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Bent Axles/Camber Issues

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Forum Name: Podmods, Maintenance, Tips and Tricks
Forum Discription: Ask maintenance questions, share your podmods (modifications) and helpful tips
URL: http://www.rpod-owners.com/forum_posts.asp?TID=12826
Printed Date: 06 May 2024 at 12:08am
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Topic: Bent Axles/Camber Issues
Posted By: mcarter
Subject: Bent Axles/Camber Issues
Date Posted: 08 May 2019 at 4:51pm
Interested in idea of how many owners of Pods have experienced axle issues, and if that axle was a Dexter or a Lippert. The fix or mod is not so important as the regularity of axle failure and what axle you experienced it with. Thanks

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Mike Carter
2015 178
" I had the right to remain silent, I just didn't have the ability."



Replies:
Posted By: StephenH
Date Posted: 08 May 2019 at 5:17pm
I think you already know my answer. You might want to see if you can turn this into a poll.

Mine was Lippert, replaced after it lost its camber after our big trip last year.


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StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: offgrid
Date Posted: 08 May 2019 at 5:26pm
Its not my poll so this is just a suggestion. Ideally we would get everyone who reads this topic to vote, whether they have had a problem or not, that way we could start to get at the percent of folks who have had problems in general and with each axle type. For example, if there are 10x as many rPods with Lippert axles as Dexters, having 10x as many Lippert failures wouldn't be at all surprising. Just a thought...

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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: marwayne
Date Posted: 08 May 2019 at 5:29pm
I had a Dexter axle, But as I found out at the rally in Goshen it was only rated at 3000#. FR replaced it with a 3500# Lippert Axle. Both lost the camber. That is why I went through all this trouble.
 


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If you want something done right, do it yourself.
2011 RP172, 2016 Tundra 5.7 Litre, Ltd.




Posted By: SC for Huskers
Date Posted: 08 May 2019 at 6:13pm
2017 R172   Lippert


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Happy Traveling,
Tom
2017 172pod
2011 F150 STX


Posted By: mcarter
Date Posted: 08 May 2019 at 9:29pm
Offgrid,

Good suggestion.

SH,

It is a poll.

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Mike Carter
2015 178
" I had the right to remain silent, I just didn't have the ability."


Posted By: furpod
Date Posted: 09 May 2019 at 7:06am
No option for "no issues"... Ouch

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Posted By: StephenH
Date Posted: 09 May 2019 at 8:03am
Originally posted by mcarter

Offgrid,

Good suggestion.

SH,

It is a poll.
The poll option was added after my first response suggesting it. It wasn't there at first.


-------------
StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: Wood River Pod
Date Posted: 09 May 2019 at 9:37am
Lippert on my '17 green 179 HR. No issues to date...but I'm waiting.

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Smith's in Hailey
Early 2017 179 HRE

http://www.rpod-owners.com/forum_posts.asp?TID=9134&PN=1&title=wood-river-179-mods - Wood River Mods


Posted By: TheBum
Date Posted: 09 May 2019 at 9:58am
Lippert, RP-179, no issues.

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Alan
2022 R-Pod 196 "RaptoRPod"
2022 Ram 1500 Lone Star 4x4
Three cats


Posted By: TheBum
Date Posted: 09 May 2019 at 9:59am
Originally posted by furpod

No option for "no issues"... Ouch


The poll should have had four options: Lippert, no issues; Lippert with issues; Dexter, no issues; and Dexter with issues.

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Alan
2022 R-Pod 196 "RaptoRPod"
2022 Ram 1500 Lone Star 4x4
Three cats


Posted By: mcarter
Date Posted: 09 May 2019 at 5:10pm
That's fair Bum. I wasn't concerned about no issues. I was looking at axles with issues and what type they were. I suspect that more owners have Lippert's than Dexter's but that is an assumption. I have a Dexter that has no issues. I could have been more selective in poll options, but it is what it is.

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Mike Carter
2015 178
" I had the right to remain silent, I just didn't have the ability."


Posted By: Blender Bob
Date Posted: 09 May 2019 at 7:38pm
So what does one have to do to bend an axle?  I have a 2018 178 HRE and we do go on some rough roads in BLM land.

