Removed Stock Muffler

Jammer

Well-Known Member
First Name
Jeff
Joined
Mar 9, 2018
Messages
2,375
Reaction score
599
Location
Ft worth
Vehicle(s)
Bright white JL Rubicon
$89.95 shipped free from summit racing
I never heard about this problem I don't have that problem on the flowmaster. And when Eddie from [Banned Site] put the dynaflow on his he didn't show having to do this but he and I both have 2018 isn't it the same pipe for 2018 and 2019 or are they different ?





Advertisement

 

blnewt

Well-Known Member
First Name
Brad
Joined
Oct 8, 2018
Messages
4,335
Reaction score
4,273
Location
New Mexico
Vehicle(s)
2019 Jeep JL Sport S, 03 Toyota 4Runner, Infiniti G37, Toyota T100 (Retired 74 CJ-5, 80 CJ-7)
Here's that stud that interferes w/ the Dynomax install. I went ahead and ground a notch out of the Dynomax so it fully seats in the same location as the oem muffler pipe, I didn't hear any exhaust leak prior, but there was some exhaust soot exiting at that point and now that it's fully seated I did notice a cleaner exhaust note, so there was exhaust leaking there. so glad you guys pointed this out, back to happy again!

100_4118.JPG


100_4120.JPG


100_4121.JPG
 

Jammer

Well-Known Member
First Name
Jeff
Joined
Mar 9, 2018
Messages
2,375
Reaction score
599
Location
Ft worth
Vehicle(s)
Bright white JL Rubicon
Here's that stud that interferes w/ the Dynomax install. I went ahead and ground a notch out of the Dynomax so it fully seats in the same location as the oem muffler pipe, I didn't hear any exhaust leak prior, but there was some exhaust soot exiting at that point and now that it's fully seated I did notice a cleaner exhaust note, so there was exhaust leaking there. so glad you guys pointed this out, back to happy again!

100_4118.JPG


100_4120.JPG


100_4121.JPG
You haven't heard about this problem with the flomax pipe have you ? that's like this?
 

blnewt

Well-Known Member
First Name
Brad
Joined
Oct 8, 2018
Messages
4,335
Reaction score
4,273
Location
New Mexico
Vehicle(s)
2019 Jeep JL Sport S, 03 Toyota 4Runner, Infiniti G37, Toyota T100 (Retired 74 CJ-5, 80 CJ-7)
You'd have to take a look up there and see if yours has a notch cut out. This was news to me up until that post on the last page :)
 

mikej

Well-Known Member
First Name
Mike
Joined
Jun 30, 2018
Messages
628
Reaction score
680
Location
California
Vehicle(s)
2018 JLUR
Installed my Dynomax delete today and had the same issue where I needed to cut a 10mm notch (with a Dremel). I have a July build 2018 3.6, so I have to believe more have the issue with needing to cut a notch than not. After I cut the notch, the new pipe covers exactly the same amount of upstream pipe as the stock muffler did.

I’m not sure why Dynomax doesn’t ship with this notch in the first place.

4DB09F2C-04AF-4DCB-88A8-8927ED8EAC11.jpeg
 

mikej

Well-Known Member
First Name
Mike
Joined
Jun 30, 2018
Messages
628
Reaction score
680
Location
California
Vehicle(s)
2018 JLUR
Nope, it was loud and just didn’t sound right. I’ve gone back to stock for now. While I was under there, I grabbed a few more shots that might be useful for folks, including the anti-rotation nub.

BE47663D-9112-4C72-9E86-57D516EE6B05.jpeg


7436D356-DAF2-441B-9496-46801F042D27.jpeg


821B7787-E3C3-4CFB-A46F-CD5525B38FE7.jpeg


D949F86D-CB7A-4C1B-9AE9-6ED3FB359A87.jpeg


CAA1B626-D2EC-4037-B05B-26EDD5622921.jpeg
 

Eduardo909

Active Member
First Name
Eduardo
Joined
May 6, 2019
Messages
32
Reaction score
22
Location
San Bernardino
Vehicle(s)
2019 JL MOAB
Installed Dynomax delete today, didn’t notice about the notch until reading this thread. I just went back under the Jeep while on and felt a small flow of air in the upper part where the nub is. How dangerous is this? Love the sound, don’t really want to go back to stock.
 

mikej

Well-Known Member
First Name
Mike
Joined
Jun 30, 2018
Messages
628
Reaction score
680
Location
California
Vehicle(s)
2018 JLUR
Installed Dynomax delete today, didn’t notice about the notch until reading this thread. I just went back under the Jeep while on and felt a small flow of air in the upper part where the nub is. How dangerous is this? Love the sound, don’t really want to go back to stock.
It’s worth fixing. It isn’t too hard if you have a Dremel. And if you don’t, a cheap, small hacksaw from Home Depot would do the job. Take a Sharpee and crawl back under your Jeep. Draw two lines where the nub is (give yourself a bit extra space) and then pull the delete pipe. Cut two lines about half an inch in, and then use pliers to bend/break the extra metal. Pop the delete pipe back on with the nub in your new slot and tighten everything down. That should take care of that extra flow and you can still enjoy the sound.
 

