Tire rubbing fender . Looking for advice - R-pod Owners Forum

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GlueGuy

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Joined: 15 May 2017
Location: N. California
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Topic: Tire rubbing fender . Looking for advice
Posted: 25 Apr 2019 at 5:12pm

Corrected link offgrid meant to send: https://mechanicalelements.com/trailer-axle-springs-torsion-axle/

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

offgrid

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Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 25 Apr 2019 at 4:42pm

Actually, everything else being equal, it looks like the frame load is worse with the torsion axle, because it applies both a force and a moment to the frame due to the torque produced by the torision arm. The spring axle only applies a force.

Here is an interesting article on the pros and cons of the two axle types:

https://echanicalelements.com/trailer-axle-springs-torsion-axle/

I suspect that keeping the ride height lower is probably the main reason FR uses torsion axles on the rPods. If you're going to lift the trailer anyway with a lift kit a spring axle might work ok.

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

podwerkz

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Joined: 11 Mar 2019
Location: Texas
Online Status: Offline
Posts: 966

Posted: 25 Apr 2019 at 10:34am

As a general question, I wonder if it might be practical to beef-up the frame and have leaf-spring mounts welded on and install a regular trailer axle...I suspect the ride would be a bit rougher.

But it would last almost forever, and the spring pack can be tailored (even side-to-side) for the weight being carried.

r･pod 171 gone but not forgotten!

offgrid

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Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 25 Apr 2019 at 7:01am

When supporting the frame the main thing is to spread out the load, the rPod frame rails are only 0.1 inch thick IIRC. Some 2x4's would probably do it. Lift behind the axle so you don't end up with the trailer coming up off the tougue jack.

I don't think an axle shop can help get a low cost fix in this case. You are not seeing the more common bent axle problem others have reported. That would show up as negative camber at the wheels and/or an axle tube that has lost its crown, neither of which you have.

In this case there are a couple of other possibilities besides damaged rubber cords. One is that it is possible that the axle tube has been twisted, although as I said I think that unlikely because tubes are very strong in resisting torsional stress. If you want to exclude that possibility comparing the angles of a couple of straight edges clamped to the flats at each end of the axle would probably work.

The other possibility is that the torsion rod inserted into the cords has twisted, in which case the fix is the same as for the cords themselves: new axle. If it were me and I was stuck putting a new axle under the trailer I wouldn't want to put back the same marginal part that couldn't handle the load in the first place, I'd go for a heavier axle. But that's me.

An inexpensive fix which you might find acceptable would be add about a 1/2 to 1 inch axle riser on the slide side. 1 inch height difference is pretty high but 1/2 inch is not at all unusual, my 179 is about 3/8 IIRC. After all, the trailer slide side is heavier so it will ineveitably site lower.

Good luck with the dealer and FR, please let us know what you end up doing.

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

GlueGuy

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Joined: 15 May 2017
Location: N. California
Online Status: Offline
Posts: 2630

Posted: 24 Apr 2019 at 8:48pm

Replacing the axle is not too big a deal if you are handy. There are only a few bolts to remove plus the brake wires. The biggest challenge is supporting the frame so you can remove the old one and install the new one.

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

tent2pod

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Joined: 13 Mar 2019
Location: Western pa
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Posts: 9

Posted: 24 Apr 2019 at 8:03pm

After making the checks that I did and reading all of your input the rubber cords being the problem makes a lot of sense to me . The two torsion arms are not at the same angle with no load on them .

I did a lot of research on the r pods and was aware of the axles bending and I made sure there was no visual tilt to ether wheel or uneven tire wear signs before purchasing this one . I didn't read of the rubber cords being much of a problem .

We have an appointment to have it looked at by the dealer that we bought it from next week . We are still super excited and can't wait to get out in it . It's just going to be a little later than we hoped but that is ok .

Has anyone purchased and installed the axle them self .

Toyanvil

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Joined: 15 Feb 2019
Location: Bakersfield
Online Status: Offline
Posts: 157

Posted: 24 Apr 2019 at 7:06pm

Are you saying your trailer is not level to the ground? of so, I would look for a frame repair shop in your town that works on trailers and have your trailer axle aligned, should be a round $200. and enjoy your trailer, that is what I did.
The real problem with the RPOD is the frame rails are to narrow for the axle and there is to much leverage. The frame rail to hub face is will over the 9 inch max recommended, mine is close to 14".
If your trailer wheels are not straight up or real close to it or are wearing tires odd, you should have it checked at a good frame shop.

Happy Tripping View Drop Down

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Joined: 27 May 2014
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Posts: 473

Posted: 24 Apr 2019 at 5:19pm

I am very sorry to hear of your problem.

