Nixie 0 Posted July 3, 2013 Report Share Posted July 3, 2013 We just recently purchased a Keystone Outback 21rs. Dry weight of this camper is 4,500ish. GVWR of the camper is 6500. It is 22ft long closed up. We are currently towing it with a GMC Yukon that has a tow capacity of 7,600, GCVWR of 13,000, GVWR is 6,900 .We did take the camper to the CAT scales before our first journey. The whole rig weighed in at 12,300. Our car weighed in at 6,300. The Camper 5,700. Everything came in under what it should, but it is close. My first question: Is that to close?? We had a little problem on the drive. The camper wasn't swaying. But we were having a problem with what I guess is called "harmonic bounce". It only happened on a few highways in Michigan. The Yukon would go over some spots and would start bouncing and then camper would start doing it. We couldn't get it to stop unless we sped up a little bit or pumped the trailer brakes. My second question: Is this normal? What can we do to prevent this from happening again? We do have the Equalizer WDH with the 1000 bars. The only reason why I am asking all of these is we are really considering towing our camper to Disney in April. We live in Indiana. It would be a 17+ hour journey. We would have to go through all the hills in KY and TN. My third question: Do you think the Yukon will be able to handle that? Thanks in advance for all your help!! Quote Link to post Share on other sites
BradyBzLyn...Mo 2,023 Posted July 3, 2013 Report Share Posted July 3, 2013 I'll let the resident experts in such things answer your questions. Just wanted to say... :welcrowd: Quote Link to post Share on other sites
Discamper 394 Posted July 3, 2013 Report Share Posted July 3, 2013 Maybe this can help you. Your vehicles towing capacity is based on driver only with no cargo and a quarter tank of fuel on flat pavement. Quote Link to post Share on other sites
CKCK 45 Posted July 3, 2013 Report Share Posted July 3, 2013 maybe this can help you. Hey beautiful towing capacity is based on driver only with with no cargo quarter tank of fuel on flat pavement Hey beautiful? :heart: :rofl2: Quote Link to post Share on other sites
mouseketab.....Carol 1,261 Posted July 3, 2013 Report Share Posted July 3, 2013 That's true, but the GCVWR is below maximum, and the GVWR is below maximum. You are definitely below all weight levels. There are some folks that feel you should be like only 60% of your maximums in all levels. I don't have a lot of vehicle knowledge, but perhaps it's shocks on your tow vehicle or on your camper? Quote Link to post Share on other sites
Discamper 394 Posted July 3, 2013 Report Share Posted July 3, 2013 Hey beautiful? :heart: :rofl2:That is what happens went you talk text and someone else talks Quote Link to post Share on other sites
Nixie 0 Posted July 3, 2013 Author Report Share Posted July 3, 2013 My suspension is the Air Ride suspension which is pretty much air bags all around the vehicle. Quote Link to post Share on other sites
BradyBzLyn...Mo 2,023 Posted July 3, 2013 Report Share Posted July 3, 2013 The Yukon would go over some spots and would start bouncing and then camper would start doing it. We couldn't get it to stop unless we sped up a little bit or pumped the trailer brakes. My second question: Is this normal? What can we do to prevent this from happening again? We do have the Equalizer WDH with the 1000 bars. Asked DH (he's my own personal resident expert) and here's what he said... Tongue weight may be too little, resulting in the trailer "picking up" the back of the truck. You may need to adjust the weight distribution bars to increase the tongue weight. Other possibility is that you need a heavier duty rear shock on the truck. Quote Link to post Share on other sites
ftwildernessguy 778 Posted July 3, 2013 Report Share Posted July 3, 2013 I have a 2009 Outback 210rs. I tow with a 2005 Ford f150 with a tow rating of 9300 lbs. Do I think you are too close with the trailer weight? All I will say is I would not feel real warm and fuzzy about towing that close. Anyway, I agree with Mo's hubby re. the tongue weight. Be sure when you pack your trailer you pack heavier in front. Properly adjusted, the WDH should distribute the weight so that if you look at the trailer and TV from the side, you can draw a straight line from the back bumper of the trailer to the front bumper of your truck. 1000 lb bars are pretty tight considering the tongue weight of this trailer should be around 600 lbs. I will try to find a link to an article about WDH spring bars that explains everything really well. I think if you can tweak the hitch you will be better off. WWLD? Quote Link to post Share on other sites
doodlebug....Cherie 461 Posted July 3, 2013 Report Share Posted July 3, 2013 I don't have any answers for you either but also wanted to say Where in Michigan are you? I am on the Saginaw Bay. Quote Link to post Share on other sites
