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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Flyboy on August 04, 2008, 01:54:41 AM

Title: Changing muffler on 4104.
Post by: Flyboy on August 04, 2008, 01:54:41 AM
I need to replace one of my cans on my 4104 (6N71).  Detroit dealer quoted me 13 hours labour to do the job.  Said I have to remove the engine to replace it.  It's the outside muffler closest to the rad.  Is there another way of doing this that is less costly?

Aron.
Title: Re: Changing muffler on 4104.
Post by: Glenn MC9 on August 04, 2008, 03:52:19 AM
Replacing a muffler is time consuming, but not 13 hours. I replaced both mufflers on our 04 and it took about four hours without removing the engine! Most shops that's not setup to work on coaches will charge you a "arm and a leg".

Anyway, I went in through the two access holes where the rear bench seat was. It's a little tight, but it can be done. If you're lucky, you'll have a two piece manifold to make it even easier.

Glenn
Tallulah Falls, GA 
Title: Re: Changing muffler on 4104.
Post by: tekebird on August 04, 2008, 07:08:56 AM
flyboy,  I suggest you find yourself a bus mechanic or shop with GM experience.

a Detroit dealer is no pl;ace to take a bus or your 6-71 anymore.

as the last post stated to correct way is through the rear access
Title: Re: Changing muffler on 4104.
Post by: Flyboy on August 04, 2008, 08:56:51 PM
Thanks Glen...

I will have a look at what's involved and go that way.

Tekebird...I hear yah on the DD shops.  Got a good mechanic here in Kelowna.  The DD guy was in Reno on our way home from Phoenix.  That was an tow in experience that involved only what it took to get back on the road.  Long story better shared over beverages at a rally!! :o  Thank God for Good Sam.  Best $79 I ever spent.

Aron.
Title: Re: Changing muffler on 4104.
Post by: JohnEd on August 04, 2008, 09:12:23 PM
04 muffler failure,

Isn't that the coach that burns itself down(or up) when the muffler leaks?  ???  :'( Something about hot gasses "squirting" on the plywood floor. :o  Didn't pay all that much attention at the time. :P  Now I firmly believe that an exhaust pipe clamp is an exhaust pipe clamp....but. 8)  Is that the reason for the advice to find a reputable mech to replace a friggen muffler?  ???  May be more here than meets the eye....or plywood.

HTH,

John ;D ;D ;D
Title: Re: Changing muffler on 4104.
Post by: gus on August 05, 2008, 05:46:42 PM
Aron,

The 4104 dual mufflers come out through the top of the small door at the top of the firewall. It was originally under the rear bus seat bus is now usually covered by wood and insulation.

It is a tight squeeze for the original mufflers. I replaced mine by much smaller ones I got from JCW and altered to fit. 

I did this because the originals are so big they are hard to handle and the original design has a ridge at the top that just begs to collect water and rust out. This is the place that gets holes and burns up 4104s.

I highly recommend that you replace both while you're at it.

Scott Davis is going through this very job right now and I sent him all the info and drawings I made up for mine.