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Old 07-12-2016, 06:57 PM   #1
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Are axle down angles correct?

My 32 degree Axis/Dexter axles, which are listed as "32D" on the sticker, appear to be more like 26 degrees. I was looking forward to the extra boost in height, which is why I got the 32s. Unfortunately I haven't been able to reach Colin, and I'm also waiting to hear back from Axis. I am curious about others thoughts as well though. In the event I am measuring the angle correctly, how much increase in trailer height am I missing with this 6 degree loss?

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Old 07-12-2016, 09:56 PM   #2
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You'd be losing about 1/2".

I think the round hub at the axle tube is slightly different diameter than the round hub for the wheel bearing which will give a different angle than from the center axis of the arm.

I wouldn't trust the phone app to be all that accurate. They really can only give a pretty good idea, not a engineered accurate measurement.
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Old 07-14-2016, 06:35 PM   #3
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Are axle down angles correct?

Thanks, HiJoe. I suspect you're probably right.

I haven't had much luck with Dexter/Hensley. I sent the images above and was put in touch with someone from their QA department. The initial feedback I got was that the weight of the hubs and drums could be causing the 6 degree difference since the axles are upside down in the pics. Obviously ridiculous since if that's the case I'd be in serious trouble when the axles are under the load of the trailer. Aside from that issue, while comical and somewhat disturbing at the same time, they were extremely helpful and are looking into the issue further. They also reassured me that they would replace the axles if they turn out to be the wrong down angle. I suspect though that HiJoe is correct.
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Old 07-14-2016, 06:43 PM   #4
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Are axle down angles correct?

Also, I'm not sure if this chart is applicable, but the #11 at 32 degrees under no load measurement appears to match up. I found this on Dexter's site.

http://dexteraxle.com/i/u/6149609/f/...stallation.pdf

The measurements for the #11 in this doc appear to match up as well.

http://dexteraxle.com/i/u/6149609/f/...nformation.pdf

While I believe our axles are custom made and may have their own set of specs, I thought I'd include these in case any of the information is helpful to others.
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Old 07-14-2016, 07:04 PM   #5
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Quote:
Originally Posted by KYAirstream View Post
My 32 degree Axis/Dexter axles, which are listed as "32D" on the sticker, appear to be more like 26 degrees. I was looking forward to the extra boost in height, which is why I got the 32s. Unfortunately I haven't been able to reach Colin, and I'm also waiting to hear back from Axis. I am curious about others thoughts as well though. In the event I am measuring the angle correctly, how much increase in trailer height am I missing with this 6 degree loss?

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I don't know what, if any, difference it will make, but how is "down angle" supposed to be measured? Don't you have the axles upside-down? The weight of the hubs, etc reduces the angle when measured upside down.

Al
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Old 07-14-2016, 07:31 PM   #6
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Are axle down angles correct?

How is down able suppose to be measured? That's precisely my question and surprisingly one I haven't been able to get an answer to from Dexter. The individual I spoke with at Dexter, however, didn't dispute my method of measurement. Although as HiJoe suggested, I question my methods accuracy.

As far as your remark about them being upside down, I don't so how the weight of the hubs and drums would change the angle significantly. If that were the case, then just imagine what would happen once the full weight of the trailer is bearing on them.
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Old 07-14-2016, 08:28 PM   #7
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Originally Posted by KYAirstream View Post
As far as your remark about them being upside down, I don't so how the weight of the hubs and drums would change the angle significantly. If that were the case, then just imagine what would happen once the full weight of the trailer is bearing on them.
You are right, of course about the weight of the drums and hubs.

