New Towd

Time to start working at getting the new to me Jeep ready to be towed.

Atwood 15.5k A/C install

My GMC motorhome has a heat problem.   The windows are great for seeing out, and feeling like I am out in the open, but when the sun hits it turns into a green house.   Someday, I think insulation, and tinting the windows will be the best way to solve that problem,  but there is also an issue with my roof A/C units, so I am fixing that this spring.   My coach has two original duo-therm A/C units on it.  And they have both worked at one time.   The rear one, had an issue with a capacitor, and i fixed that, only to have it quit blowing cold air later in the year.  My front one always has worked,  but it us super loud, and I have to make sure i am plugged into a higher capacity electrical service, and use a heavy duty cord.   So the last year, I have been researching A/C units, and I have decided on the Atwood Air-Command 15.5K unit.  It is advertised as an energy saver, with better cooling output, and the specs does show it amps at running are the lowest I have seen compared to other manufacturers.

so here is my pictures of the swap.  I decided to move my working front A/C unit to the rear, discard the rear A/C rather then figuring out why it does not blow cold air anymore.  And the Atwood will go in the front as our Main unit.


I work at a great place, and i was able to bring my Coach to our shop, and utilize a forklift.  It made the job so much easier and safer.

Remove Box,  and 4 bolts,  and it pulls up.  The original has this big metal plate glued down to the roof, and another plate inside.  This is the original A/C  tilted forward.

removing the top plate, took some prying, and it left a silicon mess, and that black tar was a real pain to clean up.  Mineral spirits broke it down, but it took alot of towels and time.  and it got everywhere!  The lower metal piece has a lip that goes under the headliner material about 1" on all 4 sides.  We ended up cutting it apart to get it out.

Rear A/C removed.   I am glad not to have to remove this base plate

Underside of original A/C unit.  

Finally Cleaned up,  and ready for new one to go in.

forklift really made this job pretty easy.   no back straining!

for the GMC motorhome,  I was told on GMCnet what size bolts to buy, because we have such a thin ceiling thickness.  otherwise you have to cut down the ones that come with the Atwood.  The lower black plastic bolts up nice to the Atwood top portion.  This picture also shows the little plenum duct that you cut to size, that goes between the upper unit, and the lower inside plastic.

Picture of the bolt going into the upper unit nut insert.  each one was real tight to the corners of the hole, but was a perfect fit.

picture from other side, also showing the short duct.

Installed

Back of unit.  Plastic shroud is not as sturdy as our original.  

Front.  

Inside.  i am not a fan of the flip down controls, but I will live with them.

Flo-Pro 1953 muffler for the onan

I have patched up my original onan muffler a few times with the mig welder.  It is getting pretty thin, and with my new A/C unit, I want to be able to run the onan more often without worry.   I searched and decided to buy and install an alternative Muffler.

Flo-pro 1953 muffler bought online from Bumper Super Store.com

$61.32

removed down tube and old muffler.   I also replaced the exhaust manifold gasket.

Comparison of the two mufflers

On the original setup,  the downpipe went over the entrance pipe to the muffler.

my downpipe was not terrible.  I cut a little rust off the end, and used a wire wheel to clean it up.  the rest of the pipe feels pretty solid.

on the new muffler, the opposite fit works great.   The downpipe fits nice inside the inlet pipe of the muffler.

Test fit,  it looks like it will be just right.

Final Fit before Welding the bracket.   I cut the bracket off the old muffler.  Heated red hot with torch, and pounded it with hammer to countour to the new muffler.  a quick hit with the Welder and it will be just right.   I also cut 4 slots into the inlet of the muffler, so it will clamp down tight.

Very close to the onan box,  but it fit very well.  I think I am going to add some more exhaust pipe.

This is DB reading from inside hallway with old muffler

DB reading inside hallway with new muffler.  It is a bit louder.

DB reading of original muffler outside

DB reading new muffler outside

As you can see by my DB readings from my iphone app, it is a little bit Louder.   However, looking at how the muffler is installed, I think by adding some more exhaust piping to it to direct the noise down and away a little bit, I think I will see another drop.  this muffler is 1.5" outlet, and I can find muffler pipe in that size. 

  Update.....   I installed about 8" of tail pipe,  with part of a 90 degree elbow.  it made all the difference.  You hear both the engine noise, as well as exhaust noise now.   This little piece of pipe quieted it down quite a bit.

Ended up 1 db quieter outside

Same as old muffler now inside.