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SilverHoot · 08-20-2009, 10:48 AM

I'm going to be purchasing two new axle assemblies for my 1967 Tradewind very soon. Everything I know and everything I am confused about I learned here on the forum. What is the 'down angle' that should be specified? I have read anywhere from 20.5 to 45 degrees. I think I read that Airstream was originally 22.5 degrees but then I read that it would be better to have them at 32 to 35 degrees to accommodate the higher ride height of today's vehicles. Will all the angles ride the same the only difference being the height of the trailer? Does the axle rating change in relation to angle?

87MH · 08-20-2009, 10:59 AM

The axles will "ride" better when they are at "0" degrees loaded, this allows for the maximum vertical displacement for a given shock (bump) impact. The Dexter chart (below) suggests an "impact bump" "up" displacement of 3" - I do not know if your trailer has enough clearance for that.

I went with a 45 degree angle when I replaced my axles a couple of years ago - anywhere from 20 to 45 as a start angle should work.

A 22.5 degree down start angle is very popular with Airstream rebuilders here on the Forums. I went with the higher start angle to give me a bit more clearance between the bumper and the asphalt on the rear of the Sovereign. Seems I was always draggin' the Ash of the trailer when the original (worn out) axles were riding at "0" degrees - yuk yuk

.

See below for the various offsets available from Dexter - I am extremely happy with the Dexter #11's (appropriately derated) as replacements on the '78 Sovereign.

Axle rating (or derating) remains the same regardless of the start angle.

When "derating" an axle the manufacturer will only insert a portion of the original length of the elastomeric elements used as a "spring" in the axles. This allows for (in the case of the Dexter #11's below) a variable load rating of 4,000lbs to 6,000lbs in the same axle body. The factory will further "derate" (shorten the elastomeric element) in my case, to 3,600lbs per axle. The benefit of this is that the purchaser gets a MUCH heavier axle tube and arm assembly (as compared to some of the competition) and heavier spindles and bearings as copared to a lighter rated axle, and at the same time enjoys the benefit of the "softer" ride (since the "rubber" element is shortened) such as found on a #10 axle.

The complete current Dexter catalogue is here:
http://dexteraxle.com/i/u/1080235/f/...te_Catalog.pdf

87MH · 08-20-2009, 11:37 AM

I cut one of the old axles apart after I changed it out.

Below is what 30 year old elastomers look like after supporting the full weight of a Sovereign for 30 years.

The arms of the axle were at about "0" degrees when I changed them out - and they stayed close to the same angle when I took them off. As a comparison, the new Dexters axles allow for the tires to be raised and lowered almost 3 inches when jacking the trailer to relieve load during storage and non-use intervals.

Aerowood · 08-20-2009, 11:37 AM

As an added note, with the Dexter #11 you will also get 12" brakes. I did 22.5 degrees down but I did not have Arse dragging issues with my 21'. I also went with the 1" offset as was the original. You can get the axle with as much as 3" offset on the mounting plate. My new dexter lifted me around 4".

SilverHoot · 08-20-2009, 12:03 PM

Thanks, I'm deciding between AXIS and DEXTER. I was asked what profile my current axles are and am not sure what is meant by profile is this the same as offset? What is offset? Sorry for all the questions.

87MH · 08-20-2009, 01:03 PM

Quote:

Originally Posted by SilverHoot

... I was asked what profile my current axles are and am not sure what is meant by profile....

Profile COULD BE a bunch of things describing the dimensions of the entire axle...probably (maybe) the questioner was referring to the height of the bracket mount on the tube to trailer frame hookup. When I was ordering my axles I was only aware of two heights in the profile bracket available - the "high profile" and the "low profile". In my case, the "high profile" was just right, with the top of the mounting bracket flange just nesting onto the bottom of the upper trailer axle frame flange.

Many thanks to "PizzaChop" here on the forums for supplying me with this order form and the measurements he used. Members should give him thanks and praise if they find it useful.

The measurements for my '78 Sovereign were almost identical. I did not order the side mount bracket - the high profile mount was just right. The mounting holes Dexter uses are about 1/2 of a bolt diameter off horizontaly - you will have to drill either the trailer frame or the axle bracket on one hole on either side. I found the trailer frame to be easier to access and drill in my case.

