Strjock81

Wanted to thank you guys for recommending the Donaldson 36" muffler, put it on last night and it is even better than i expected. little louder under acceleration, more turbo whistle, and a SOTP improvement in response/turbo spool up. When cruising there is no drone (less even than stock IMO) and it is quiet enough I hear the road noise, not exhaust or engine noise. Went through town last night, pretty throaty rumble with some turbo mixed in bouncing back off the buildings. Install was a breeze!

cquestad

Which way did you mount it...arrow pointing forward or back?

Strjock81

mounted it the way it was supposed to be, arrow pointing forward to inlet. Plenty loud that way for me under acceleration, with expansion chamber rearward.

Hoss

Does it sound like a ricer??

cquestad

Mine sounds like a big rig...with it mounted backwards on accident. I think it would sound deeper with it mounted the "correct" way.

Hoss

Hmmmm....so which way sounds better??

cquestad

Somebody needs to check before welding on the hangers...



I might reverse it someday and see for myself...but not for a while. To busy...

03CumminZ4X4

I want to thank you guys for the recomendation for the Donaldson muffler. I could not find the Donaldson 34'' so I had the parts man at Fleetpride cross it to a Nelson. Just installed it yesterday. It sounds great!! One thing I did notice is that there is no flow direction on the muffler and the expansion chamber on the Nelson is positioned in the center of the muffler instead of toward one end? If anyone has any info on the difference in the position of the two and what difference this makes please post!Dont have the Donaldson to compare sounds of course but I couldnt be happier with the Nelson. Big rig sound and no drone anywhere!! Thanks again!

MonkeyLips

Could you reply with the actual # of the mufflers?

03CumminZ4X4

The # for the Nelson I installed is 86127M.

jwtuc

Could you give some installation info? I ordered a 34'' but took it back . I took it to a muffler shop for installation and the installer talked me out of installing it. He showed me the allignment problems and said that he could make it work with two 45 degree turns . I chose not to do it . I guess there is more room on 03s without the cat in the way . DPP is in the process of putting a cat back system on the market and are taking advance orders.

03CumminZ4X4

Two 4'' and one 3.5'' muffler clamps, one 3.5'' to 4'' adapter, torch for heating stock pipe to get the stock muffler off after being pinched by the factory clamps, position the new muffler, clamp in place. I heated the mid pipe joint to get it to rotate about 45 degrees so the front of the muffler would not hang down below the frame. A torch is a real time saver!!!!! Oh yea I had a muffler shop guy tell me the same thing. Dont listen to them. I have about 85 bucks in the whole thing and love it!!! Just do it you wont be sorry!!

Mark65

I mounted mine on a 2004.5, "600" Jwtac.....Sounds Great! I did have some alignment problems, but you just have to clamp the front of the muffler tight and twist the tail-pipe until it is where you want it.

rjweiss

What's the part number for the Donaldson? and where do you purchase one?

Thanks

Ron W.

OT-OF-Here

The part number you seek I don't know, but for a really great price call your local Freightliner dealer. I priced a 40" for $51 and tax. I've got a 26" on order,..should be here tomorrow. Don't know the part numbers though. Would have mine tomorrow if anyone needs it.