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08-20-2015, 08:27 PM
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#1
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Senior Member
Newmar Owners Club Winnebago Owners Club
Join Date: Dec 2010
Location: Golden, CO
Posts: 156
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2015 Cherokee severe front end wobbling when towed
During a just completed 700 mile trip the new 2015 Trailhawk Cherokee we were towing experienced severe frontend wobbling. In each case the wobbing was so severe it tossed the rear of our 36 ft County Coach. The wobbling started when I was making a turn that crossed a shallow drainage swale. Of course we were going slow but the wobbling continued until I was able to come to a stop; on re-starting all was OK.
I did a internet search on this issue and not to my surprise it has been reported numerous times on the FMCA and Cherokee Owners forums, and in each case the "cause" was similar circumstances. There are suggestions those experiencing this behavior should write the National Highway Traffic Safety Administration, which I will do. Those that have sought help from their Jeep dealer have apparently gotten no explanation nor solution. I for one am very unhappy as we bought this Cherokee specifically for towing behind our MH and I am now concerned it might be unsafe to do so.
BTW we are using a Blue Ox towing setup.
__________________
Russ and Anita
2016 Tiffin Allegro Bus 37AP SOLD
2022 Jeep Grand Cherokee Trailhawk 4XE (in tow...we hope)
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08-21-2015, 11:05 AM
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#2
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Senior Member
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 19,925
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Have you had alignment checked and made sure the toe-in is at the maximum recommended setting? Camber can also cause tracking issues, you want negative camber to make the wheels follow correctly.
__________________
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
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08-21-2015, 11:11 AM
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#3
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Senior Member
Join Date: Jul 2014
Posts: 35,349
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I did a internet search on this issue and not to my surprise it has been reported numerous times on the FMCA and Cherokee Owners forums, and in each case the "cause" was similar circumstances. There are suggestions those experiencing this behavior should write the National Highway Traffic Safety Administration, which I will do. Those that have sought help from their Jeep dealer have apparently gotten no explanation nor solution. I for one am very unhappy as we bought this Cherokee specifically for towing behind our MH and I am now concerned it might be unsafe to do so.
If you contact the National Highway Traffic Safety Administration, and they complain to Jeep, Jeep may just say "No 4 down towing "
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09-15-2015, 05:17 PM
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#4
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Senior Member
Winnebago Owners Club
Join Date: Sep 2013
Location: FTer Class of 2015 Origin: Evergreen, Colorado
Posts: 1,565
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Quote:
...In each case the wobbling was so severe it tossed the rear of our ... Coach. The wobbling started when I was making a turn that crossed a shallow drainage swale. Of course we were going slow but the wobbling continued until I was able to come to a stop; on re-starting all was OK...
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Coming into Denver this afternoon we experienced the same thing. It's more severe than a "wobble" in my opinion. In the rear camera, the TrailHawk appeared to be fighting to stay centered between the arms of the BlueOx tow bar. It started when I slowed to cross a dip in the road, and would not stop until I had slowed almost to a complete stop. It jerks the whole motorhome from-side-to-side. Very scary.
It's a new 2015 TrailHawk. Wonder if there has been any news on this issue? Time to hit the forums, I guess!
\ken
__________________
Ken, Deb, & Gadget (WIT Club, FMCA, SKP, and grateful volunteers with Habitat for Humanity and SOWERs), traveling in a well-behaved 2005 Winnebago Vectra 40FD w/1100w solar, some gee-golly-whizbang, and a TRAILERED 2015 Cherokee TrailHawk toad.
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09-15-2015, 05:29 PM
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#5
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Senior Member
Join Date: May 2013
Posts: 1,685
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Just a thought ... it could be a shock absorber gets stuck either extended or compressed. Corrects itself when the Jeep is allowed to come to rest. Cure could be as simple as a change to more robust shocks.
RVM 34
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09-16-2015, 07:58 AM
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#6
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Senior Member
Winnebago Owners Club
Join Date: Nov 2009
Posts: 827
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This topic has been beat to death, many of us have had no problems what so ever
I have towed mine almost 14,000 miles now
Here is the best answer out there
I have viewed the video of the “hunting” Jeep and that does not have any relationship with the phenomena called death wobble that is so common with solid front axle vehicles. I have experienced that and corrected several cases of it.
