With a dry weight of 2960 lbs, and a maximum weight of 3500, there's just not enough carrying capacity.
This is an axle upgrade to support a maximum weight of 5200 lbs.
Dexstar conventional (017-118-xx) wheels, 15x6JJ rim, 6x5.5" bolt circle, 2600 lb. rating. Those and the conical baby moons from etrailer.
15x1.8" Atlas Port-o-walls from Mooneyes. These didn't work out - they tore apart during the first long trip.
VTR TR-416 valve stems. "IH Red" Majic Tractor paint from Tractor Supply.
Flexiride 5200 lb axle with self-adjusting electric brakes, from Southwest Wheel.
Flexiride axles are unique because they allow adjustment of the trailing arm angle, unlike the original Lippert ones. You can also replace the arm/stub seperately, so a major bearing failure doesn't mean you have to buy a whole new axle.
The new axle weighs ~300 lbs. Much easier (read: lighter) to deal with if the trailing arms/brakes are removed from both ends. It comes as bare metal. I sprayed cold galvanizing (zinc rich) paint on it, finish paint is an important future direction.
Axle dimensions as specified.
Old axle out. It's bolted (side mount) to an angle iron which is welded to a 2x2 spacer which is in turn welded to the frame. Riverside will sell you a "lift kit" to raise the camper about 3 inches, but the interesting thing is that the original trailing arm angle is up, which isn't good for anything. If they had simply spec'd the axle properly, it would have more compliance (softer ride) and also raise the camper an inch or two. I can only guess they prioritized the overall height above all else.
Note that the camper was supported in 10 places - 4 jack stands, the 4 stabilizers, the tongue jack and a jack under the rear bumper. So, not one of them was responsible for more than about 400 lbs, and any one could have failed without issue. It was very stable.
I used a cutoff wheel to remove the part of the original angle iron which the old axle was bolted to and which was hanging down in the way.
New axle is in. The dimensions (measure 10 times, cut once) worked out great. It bolted directly to the 2" spacer. I was able to reuse the original 5/8" hardware. One bolt was about 5" into the 2x2 spacer which doesn't provide much room, so you need a way to keep the bolt head in place while torquing the nut. A 15/16" box wrench would work best. I didn't have one handy, but was able to wedge a chisel between the wall and a bolt flat and torque it down.
Afterward, reinstall the trailing arms/brakes (I ended up setting them at 6° down angle). It clamps with a 5/8x14 grade 8 fine thread bolt, so 180 ft-lbs - you need hefty tools. The final result was about a 4" lift, so the frame is now ~18" off the ground.
With the increased height, it's a big step up with the original step. So, a double step fixed that. Stromberg Carlson SM-24-20 (same as Lippert 341500). The mounting is about 5/8" narrower, so I used a couple of longer bolts and some washers as spacers on the door hinge side.
The mounting, as it worked for me. The axle bracket lined up within 1/8" of the rear end of the 2x2 spacer. But measure for yourself, I can't promise Lippert (the original axle/frame manufacturer) is consistent. Other than lifting the new axle into position, the hardest part of the change was drilling the holes to mount the new axle. I used a 23/32" drill, which give a little bit of slop for fitting the 5/8" hardware. As long as the hole is centered in the 2x2 riser, the original washers will fit just fine.
...and how the mounts matched up with the frame (the one I received was about 1/8" wider than spec). The frame is 2.0" wide, and the axle mounting brackets are 2.5".
View of mounting.
Legal stuff.
I did quite a bit of research, and believe the 2x4" box section frame rails on the 177 are sufficient to support the increased weight rating for the camper, once the upgraded axle is added. You'll have to decide for yourself whether that is the case. I'm not responsible for what you choose to do.
To be legal with the upgrade, you need to add info to the spec label on the camper. I'm not a lawyer, I'm not your lawyer, and this isn't legal advice. This is covered in 49 CFR 567.4 and 49 CFR 567.7. In essence:
(1) The statement: ‘‘This vehicle was
altered by (individual or corporate
name) in (month and year in which alterations
were completed) and as altered
it conforms to all applicable Federal
Motor Vehicle Safety, Bumper and
Theft Prevention Standards affected by
the alteration and in effect in (month,
year).’’ The second date shall be no earlier
than the date of manufacture of
the certified vehicle (as specified on
the certification label), and no later
than the date alterations were completed.
(2) If the gross vehicle weight rating
or any of the gross axle weight ratings
of the vehicle as altered are different
from those shown on the original certification
label, the modified values
shall be provided in the form specified
in § 567.4(g)(3) and (4).
567.4(g)(3) and (4):
(3) ‘‘Gross Vehicle Weight Rating’’ or ‘‘GVWR’’ followed by the appropriate
value in pounds[...]
(4) ‘‘Gross Axle Weight Rating’’ or
‘‘GAWR,’’ followed by the appropriate
value in pounds, for each axle[...]
You also need to block off the original tire info from the VIN label, update the door label, and update the tire capacity placard, per 571.110 S4.3.2:
a new placard or placard and label shall be affixed, so as to obscure the original placard, to an altered vehicle
...and this is what the updated labels look like. The original door label for the 177 was incorrect, it was based on a 20 gallon fresh water tank when in reality they have a 39 gallon one. It's corrected here. A version in ODG format can be downloaded here. This has been formatted to print on common 2x4" labels - like the Avery 15513 weatherproof ones. The numbers were based off the original numbers (cargo weight 520), +1580 lbs for the upgrade (it's a 5200 lb axle, but 225/75-15 load range D tires only handle 5080 lbs), then -100 lbs for the additional weight of the new axle. So, 520+1580-100=2000.