I understand that Dexter will now install a shock bracket if ordered initially - they did not offer this as an option to me - if you do not have access to a welder it would very advantageous to have the factory install the shock mount

If ordering, it's best to thoroughly familiarize yourself with the various names of the components in the axle descriptions contained in the Dexter catalogue I referenced in an earlier post.

Quote:

Originally Posted by SilverHoot

... What is offset? Sorry for all the questions.

What I meant by "Offset" was the various amounts of vertical tire travel (articulation and full load dimensions) allowed by the various starting angles as referenced in the Dexter #11 dimension sheet, also in the same earlier post.

Make sure all of the dimensions are correct before you order or let a trailer axle manufacturer rep measure and order it for you.

Most trailer repair/axle shops swap axles day in and day out - the main problems with letting such a shop handle an Airstream are the hidden frame supports and the relatively weak frame as compared to transport trailers. Significant damage will occur by attempting to jack up an Airstream at the wrong points.

Minno · 08-20-2009, 02:23 PM

I thought Inland Andy always recommended a 35 degree down angle? Especially if towing behind a big SUV or PU Truck. Am I miss-remembering?

Chris

LHall · 08-20-2009, 02:32 PM

You are remembering correctly. We replaced our axles and at the suggestion of Inland we used the 35 degree angle. We have been extremely happy with the new axles and the added clearance. There are some definite advantages such as being able to lay on your back under the trailer without having the bellypan right in your face. It is a breeze to remove a wheel if needed, before it was difficult to manuever it out from the wheel well. We are able to slide our grey tote or a 5 gal bucket under the dump valve with no issues at all. Recently we camped in a remote area on pretty rough road with large rocks and gravel we had no issues at all. Changing our axles raised our trailer up nearly 4 inches.

Whichever brand you choose, I would definitely recommend the higher angle.

SilverHoot · 08-20-2009, 03:38 PM

Yes, I think we all got that angle from the same source. Now to find out if it available from either Dexter or Axis. LHall, funny that you brought up wheel removal, I was worried I was going to damage the wheelwell removing one of my wheels. I attributed to the axles being completely shot and them not dropping at all when jacked up. It was such a job that I think I will drop the axles with them attached(might be easier anyhow).

SilverHoot · 08-20-2009, 03:41 PM

87MH,Great picture and axle order from PizzaChop, thank-you.

Aerowood · 08-20-2009, 04:11 PM

The brake drum assembly on the Dexters set further inboard on the hub then on the Henshens, this makes more room for the tire/wheel assemble to slide into the wheelwell. A big plus on changing tires.

nmbosa · 08-20-2009, 04:59 PM

Quote:

Originally Posted by Aerowood

The brake drum assembly on the Dexters set further inboard on the hub then on the Henshens, this makes more room for the tire/wheel assemble to slide into the wheelwell. A big plus on changing tires.

Aerowood, does that make it any more difficult to install and/or replace shocks? On my current set-up (original leaf springs) there is very little space between the shock mounts and the tires. So little room, that I was wondering if I could order my axles a 1/2 inch to an inch wider to allow for better clearance since I seem to have more than enough clearance to the outside of the wheel wells.

Aerowood · 08-20-2009, 05:19 PM

I wouldn't know the answer on a leaf axle. I welded the shock mounts on myself on the Torqueflex so I was able to check. The shock mounts a little differently now then the original and much easier to change now. If it's any consolation I ordered my hubface to hubface dimension 5/8" wider (or 5/16" per side) then the stock axle by accident. I didn't find out until I removed the old to install the new and I had them setting side by side. It was not a factor and my tire/wheel assembly slide into the well with plenty of room to spare. This was on my 71, and I imagine there are differences between our wheel wells, and the location of the shock mounts.

Mikethefixit · 08-20-2009, 06:21 PM

I also went with 35 degree down start and 3500 lbs rating. Although I went with Henshen, and axle is an axle. I did gain about 4 to 5 inches in trailer height. What with the Airstream low profile anyway I cant tell the difference. I did see a change in the tongue height however. I was using a 4 in BLUE OX drop in the reciever to make the trailer level on the 1 ton. But after changing axles I was able to discontinue use of the 4 inch drop and the comb is now level.

eubank · 08-20-2009, 06:41 PM

We also gained quite a bit of height on the 67 when we installed the Henschens earlier this summer. Had to redo the hitch on the truck as a result. And find the footstool in order to be able to climb into the rig.

Lynn