Al
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Old 07-14-2016, 08:51 PM   #8
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Originally Posted by KYAirstream View Post
Also, I'm not sure if this chart is applicable, but the #11 at 32 degrees under no load measurement appears to match up. I found this on Dexter's site.

http://dexteraxle.com/i/u/6149609/f/...stallation.pdf

The measurements for the #11 in this doc appear to match up as well.

http://dexteraxle.com/i/u/6149609/f/...nformation.pdf

While I believe our axles are custom made and may have their own set of specs, I thought I'd include these in case any of the information is helpful to others.
In just about every picture/ drawing in the PDFs the hub diameter at the axle tube is larger than the hub diameter at the wheel spindle. Not sure why they would draw them this way if it wasn't representative of reality. So measuring from the top of one to the top of the other, as you are, introduced a angle different than that that that would be measured from the center of each hub along the center axis of the arm. A radius difference of .3 inches would cause the 6 degree difference.
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Old 07-14-2016, 08:56 PM   #9
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Are axle down angles correct?

Yes, I noticed that as well. It's difficult to measure because of the welds, but the difference between the hubs does appear to be about what you calculated.

I'm curious how you calculated a 6 degree outcome from .3 though? Based on .017 per degree per inch, for 6 degrees and an arm length of 6 inches, would be .6 inches.
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Old 07-15-2016, 12:49 PM   #10
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Down Angle

Have you considered flipping the axle right side up and measure from the fulcrum point along the arm and then along a horizontal line. Use trigonometry to calculate. My guess is that you may be measuring something that more accurately than intended.

I went with the standard down angle on my 76 Overlander recently, when I installed the axles I chose not to deepen the slot for the increased axle dimension, I only widened the slot. That bought me almost 3/8" in increased height. See photo attached pdf.

My new axles picked the bumper up almost 5". I used to drag the rear bumper on every curb, no longer.

I can even almost raise the ball up one notch on my hitch.

Good luck

Kristien
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Old 07-15-2016, 03:54 PM   #11
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Yes, I noticed that as well. It's difficult to measure because of the welds, but the difference between the hubs does appear to be about what you calculated.

I'm curious how you calculated a 6 degree outcome from .3 though? Based on .017 per degree per inch, for 6 degrees and an arm length of 6 inches, would be .6 inches.
The .6" is what you would get for the difference in diameter of the circles with 6 degree slope for a 6" straight line from tangent to tangent. If you put the circles centered on an axis then the difference would be .3" radius, so you'd see (or not) that if you were having to look from one side. If they're still off you should be able to get an idea measuring close to center of each hub. They are cast so the edges attend exactly easy to measure as you mentioned. Calipers would give a good measure but not many people including myself keep them around. 2 carpenters squares slid opposite each other can form a rudimentary caliper.
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Old 07-15-2016, 08:08 PM   #12
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Are axle down angles correct?

Seabloom - that's a great idea, and I imagine that would provide a more accurate angle. As far as the notch, I was under the impression that the top should be enlarged slightly so the trailer frame is resting on the axle bracket. Probably not a big deal to have the axle mounting plate bearing on the axle tube though.
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Old 07-15-2016, 08:11 PM   #13
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HiJoe- I think your spot on and when taking that difference into account, I believe the axles are probably pretty close to 32 degrees. Thanks for helping me sort that out. You were far more helpful than Dexter was.
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Old 07-15-2016, 08:34 PM   #14
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Originally Posted by KYAirstream View Post
Sealbloom - that's a great idea, and I imagine that would provide s more accurate angle. As far as the notch, I was under the impression that the top should be enlarged slightly so the trailer frame is resting on the axle mounting bracket. Probably not a big deal to have the axle mounting plate bearing on the axle tube though.
Trailer frame doesn't need to rest on the top of the mounting bracket. You may have to notch larger front and back if the new tube is larger than the old ones. The 5/8" grade 8 bolts you use to mount them have a sheer strength of 27920lbs each. So more than enough support. Less notching=less work=more happy.
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Old 07-15-2016, 09:27 PM   #15
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Are axle down angles correct?

Both my axles are in and notching with a pneumatic cut off wheel made the job easy. I did a 2" vertical depth for all notches. This required no more than 1/4" taken from the top of the notch for the mounting brackets to bear against the frame, and some mounting plate notches didn't require hardly any removal from the top. Each notch was widened to accommodate the larger axle tubes.
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