I have also experienced a much less severe case of what the video shows. In my case, the cause was excessive lateral movement of the draw bar inside the hitch receiver. The force vectors and theory are complex, though not as much as in true death wobble, and may be a waste of time to explain.
The towed vehicle will hunt side to side as a normal function of forward travel. External forces from wind and road surface irregularities assure that the vehicle will explore the limits that the hitch system will permit. The greater the lateral distance limit, the more energy developed that will be dumped into the hitch and thus the frame of the towing vehicle. The hitch assembly is a long lever and the fulcrum is the rear axle(s) assembly. The forces developed are transmitted all the way to the front axle of the towing vehicle.
The lateral forces generated are stored and released in a natural resonance determined by the mass and resiliency of the combined system. A low frequency oscillation is the result.
In my instance, I only needed to remove the lateral movement from the hitch with a “Quiet Hitch” from Road Master. I was lucky. I expect that most cases will not respond so easily. One may need to modify the towing vehicle with the addition of a rear track bar (pan hard rod), and / or experiment with tire pressure changes to modify the native resonant frequency.
You must accept the possibility that the two vehicles are not compatible in this configuration.
If the towed vehicle does not exhibit any instability when driven in a normal manner, then there is zero chance of any remedial attention from Jeep, and certainly no legal recourse.
Phil
__________________
2015 Itaska Reyo 25Q
2005 Jeep Wrangler Rubicon Towed (for the tuff trails)
2014 Jeep Wrangler Rubicon Towed (for tuffer stuff)
__________________
2012 Winnebago Journey 36M Cummins 360
2014 Jeep Cherokee Limited, 41 National Parks
501 Campgrounds, 2421 nights camping since 2009 and 109 K Winnebago miles
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09-16-2015, 02:23 PM
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#7
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Senior Member
Join Date: Dec 2014
Location: Georgia
Posts: 1,723
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Here is another perspective on this issue that was on another forum. It related to a similar issue with another vehicle, but also notes it seems to apply to the Jeep as well.
While this is not my post (I did ask the person who wrote this if it was ok to post here), it appears to be a logical consideration. I will also add this to the other similar thread.
Regards
The car is towable in all but a certain peculiar circumstance that causes the front wheels to oscillate left and right. That circumstance is when the toad vehicle is being turned left or right and the wheels have to roll over a dip or bump in the roadway at very low speeds. Such as entering a highway or turning a moderate sharp corner at very low speeds. As the wheels travel over the bump and turn at the same time there is a pronounced change in the alignment geometry called the included angle of turn. When the wheels begin to correct back to center there is not sufficient positive castor to keep the wheels from over correcting thus you get "Bump Steer".
This condition will not occur when the vehicle is under it's own power since the power steering is acting as a force damper to control the positioning of the front wheels.
It will also not happen under braking since the braking action of each wheel again acts as a force damper to control wheel movement.
The Ford Cmax is not the only vehicle to exhibit this condition, I believe the newer Jeep Cherokee models have this tendency as well as some Asian imports.
Hope this helps explain what's going on ....
__________________
D&S
2015 Tiffin Allegro 31SA; 24k chassis, Sumo springs
2015 Jeep Cherokee Trailhawk
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09-16-2015, 02:34 PM
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#8
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Senior Member
Monaco Owners Club Workhorse Chassis Owner
Join Date: Aug 2002
Location: Clovis, CA, USA
Posts: 13,103
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__________________
2004 Monaco La Palma 36DBD, W22, 8.1, 7.1 MPG
2000 LEXUS RX300 FWD 22MPG 4020 LBS
Criticism is easier than Craftsmanship
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09-16-2015, 02:41 PM
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#9
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Senior Member
Join Date: Dec 2014
Location: Georgia
Posts: 1,723
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Quote:
Originally Posted by Arch Hoagland
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Arch, I noted I would post the above on both threads since they have kind of morphed into the same tropic.
Regards.