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Bob
2015 Chevy Colorado Z71
2018 178 R-pod Hood River Edition


Posted By: StephenH
Date Posted: 09 May 2019 at 9:29pm
It isn't something you "do" as such, it is something that happens. We were on the homeward bound side of our trip so the black and gray tanks probably had at least half each by that point. It is likely that when we hit those really rough roads in Illinois, the additional water weight combined with the bouncing of the trailer on those roads was too much for the axle to handle. Since we did not have an opportunity to weigh it at that point, I could not tell you how close to the 3500 lb limit we were at that point. After that trip was when I started noticing the camber of the wheels was off but it was not until after we went to the Kentucky Mini-Mini that we got it to the dealer for service and repair. By that time, the wear on the inside edge was obvious.

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StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: SC for Huskers
Date Posted: 10 May 2019 at 12:22am
In my case, I think it was putting  about 800 pounds of stuff in the back of the pickup, loading the RV with everything I need for two weeks, and then adding the "Weight Distribution Equalizer sway control"  bars on. They transferred a lot of the pickup load to the RV axle.  Then drove from SC to SD and back. At least everything was level.


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Happy Traveling,
Tom
2017 172pod
2011 F150 STX


Posted By: offgrid
Date Posted: 10 May 2019 at 6:46am
From my calcs it would take a momentary peak load of about 3500 lbs on either wheel (or 7000 lbs on both wheels) to bend a Lippert axle tube on an rPod. That can readily happen if you have a trailer axle loaded at or near 3500 lbs (1750 lbs per side with or without a wdh) and then hit a pot hole, curb, or speed bump hard. 

From what I've read, vehicles need to have more like a 3x or higher load factor over their rating in order to avoid bending something eventually. Lippert rPod axles are at about a 2x load factor. 

I'm (almost, not quite) tempted to get one of these, strap it to my axle, connect it to a laptop, and use it to record actual g loads. If it came with an iphone app I'd probably try it. 

https://www.amazon.com/dp/B01N99BUMR/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B01N99BUMR&pd_rd_w=IKvTz&pf_rd_p=46cdcfa7-b302-4268-b799-8f7d8cb5008b&pd_rd_wg=UtZuU&pf_rd_r=DTDAW0XZ70S95E93DRFQ&pd_rd_r=0a7c8ced-7316-11e9-88ae-891106fe0638 - https://www.amazon.com/dp/B01N99BUMR/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B01N99BUMR&pd_rd_w=IKvTz&pf_rd_p=46cdcfa7-b302-4268-b799-8f7d8cb5008b&pd_rd_wg=UtZuU&pf_rd_r=DTDAW0XZ70S95E93DRFQ&pd_rd_r=0a7c8ced-7316-11e9-88ae-891106fe0638


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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: offgrid
Date Posted: 10 May 2019 at 7:19am
mcarter or any others with Dexter axles, are your axles 3 inch box tubes? In a diamond or flat configuration? Can you measure the tube wall thickness? 

Drawings on the Dexter website appear to show a flat box tube orientation which would add significant strength. Assuming the tube sections are the same dimensions from both manufacturers, that alone could be reason enough to change to a Dexter if you have a failed Lippert axle. 


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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: StephenH
Date Posted: 10 May 2019 at 9:50am
Originally posted by offgrid

From my calcs it would take a momentary peak load of about 3500 lbs on either wheel (or 7000 lbs on both wheels) to bend a Lippert axle tube on an rPod. That can readily happen if you have a trailer axle loaded at or near 3500 lbs (1750 lbs per side with or without a wdh) and then hit a pot hole, curb, or speed bump hard. 

From what I've read, vehicles need to have more like a 3x or higher load factor over their rating in order to avoid bending something eventually. Lippert rPod axles are at about a 2x load factor. 