The 3500# axles are apparently 'industry standard', whatever that means, for trailers of the r-pod's weight. Our 171's axle got bent, somewhere. I've chosen to go thru tires at a 2x rate rather than spend the $$ to get a new axle. I have no idea whether or not that is a feasible option for you. If not, replacing the axle with a 3500# axle is probably your best option in terms of the cost/benefit ratio but there is no guarantee the axle won't get bent over time like ours did. Still, the odds are on your side, there are a lot of smaller trailers out there with 3500# axles that DON"T get bent.

Whatever, don't let this turn you off trailering, once you get past this admittedly nasty incident, get out there and I'm sure you will enjoy your trailer.

offgrid

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Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 24 Apr 2019 at 4:34pm

The 3/16 crown sound good.

If you measured the torque arm angles with no load on them then they should be the same. If the slide site is rotated significantly further upwards then I agree with GlueGuy, it sounds like probably the rubber cords which carry the axle torsion load have been over-compressed. I doubt that the axle tube itself could be twisted without a lot more load on it.

There is no way to fix that short of axle replacement as the cords are installed compressed and frozen using liquid nitrogen at the factory and allowed to thaw. While FR should take care of it they are saying that a 1 inch height difference is OK, which is pretty unreasonable I think. So I doubt they will take care of it under warranty, but you can try by arguing that as is the trailer isn't useable because its rubbing. If that is unsuccessful then unfortunately you'll likely have to buy a new axle if you want to get rid of the 1 inch height difference. Adding a lift kit is fine but doesn't fix your underlying problem.

If you have to pay for it yourself you might consider getting the next heavier load rated axle which would be 5200 lbs vs. 3500, but if you did you'd need different brake assemblies and 6 lug wheels as well as the axle itself. More $$. Lippert makes these axles so if you want to go that route you could contract them directly, FR and the dealer will I'm sure tell you you have to buy the same axle that's on there now. The 3500 lb axle is a bit weak for the application, if its any consolation you are not the first person to have had problems with them.

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

GlueGuy

Senior Member

Joined: 15 May 2017
Location: N. California
Online Status: Offline
Posts: 2630

Posted: 24 Apr 2019 at 12:34pm

You might have hit a rough bump or something, plus the slide-out side is a bit heavier. The clocking is fixed at the factory, so the only thing I can think of is a manufacturing defect, or the previously mentioned elastic tubes inside the axle tube.

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

Author	Message Share Topic Printable Version Google Delicious Digg StumbleUpon Windows Live Yahoo Bookmarks reddit Facebook MySpace Newsvine Furl Topic Search Topic Options Post Reply Create New Topic
GlueGuy Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2630	Topic: Tire rubbing fender . Looking for advice Posted: 25 Apr 2019 at 5:12pm
	Corrected link offgrid meant to send: https://mechanicalelements.com/trailer-axle-springs-torsion-axle/
	bp 2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 25 Apr 2019 at 4:42pm
	Actually, everything else being equal, it looks like the frame load is worse with the torsion axle, because it applies both a force and a moment to the frame due to the torque produced by the torision arm. The spring axle only applies a force. Here is an interesting article on the pros and cons of the two axle types: https://echanicalelements.com/trailer-axle-springs-torsion-axle/ I suspect that keeping the ride height lower is probably the main reason FR uses torsion axles on the rPods. If you're going to lift the trailer anyway with a lift kit a spring axle might work ok.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

podwerkz Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966	Posted: 25 Apr 2019 at 10:34am
	As a general question, I wonder if it might be practical to beef-up the frame and have leaf-spring mounts welded on and install a regular trailer axle...I suspect the ride would be a bit rougher. But it would last almost forever, and the spring pack can be tailored (even side-to-side) for the weight being carried.
	r･pod 171 gone but not forgotten!

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 25 Apr 2019 at 7:01am
	When supporting the frame the main thing is to spread out the load, the rPod frame rails are only 0.1 inch thick IIRC. Some 2x4's would probably do it. Lift behind the axle so you don't end up with the trailer coming up off the tougue jack. I don't think an axle shop can help get a low cost fix in this case. You are not seeing the more common bent axle problem others have reported. That would show up as negative camber at the wheels and/or an axle tube that has lost its crown, neither of which you have. In this case there are a couple of other possibilities besides damaged rubber cords. One is that it is possible that the axle tube has been twisted, although as I said I think that unlikely because tubes are very strong in resisting torsional stress. If you want to exclude that possibility comparing the angles of a couple of straight edges clamped to the flats at each end of the axle would probably work. The other possibility is that the torsion rod inserted into the cords has twisted, in which case the fix is the same as for the cords themselves: new axle. If it were me and I was stuck putting a new axle under the trailer I wouldn't want to put back the same marginal part that couldn't handle the load in the first place, I'd go for a heavier axle. But that's me. An inexpensive fix which you might find acceptable would be add about a 1/2 to 1 inch axle riser on the slide side. 1 inch height difference is pretty high but 1/2 inch is not at all unusual, my 179 is about 3/8 IIRC. After all, the trailer slide side is heavier so it will ineveitably site lower. Good luck with the dealer and FR, please let us know what you end up doing.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