__________________
D&S
2015 Tiffin Allegro 31SA; 24k chassis, Sumo springs
2015 Jeep Cherokee Trailhawk
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09-17-2015, 07:49 PM
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#10
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Senior Member
Winnebago Owners Club
Join Date: Sep 2013
Location: FTer Class of 2015 Origin: Evergreen, Colorado
Posts: 1,565
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Quote:
I have viewed the video of the “hunting” Jeep ... and experienced a much less severe case of what the video shows. In my case, the cause was excessive lateral movement of the draw bar inside the hitch receiver. The force vectors and theory are complex, though not as much as in true death wobble, and may be a waste of time to explain.
The towed vehicle will hunt side to side as a normal function of forward travel. External forces from wind and road surface irregularities assure that the vehicle will explore the limits that the hitch system will permit. The greater the lateral distance limit, the more energy developed that will be dumped into the hitch and thus the frame of the towing vehicle. The hitch assembly is a long lever and the fulcrum is the rear axle(s) assembly. The forces developed are transmitted all the way to the front axle of the towing vehicle.
The lateral forces generated are stored and released in a natural resonance determined by the mass and resiliency of the combined system. A low frequency oscillation is the result.
In my instance, I only needed to remove the lateral movement from the hitch with a “Quiet Hitch” from Road Master. I was lucky. I expect that most cases will not respond so easily.
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Phil: Thank you for the feedback. I will try the "Quiet Hitch" strategy and report back. I greatly appreciate your help.
\ken
__________________
Ken, Deb, & Gadget (WIT Club, FMCA, SKP, and grateful volunteers with Habitat for Humanity and SOWERs), traveling in a well-behaved 2005 Winnebago Vectra 40FD w/1100w solar, some gee-golly-whizbang, and a TRAILERED 2015 Cherokee TrailHawk toad.
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09-18-2015, 07:24 AM
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#11
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Senior Member
Newmar Owners Club Winnebago Owners Club
Join Date: Dec 2010
Location: Golden, CO
Posts: 156
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Quote:
Originally Posted by Betr2Trvl
Here is another perspective on this issue that was on another forum. It related to a similar issue with another vehicle, but also notes it seems to apply to the Jeep as well.
While this is not my post (I did ask the person who wrote this if it was ok to post here), it appears to be a logical consideration. I will also add this to the other similar thread.
Regards
The car is towable in all but a certain peculiar circumstance that causes the front wheels to oscillate left and right. That circumstance is when the toad vehicle is being turned left or right and the wheels have to roll over a dip or bump in the roadway at very low speeds. Such as entering a highway or turning a moderate sharp corner at very low speeds. As the wheels travel over the bump and turn at the same time there is a pronounced change in the alignment geometry called the included angle of turn. When the wheels begin to correct back to center there is not sufficient positive castor to keep the wheels from over correcting thus you get "Bump Steer".
This condition will not occur when the vehicle is under it's own power since the power steering is acting as a force damper to control the positioning of the front wheels.
It will also not happen under braking since the braking action of each wheel again acts as a force damper to control wheel movement.
The Ford Cmax is not the only vehicle to exhibit this condition, I believe the newer Jeep Cherokee models have this tendency as well as some Asian imports.
Hope this helps explain what's going on ....
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This comment touches on what I think is the heart of the problem--the Cherokees power steering. This particular vehicle has what I understand to be a new electronic power steering system. According to Jeep--
Without the normal resistance of hydraulic pressures in the steering system perhaps the front is simply too loose to track properly. And once it wobbles one direction it will try to re-center but rebound too far in the other direction...and so forth.
Contrary to those who think alignment is the issue, there is not camber or caster adjustment on the "A speed-sensitive electronic power steering system helps improve efficiency and reduces road noise. The system automatically adjusts for limited effort during parking or increased steering effort on the road"
Cherokee. Assuming the pre-programmed camber and castor are similar to the Grand's and other vehicles with great history as flat-towed vehicles, this new system may be the culprit.
And by the way I have the Quiet Hitch so looseness there is not the issue.