ftwildernessguy 778 Posted July 3, 2013 Report Share Posted July 3, 2013 Here is that article:http://home.hiwaay.net/~tomorkim/Reese.htm Quote Link to post Share on other sites
BouncingTiggers 98 Posted July 3, 2013 Report Share Posted July 3, 2013 I'm curious as to what is causing the bounce also. Our last trailer did that & I could never track it down. Tongue weight was what I thought caused it at the time. Nothing ever seemed to make it go away completely though. Since we upgraded campers though it has never come back. One thing I have found is that to much air in my rear airbags causes our current one to bounce. Quote Link to post Share on other sites
ftwildernessguy 778 Posted July 3, 2013 Report Share Posted July 3, 2013 I have, on one or two occasions, had the harmonic bounce issue. It has occurred when there are expansion joints spaced just right on the pavement so the truck hits them in sync with the trailer. Annoying as hell, but a civil engineering issue and nothing that I could correct. Quote Link to post Share on other sites
Andrew Roberts 17 Posted July 3, 2013 Report Share Posted July 3, 2013 where in Indiana are you from South Bend here. And maybe add air ride to the rear of the yukon. I bet it would smooth out fine Quote Link to post Share on other sites
Nixie 0 Posted July 3, 2013 Author Report Share Posted July 3, 2013 where in Indiana are you from South Bend here. And maybe add air ride to the rear of the yukon. I bet it would smooth out fine We are from Ft. Wayne, Indiana. Quote Link to post Share on other sites
Andrew Roberts 17 Posted July 7, 2013 Report Share Posted July 7, 2013 Thats cool love to find fiends in my state Quote Link to post Share on other sites
disney4dan 68 Posted July 9, 2013 Report Share Posted July 9, 2013 I'm curious as to what is causing the bounce also. Our last trailer did that & I could never track it down. Tongue weight was what I thought caused it at the time. Nothing ever seemed to make it go away completely though. Since we upgraded campers though it has never come back. One thing I have found is that to much air in my rear airbags causes our current one to bounce. I have, on one or two occasions, had the harmonic bounce issue. It has occurred when there are expansion joints spaced just right on the pavement so the truck hits them in sync with the trailer. Annoying as hell, but a civil engineering issue and nothing that I could correct. This happened to us on our way back from the Fort in 2008 when we decided to take I-76 East in Pennsylvania instead of our usual I-81 to I-84. I am confident that I had the right tongue weight because I used a scale to check before we left Orlando and discovered there that it was too light and I agree with Jim that it seems to be just an unfortunate issue of spacing in the expansion cracks. The fact that it went away at speeds either below 45 or greater than 75 seems to prove that point, changes the time between the truck responding to the bounce and then the trailer responding. So of course I did the right thing and slowed to 40 mph on the highway because I would NEVER think of breaking the law and driving at around 80 :rofl3: Quote Link to post Share on other sites
Helmsey......Todd 134 Posted July 9, 2013 Report Share Posted July 9, 2013 I would think that tongue weight could be playing a part in the bouncing you are getting. To know for sure if you have proper weight distribution you will need to head back to the scales all loaded up and get 2 different weights; first will be with the trailer hooked up without weight distribution bars, and then you will need just the yukons weightWith those 2 weights you will be able to tell how much your tongue weight is by taking the gross vehicle weight of the yukon from the first weigh and subtract the gross vehicle weight of just the yukon. If I remember correctly that will give you the tongue weight that you have for your trailer.You are looking to get 10 - 15 percent of the trailers weigh to the tongue, so from your numbers you would want at least 570lbs of tongue weight and could have as much as 855lbs. Hope this helps some. Quote Link to post Share on other sites
Nixie 0 Posted July 19, 2013 Author Report Share Posted July 19, 2013 We "may" have found the cause of the harmonic bounce issue. Supposedly, our air ride shocks in the back are bad. This is according to a visual inspection when I had the tires replaced last week. They said my shocks looked "corroded". (Well duh I live in Indiana; a winter time salt lovin' state). What they did not do is actually have the car on when it was jacked up to see if the actual bags were leaking or if the compresser was constantly running as it would be if there was a leak. If they are blown, it makes total sense why we were having problems. I am taking the vehicle to another shop for a second opinion before I spend all the money to have those shocks replaced. Quote Link to post Share on other sites
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