blnewt

Well-Known Member
First Name
Brad
Joined
Oct 8, 2018
Messages
4,335
Reaction score
4,273
Location
New Mexico
Vehicle(s)
2019 Jeep JL Sport S, 03 Toyota 4Runner, Infiniti G37, Toyota T100 (Retired 74 CJ-5, 80 CJ-7)
It’s worth fixing. It isn’t too hard if you have a Dremel. And if you don’t, a cheap, small hacksaw from Home Depot would do the job. Take a Sharpee and crawl back under your Jeep. Draw two lines where the nub is (give yourself a bit extra space) and then pull the delete pipe. Cut two lines about half an inch in, and then use pliers to bend/break the extra metal. Pop the delete pipe back on with the nub in your new slot and tighten everything down. That should take care of that extra flow and you can still enjoy the sound.
This^^^
I just used an angle grinder to get that notch out, took just a few minutes to remove and modify and reinstall. Also be sure to remove any burrs from grinding/cutting that may be on the inside of that pipe after cutting, don't want anything affecting a smooth mounting surface.
 

Eduardo909

Active Member
First Name
Eduardo
Joined
May 6, 2019
Messages
32
Reaction score
22
Location
San Bernardino
Vehicle(s)
2019 JL MOAB
It’s worth fixing. It isn’t too hard if you have a Dremel. And if you don’t, a cheap, small hacksaw from Home Depot would do the job. Take a Sharpee and crawl back under your Jeep. Draw two lines where the nub is (give yourself a bit extra space) and then pull the delete pipe. Cut two lines about half an inch in, and then use pliers to bend/break the extra metal. Pop the delete pipe back on with the nub in your new slot and tighten everything down. That should take care of that extra flow and you can still enjoy the sound.
Yeah I would have to buy a hacksaw to cut the metal. How about using a muffler/tailpipe sealer at the connection? The dynomax pipe is secured enough and this should seal any leaks. I attached a screenshot of the sealer.

B68402FE-B267-4E27-9A71-436263A2AE2C.png
 

Eduardo909

Active Member
First Name
Eduardo
Joined
May 6, 2019
Messages
32
Reaction score
22
Location
San Bernardino
Vehicle(s)
2019 JL MOAB
So I cut the notch, put the exhaust all the way in, tighten the clamp as much as it would go and can still feel quite a flow of air coming out of the connection. Same as before I cut the notch or even more. I took some pics.

AAEB208C-2B88-43C8-8ADC-57EF97DE79F8.jpeg


D0581418-A5F1-4608-B13C-AEEE4CACAF80.jpeg


548832E3-2AD7-4538-BE4B-D3D8A7947AAE.jpeg
 

mikej

Well-Known Member
First Name
Mike
Joined
Jun 30, 2018
Messages
628
Reaction score
680
Location
California
Vehicle(s)
2018 JLUR
So I cut the notch, put the exhaust all the way in, tighten the clamp as much as it would go and can still feel quite a flow of air coming out of the connection. Same as before I cut the notch or even more. I took some pics.
I'm surprised. It looks like you can't get it any tighter. I can't say that I had that issue. I know the price just keeps adding up here, but maybe take it to an exhaust shop?
 

blnewt

Well-Known Member
First Name
Brad
Joined
Oct 8, 2018
Messages
4,335
Reaction score
4,273
Location
New Mexico
Vehicle(s)
2019 Jeep JL Sport S, 03 Toyota 4Runner, Infiniti G37, Toyota T100 (Retired 74 CJ-5, 80 CJ-7)
Eduardo, the clamp appears to be angled in the first pic, might try to loosen the clamp and try to get it on so the edge of the clamp is even all the way around, would get more uniform clamping that way, if that still isn't working then that sealant might be a plan.
 

JLUin818

Well-Known Member
First Name
Steve
Joined
May 29, 2018
Messages
1,919
Reaction score
2,106
Location
San Fernando Valley
Vehicle(s)
2018 JLU
i literally just finished installing they dynomax muffler delete 15 minutes ago and then saw this tread. back to go yank it off. :angry:
 

JLUin818

Well-Known Member
First Name
Steve
Joined
May 29, 2018
Messages
1,919
Reaction score
2,106
Location
San Fernando Valley
Vehicle(s)
2018 JLU
I wonder if dynomax shortened the pipe to address this issue. I have my pipe all the way on and its at least a quarter inch away from that nub. To get it to cover that nub i would have to twist the hell out of the stock hanger rubber

0ACAC5F5-A79E-4695-881F-ADFD32BE2F6D.jpeg


75F58E27-D2B7-40EB-B044-B84DBC076BB5.jpeg


7DF16921-E8F5-49CD-A9A5-83D3A6A20A65.jpeg
 

Advertisement




Winjet
 



Advertisement
Top