__________________
Russ and Anita
2016 Tiffin Allegro Bus 37AP SOLD
2022 Jeep Grand Cherokee Trailhawk 4XE (in tow...we hope)
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09-18-2015, 08:08 AM
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#12
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Senior Member
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 19,925
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Quote:
Originally Posted by colo.kids
This comment touches on what I think is the heart of the problem--the Cherokees power steering. This particular vehicle has what I understand to be a new electronic power steering system. According to Jeep--
Without the normal resistance of hydraulic pressures in the steering system perhaps the front is simply too loose to track properly. And once it wobbles one direction it will try to re-center but rebound too far in the other direction...and so forth.
Contrary to those who think alignment is the issue, there is not camber or caster adjustment on the "A speed-sensitive electronic power steering system helps improve efficiency and reduces road noise. The system automatically adjusts for limited effort during parking or increased steering effort on the road"
Cherokee. Assuming the pre-programmed camber and castor are similar to the Grand's and other vehicles with great history as flat-towed vehicles, this new system may be the culprit.
And by the way I have the Quiet Hitch so looseness there is not the issue.
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Power steering, whether electric, electronic, or hydraulic has little to do with tracking issues. Alignment has everything to do with tracking and handling. Caster angle is most influential, then toe in, then the least is camber angle. None is adjusted by power steering, all is adjusted by various methods, from adjusting tie rods, adding/deleting spacers, to actually bending components to adjust angles.
Since the late 1890's, most cars use positive castor to improve self-centering, tracking, and reduce wander. In an extreme example, the wobble in a shopping cart wheel is caused by extreme negative castor which causes the wheel to oscillate.
Toe in, or the tires being slightly angled to track towards the center also improves tracking and reduces wander due to road imperfections.
Camber, or the top of the wheel not being exactly 90º relative to the straight ahead travel, has more to do with tire wear, cornering and handling under it's own power, not towing.
Another issue not mentioned might be tire inflation. Low pressure tires would allow more bounce and continue the oscillation after a dip on a turn started it.
If all the above are within correct measure, I wonder, has anyone tried adding a steering damper?
__________________
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
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09-18-2015, 03:23 PM
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#13
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Senior Member
Newmar Owners Club Winnebago Owners Club
Join Date: Dec 2010
Location: Golden, CO
Posts: 156
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For some reason the quote from Jeep got left off my previous posts. Here it is''
"*A speed-sensitive electronic power steering system helps improve
efficiency and reduces road noise. The system automatically adjusts for
limited effort during parking or increased steering effort on the road"*
__________________
Russ and Anita
2016 Tiffin Allegro Bus 37AP SOLD
2022 Jeep Grand Cherokee Trailhawk 4XE (in tow...we hope)
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09-18-2015, 03:27 PM
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#14
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Senior Member
Newmar Owners Club Winnebago Owners Club
Join Date: Dec 2010
Location: Golden, CO
Posts: 156
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Quote:
Originally Posted by BFlinn181
Power steering, whether electric, electronic, or hydraulic has little to do with tracking issues. Alignment has everything to do with tracking and handling. Caster angle is most influential, then toe in, then the least is camber angle. None is adjusted by power steering, all is adjusted by various methods, from adjusting tie rods, adding/deleting spacers, to actually bending components to adjust angles.
Since the late 1890's, most cars use positive castor to improve self-centering, tracking, and reduce wander. In an extreme example, the wobble in a shopping cart wheel is caused by extreme negative castor which causes the wheel to oscillate.
Toe in, or the tires being slightly angled to track towards the center also improves tracking and reduces wander due to road imperfections.
Camber, or the top of the wheel not being exactly 90º relative to the straight ahead travel, has more to do with tire wear, cornering and handling under it's own power, not towing.
Another issue not mentioned might be tire inflation. Low pressure tires would allow more bounce and continue the oscillation after a dip on a turn started it.
If all the above are within correct measure, I wonder, has anyone tried adding a steering damper?
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Folks are missing the point. Caster and camber are NOT adjustable on this vehicle. There might be some fixes to this issue, but the point here is NHTSB and Jeep need to be aware of this issue before this behavior causes are serious traffic accident or causes damages to either the TOAD (Cherokee) or MH.
__________________
Russ and Anita
2016 Tiffin Allegro Bus 37AP SOLD
2022 Jeep Grand Cherokee Trailhawk 4XE (in tow...we hope)
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