GlueGuy Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2630	Posted: 24 Apr 2019 at 8:48pm
	Replacing the axle is not too big a deal if you are handy. There are only a few bolts to remove plus the brake wires. The biggest challenge is supporting the frame so you can remove the old one and install the new one.
	bp 2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost

tent2pod Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13 Mar 2019 Location: Western pa Online Status: Offline Posts: 9	Posted: 24 Apr 2019 at 8:03pm
	After making the checks that I did and reading all of your input the rubber cords being the problem makes a lot of sense to me . The two torsion arms are not at the same angle with no load on them . I did a lot of research on the r pods and was aware of the axles bending and I made sure there was no visual tilt to ether wheel or uneven tire wear signs before purchasing this one . I didn't read of the rubber cords being much of a problem . We have an appointment to have it looked at by the dealer that we bought it from next week . We are still super excited and can't wait to get out in it . It's just going to be a little later than we hoped but that is ok . Has anyone purchased and installed the axle them self .

Toyanvil Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 Feb 2019 Location: Bakersfield Online Status: Offline Posts: 157	Posted: 24 Apr 2019 at 7:06pm
	Are you saying your trailer is not level to the ground? of so, I would look for a frame repair shop in your town that works on trailers and have your trailer axle aligned, should be a round $200. and enjoy your trailer, that is what I did. The real problem with the RPOD is the frame rails are to narrow for the axle and there is to much leverage. The frame rail to hub face is will over the 9 inch max recommended, mine is close to 14". If your trailer wheels are not straight up or real close to it or are wearing tires odd, you should have it checked at a good frame shop.

Happy Tripping Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 27 May 2014 Online Status: Offline Posts: 473	Posted: 24 Apr 2019 at 5:19pm
	I am very sorry to hear of your problem. The 3500# axles are apparently 'industry standard', whatever that means, for trailers of the r-pod's weight. Our 171's axle got bent, somewhere. I've chosen to go thru tires at a 2x rate rather than spend the $$ to get a new axle. I have no idea whether or not that is a feasible option for you. If not, replacing the axle with a 3500# axle is probably your best option in terms of the cost/benefit ratio but there is no guarantee the axle won't get bent over time like ours did. Still, the odds are on your side, there are a lot of smaller trailers out there with 3500# axles that DON"T get bent. Whatever, don't let this turn you off trailering, once you get past this admittedly nasty incident, get out there and I'm sure you will enjoy your trailer.

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 24 Apr 2019 at 4:34pm
	The 3/16 crown sound good. If you measured the torque arm angles with no load on them then they should be the same. If the slide site is rotated significantly further upwards then I agree with GlueGuy, it sounds like probably the rubber cords which carry the axle torsion load have been over-compressed. I doubt that the axle tube itself could be twisted without a lot more load on it. There is no way to fix that short of axle replacement as the cords are installed compressed and frozen using liquid nitrogen at the factory and allowed to thaw. While FR should take care of it they are saying that a 1 inch height difference is OK, which is pretty unreasonable I think. So I doubt they will take care of it under warranty, but you can try by arguing that as is the trailer isn't useable because its rubbing. If that is unsuccessful then unfortunately you'll likely have to buy a new axle if you want to get rid of the 1 inch height difference. Adding a lift kit is fine but doesn't fix your underlying problem. If you have to pay for it yourself you might consider getting the next heavier load rated axle which would be 5200 lbs vs. 3500, but if you did you'd need different brake assemblies and 6 lug wheels as well as the axle itself. More $$. Lippert makes these axles so if you want to go that route you could contract them directly, FR and the dealer will I'm sure tell you you have to buy the same axle that's on there now. The 3500 lb axle is a bit weak for the application, if its any consolation you are not the first person to have had problems with them.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

GlueGuy Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2630	Posted: 24 Apr 2019 at 12:34pm
	You might have hit a rough bump or something, plus the slide-out side is a bit heavier. The clocking is fixed at the factory, so the only thing I can think of is a manufacturing defect, or the previously mentioned elastic tubes inside the axle tube.
	bp 2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost