perfect777

Hey everyone!

I've had DMH "low profile" electric exhaust cutouts installed on my V for over 3 years now (probably 25k miles since installation). They have absolutely been my favorite mod that I've done to the car (in combination with my headers and cat-deletes). Smiles/$$$ - the cutouts are the best investment I have ever made.

Unfortunately, unless I'm intentionally opening the cutouts (which I do a lot for obvious reasons), the cutouts don't seem to close very well anymore. As soon as I take my finger off of the [momentary] switch to close them the cutouts will immediately re-open a bit and make the car sound like a clapped out old camaro or something. I know that DMH has a poor reputation for service to customers (4 year warranty is only good if you can actually get a hold of him) - so I'm hoping some folks in the V community can help me fix this issue. I really don't want to remove the cutouts for good and cap the flanges...they are just too much fun. But I'm getting sick of pulling up next to cars and feeling like I'm driving a busted POS rather than the brute Cadillac that this is supposed to be.

So here is my problem. The butterfly "gate" doesn't seem to want to stay shut in the "closed" position. The butterfly gate is mounted to a spindle that sticks is inserted into the gate flange. One end of the spindle stops at the end of the flange, the other end of the spindle attached to a coupler that is part of the motor unit. I can very clearly see that (even with the cutouts in the "closed" position) that the spindle has some play in the valve flange. It's not much play, but enough that I think it clearly demonstrates that the powerful air pressure of the exhaust can force the valve to crack open and create the rattle.

I've posted two videos that explain what I'm talking about:

Video 1

Video 2

I've seen a few threads over the last few years where people have mentioned that there are some screws that work there way out (in the motor housing) and can be drilled out and replaced. I'm not really convinced that the motor housing is causing the problem - unless the motor is supposed to be providing some additional tension that forces the valve to seat closed and stay closed. I haven't drilled out the rivets to investigate because I wanted to get some input from the forums on if my loose spindle/flange is causing the rattle. If tension is required to seat the valve, then I guess I have no choice but to drill the rivets out and try to fix them.

http://www.lxforums.com/board/showth...eak-rattle-fix
https://ls1tech.com/forums/generatio...-pictures.html

Thanks for your input!

jsteele90

iTrader: (13)

Ive had to do this twice with my qtp cutouts. First time the setscrews for the butterfly valve came loose. I added some red loctite and they were good for like 8 months. Second time the setscrews came out. So i drilled all the way through and ran a bigger screw in with loctite. I kniw it wont be an issue now.

perfect777

What setscrews are you referring to? The setscrew that holds the spindle to the coupler?

Becker

iTrader: (4)

I suggest disassembling one and cleaning it completely and installing all screws with red loctite. Go through it from top to bottom and you might find the issue, if not clean it well and tighten it all up and compare the freshly cleaned one to the older dirty one.

Thats what I would do if they were on my car.

perfect777

That's definitely my next step. I just don't get any play in the motor housing/coupling connection [to the spindle of the valve that is moving].

jsteele90

iTrader: (13)

Yes, there are two setscrews on mine that connected the motor to the shaft that the butterfly was attached too. When they loosened up it would still open and close but wouldnt stay tight because those screws where allowing it to slip.

Becker

iTrader: (4)

A buddy of mine had an issue with a throttle body doing the same.. turned out his set screws were slightly off.. A good clean and quick align and tighten and it was buttery smooth again.

I understand this is a different story and these parts live in a different atmosphere. But it's worth a shot

perfect777

Well I drilled out the rivets on one and tightened down the two motor screws) the only two screws that I could really see. I re-aligned everything and bolted it all back together. I couldn't push the butterfly gate backwards and forwards like I did in the 2nd video...so I was optimistic that the results would be good.

Of course, as soon as I started it up the exhaust forced the gate to open slightly and I'm back to square one...still leaking/rattling. The gate just has too much play in it to stay in one place. I wonder if I could shim in tight to stop the back-n-forth play that the gate spindle has against the gate flange.

Becker

iTrader: (4)

I wonder if the gear mech is just worn out. Depending on how it operates it may be a gear spinning which is worn on one side due to the use its been. Through. If it is a the problem you could maybe flip the gear to use the other side.

I'm just spit balling here. Sorry

Onefast V

iTrader: (3)

I have the same issue and i'm fair certain the drive gear is just worn and needs to be replaced.

randy129

iTrader: (5)

You're right on the four year warranty and that it's *impossible* to get in touch with him. I definitely wouldn't recommend sending them back to DMH for repair/swap. He's had my cutouts since for about six or seven weeks and will not respond to email or phone calls. Not sure what's going on with him, but zero communication is not way to stay in business.

perfect777

I would love to give the guy the benefit of the doubt but I have literally lost count of the number of people who have said the same exact thing.

How were yours rattling? Mine really seem to be tight at the motor..the spindle just has a lot of play in the gate flange.

Does anybody know how to remove the spindle? I can remove the butterfly portion by removing the 3 torx screws, but the spindle appears to be pressed into place...

randy129

iTrader: (5)

I don't know him, so I can't say for sure, but maybe he's just in over his head running a one-man show? Don't have mine to look at, but it's certainly possible they're pressed in.