DIY T@B 400 axle upgrade

atlasb

Reason: To upgrade from 3500 lb axle to the newer 3900 lb in the non BDL 400.  Axle ordered through Missouri Teardrops, Dana Parsons.  Installed by : an "Old Guy in His shop"

Research proceedure:  Not much info available, so looks Like it is seat of the pants type operation.

Implement project: Brain storm (late at night when supposed to sleep),  gather tools and parts.

Proceed:  Locate T@B 400 in home shop, level solid surface, Loosen all wheel lug nuts, but do not remove.  Also looden all 4 axle mounting bolts per side but do not remove. Raise tongue as far as it will go,  use floor jacks (2 ea) to raise T@B high enogh to place temporary blocks under weels for support. Place Jack stands ( 6 ea) under frame behind axle, in front of axle and near front of frame. Un fasten fasteners holding plastic belly pan and roll under trailer to clear path for axle to be removed.  Place new axle on 2 furniture dollies to enable moving in and out of position.  When belly pan is clear,  raise rv enough to remove blocks supporting wheel/ tires and remove the wheel/ tires.  Place under the frame the wheel/ tire to support if something happens. Remove the heat shrink material from the 2 wires per side brake connections and cut the wires leaving the connections with the rv. Take 2x8 inch pre cut board under axle spaning the width of the axle mounting brackets on the furniture dolly and position under the installed axle.  Use floor jack from beneath the rear of the rv and place under the center of the 2x8 and raise into position supporting the axle.  Remove all 8 (4 per side) axle mounting bolts and carefully lower the axle.  May need a large rubber hammer/ mallet to tap the mounting brackets to loosen.  Lower the axle to the in place furniture dollies and slide side ways out from under the rv. Installation, is the reverse.

This is a simple operation and working by my self was accomplished in several hours.  

THE MAIN THING TO ALWAYS REMEMBER,  CAUTION,  BE EXTREMELY CAREFUL WHEN WORKING AROUND AND UNDER THE SUPPORTED RV!!!!!!

Amazonica

Nicely done! Great shop too - I am a bit envious. 😄

B0atguy

Hey @atlasb , 
Just a quick question on the wiring . The new boondock axle I just received , it appears , they went a little heavy on the paint and completely painted the 10" leads of brake wiring . I can find no colors identifing the wires (2 on each side) . Is there a specific orientation of how these wires must be wired up ? Is a certain wire supposed to be the ground , or does the polarity not matter ? 

Thanks ! 

MuttonChops

B0atguy said:

Is there a specific orientation of how these wires must be wired up ? Is a certain wire supposed to be the ground , or does the polarity not matter ?

I've been eavesdropping on your axle project for awhile so will comment even if question was not directed to me . . .

Electric brake electromagnets have no polarity.  You can connect either wire to the Blue Source or the ground.

For reference, etrailer help posting:

https://www.etrailer.com/question-6114.html

B0atguy

Thanks @MuttonChops . At least I know I wont burn up the electromagnets or something if I hook them up incorrectly now , lol . 
Thanks for the link ........

atlasb

Hey BOatguy,  Exactly what I was trying to figure when I got our new axle.  I seached and did not find a definite answer.  Being a guy,  I watched how I cut the current wires on the 400 with the least amount of splices and wired it back up.  Fingers crossed.  It worked but I had very little reading on my P3 controller.  I adjusted the brakes on the new axle and towed it a few miles them re set the brakes.  All is well in the home front now.  Atlasb

jimcenname

I notice you covered the large openings in the frame fore and aft of the axle. i did as well using similar technique. I am trying to imagine if there is downside to doing this. What the heck were they for anyway, Hard to believe it was to reduce frame weight. Access holes? to what?

atlasb

I covered 2 and put a vent screen on 2.  I left the 2 with the screen in case of any propane leak.  I think they are for to make the frame a little lighter.  the frame is fairly light in it's own.  With the lip around they retain most of the strength from removing any material.  Not much that you can really access through them.  I wanted to help prevent some dirt and debris from building up under there.  Some have dropped the belly pan and added some foam insulation under there.

Submariner

So will this work on a 17 T@B CS-S? 

Denny16

@Submariner You can contact nüCamp Customer Service and get the correct boondock axle recommendation (was called the Outback then and was available on a 2016 model) for your 2017 TaB320.

Cheers

BurritoLover

@atlasb Great info! Do you know how much your axle mod raised the frame? I'm not finding consistent numbers on the clearance difference between the boondock and standard models.

Denny16

Ours was raised between 3 to 4 inches higher after the Boondock axle was bolted in.  It makes a noticeable difference, and increases the approach and departure angles of the trailer.
 Cheers