/models of trucks. Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-307086 Share on other sites More sharing options...
Super Duty John Posted October 11, 2015 Share Posted October 11, 2015 Hello,So im cruising down the interstate in my new (new to me) 2011 Pinnacle (230 WB w/sleeper) and 53' dry van empty. Im running about 68mph when I see 2 potholes ahead of me, one to the left, one to the right. With limited time, I offset the rigs path to avoid the left pothole, but wind up clipping the other pothole with my right front runner.BAM! I feel the inital and thunderous pound of the pothole, then, the whole rig begins to shake, vibrate, and shutter with alarming force as if Im loosing my front runner. I immediatley let off the throttle, and apply no brakes. As my speed naturally decreases I put the flashers on and begin to bail for the shoulder. 60 mph, 50, 40, 30, and then at about 20mph the rig stabilizes. I complete the stop, get out and check everything. All looks fine, nice and tight.I merge back onto the intserstate and all is well. As I gain confidence, I bring the rig back up to about 70mph. The rest of the day it rides smooth as silk. No vibrations and no problems going over bumps, seams, steel plates, or ruts.What could this be? Bad or weak shock?The truck does have an air ride steer axle. I have no experience with air ride steer axle setups. Having purchased this truck very recently, the chassis was freshly painted by the dealer so its tough to see the "true" condition of things like the shocks.Any ideas?FYI, the interstate I speak of is I-80 in New Jersey, need I say more.One of the worst roads in America! I used to haul there in a roll off Autocar back in the 80's, many times I thought I lost a box! Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-307095 Share on other sites More sharing options...
Quickfarms Posted October 12, 2015 Share Posted October 12, 2015 Worst roads New Jersey or Los Angeles. New Jersey wins on old and poor design. It is a tie for lack of maintenance. Quote Link to comment https://www.bigmacktrucks.com/topic/42122-pothole-sudden-severe-deathwobble/#findComment-307175 Share on other sites More sharing options...
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