I'm (almost, not quite) tempted to get one of these, strap it to my axle, connect it to a laptop, and use it to record actual g loads. If it came with an iphone app I'd probably try it. 

https://www.amazon.com/dp/B01N99BUMR/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B01N99BUMR&pd_rd_w=IKvTz&pf_rd_p=46cdcfa7-b302-4268-b799-8f7d8cb5008b&pd_rd_wg=UtZuU&pf_rd_r=DTDAW0XZ70S95E93DRFQ&pd_rd_r=0a7c8ced-7316-11e9-88ae-891106fe0638 - https://www.amazon.com/dp/B01N99BUMR/ref=sspa_dk_detail_4?psc=1&pd_rd_i=B01N99BUMR&pd_rd_w=IKvTz&pf_rd_p=46cdcfa7-b302-4268-b799-8f7d8cb5008b&pd_rd_wg=UtZuU&pf_rd_r=DTDAW0XZ70S95E93DRFQ&pd_rd_r=0a7c8ced-7316-11e9-88ae-891106fe0638
That is likely what happened then.

I looked at those and saw that there were less expensive ones that did not have a housing. I don't know if any of them are made to withstand the conditions under the R-Pod as it is going down the road, especially if it is raining. If that is the case, this one would likely work since it is also Bluetooth and you could put it in a waterproof container strapped to the axle with a battery to power it. If you had a laptop with Bluetooth or a Bluetooth dongle, that would work.
https://www.amazon.com/Accelerometer-Triple-Axis-Acceleration-Transducer-BWT61/dp/B018NL1R0Y/ - https://www.amazon.com/Accelerometer-Triple-Axis-Acceleration-Transducer-BWT61/dp/B018NL1R0Y/

I am going to see if I can get up with a local supplier for the angle to strap to my axle before we take it out. I don't want to encounter a situation where I could end having to do another expensive axle replacement.


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StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: texman
Date Posted: 10 May 2019 at 10:05am
not sure i understand all of this.
  1. are the axles bending outbound of frame between wheel and frame?
  2. losing the camber at the center?
  3. or both?

if just the camber at the center, then couldn't the trailer be jacked up and put on stands at frame next to wheels and apply a jack to center of axle to return some camber?  

If outbound of frame, then why support the center of the axle?  Confused


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TexMan 2015 182g
2018 Sequoia
http://www.rpod-owners.com/forum_posts.asp?TID=9122&title=texman-182g-mods - TexManMods


Posted By: GlueGuy
Date Posted: 10 May 2019 at 10:18am
Originally posted by texman

not sure i understand all of this.
  1. are the axles bending outbound of frame between wheel and frame?
  2. losing the camber at the center?
  3. or both?

if just the camber at the center, then couldn't the trailer be jacked up and put on stands at frame next to wheels and apply a jack to center of axle to return some camber?  

If outbound of frame, then why support the center of the axle?  Confused 
I think the bend is happening at the attach point-outward from the frame. The camber change is a symptom of the bend, and not the main issue.

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bp
2017 R-Pod 179 Hood River
2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost


Posted By: StephenH
Date Posted: 10 May 2019 at 10:59am
The axle I had replaced did not have any visual bend at the attachment points but the camber of the tires was off with the tires splayed out at the bottoms and wearing the inside edge of the tires. That being said, adding some form of reinforcement to the outboard sides is critical to addressing the problem, whether the full-length V channel or either of the two outboard reinforcements.


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StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: marwayne
Date Posted: 10 May 2019 at 11:51am
If you jack up the axle in the middle you come to a point where you just lift the pod, release the jack the axle the goes back to where it was.

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If you want something done right, do it yourself.
2011 RP172, 2016 Tundra 5.7 Litre, Ltd.




Posted By: mcarter
Date Posted: 10 May 2019 at 5:01pm
Off Grid,

I will check and reply.

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Mike Carter
2015 178
" I had the right to remain silent, I just didn't have the ability."


Posted By: Toyanvil
Date Posted: 10 May 2019 at 7:47pm
I think the numbers in the poll will not tell us if the Dexter axle is better if we don't know the percentage of Dexter to Lippert axle were installed on RPODs.


Posted By: marwayne
Date Posted: 10 May 2019 at 8:54pm
I had both Dexter and Lippert fail, however the Dexter was only rated at 3000#.

-------------
If you want something done right, do it yourself.
2011 RP172, 2016 Tundra 5.7 Litre, Ltd.




Posted By: offgrid
Date Posted: 11 May 2019 at 3:50am
Originally posted by texman

not sure i understand all of this.
  1. are the axles bending outbound of frame between wheel and frame?
  2. losing the camber at the center?
  3. or both?

if just the camber at the center, then couldn't the trailer be jacked up and put on stands at frame next to wheels and apply a jack to center of axle to return some camber?  

If outbound of frame, then why support the center of the axle?  Confused

All 3 depending on what kind of bump load you have.  The way the bending forces work on the axle tube which is a cantilever, you can have two cases. 

Case 1) If you hit say a speed bump with both wheels at the same time, then the stress on the axle is the same at and everywhere between the two frame rail support points. So the axle can bend anywhere or everywhere along that length. Outward from the supports the bending stress drops off, so bending at the very ends of the tube is unlikely. 

Case 2) If you hit a bump with one wheel only, the stress on the tube is max at the support nearest that wheel and tapers off both outbound and inbound from that point, so you are most likely to bend the axle right at the support.

Case 2 is probably more likely than 1 but both appear to be pretty common. 

One thing to point out is that the tube is really stiff and so does not deflect much at all before it yields under load. The point of yield is considered a bending failure because after that it won't spring back to its original shape. The points of maximum deflection are the ends and at the center, but it only deflects about a couple of tenths of an inch or so at either location before it fails. So its going to be hard to see the bend especially outward from the supports. Its easier to see if it has occurred inboard because you can run a string line and measure up in the center. At the ends its easier to see the bend as negative camber than it is to see it in the axle itself. 

Yes, you can push the axle up in the center to try to remove some camber, but that won't bend the axle ends back where they were it they were bent. Better (my opinion) to take it to an axle shop which has the proper equipment  to do it correctly. 

It doesn't help to only support the axle tube in the center. I think one thing that's maybe confusing folks is that the points of maximum deflection are not the points of maximum stress in this case. In a cantilever the points of maximum stress (the support points) are actually the points of zero deflection. The center is also one of the points of max stress in case 1, but all the other points between the two supports get loaded the same so supporting the center is only going to move the bending failure somewhere else. In case 2 the stress at the center of the axle is pretty low. 

It does help to reinforce the axle tube along its entire length of course, which is what "my" u bolted angle does. If I didn't support it continuously I would be creating a weak point at the center which would then become the point of failure in case 1.  

It does help to add support to the tube ends like both marwayne's and toyanvil's designs do. In those designs the supports can apply torque to the rpod frame rails, which potentially creates other problems. Marwayne and toyanvil have considered and dealt with that issue in different ways. 
 




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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: offgrid
Date Posted: 12 May 2019 at 9:19am
Originally posted by StephenH

 

I looked at those and saw that there were less expensive ones that did not have a housing. I don't know if any of them are made to withstand the conditions under the R-Pod as it is going down the road, especially if it is raining. If that is the case, this one would likely work since it is also Bluetooth and you could put it in a waterproof container strapped to the axle with a battery to power it. If you had a laptop with Bluetooth or a Bluetooth dongle, that would work.
https://www.amazon.com/Accelerometer-Triple-Axis-Acceleration-Transducer-BWT61/dp/B018NL1R0Y/ - https://www.amazon.com/Accelerometer-Triple-Axis-Acceleration-Transducer-BWT61/dp/B018NL1R0Y/



In thinking about this some more I realized that the accelerometer does not need to be attached to the axle. The axle and frame are rigidly bolted together so it should be fine to attach the accelerometer to the trailer itself. That opens up using one of the cheap or free smartphone g force apps. We'd need to get one that records max events, and stick or strap the phone to the rpod floor directly above one of the axle to frame attachment points, or as close to there as possible.  That should do it. 
 




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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: bhesse
Date Posted: 01 Aug 2019 at 10:19pm
Do you have a parts list and lengths needed I would like to add this

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2015 RP-178


Posted By: StephenH
Date Posted: 01 Aug 2019 at 11:20pm
My mods detail what I did. http://www.rpod-owners.com/forum_posts.asp?TID=7712&PID=124418&title=our-escapod-mods#124418 - This is a direct link to my axle mod .


-------------
StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS



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