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Street Race Truck More... The Toolbox

How to Install an Electric Motor Kit for Exhaust Cutouts


A very common problem occurs whenever you add electric cutouts to your exhaust. The electric motors used just were not designed to hold up to the heat from the exhaust and some use a plastic gear in the motors for opening and closing the cutout. This is just a failure waiting to happen. I installed Doug's Headers electric cutouts on my vehicle and within a couple years the right-side cutout stuck open and would not close. The electric motor gave out. So, what to do to fix this? Pretty easy solution as Speedway Motors sells the replacement electric motors under part number 447900.

There are cheaper replacement motors out in the aftermarket however the adage you get what you pay for comes into play. Also, Doug's Headers uses a high torque gear reduction motor for quick opening and closing of the cutout. And since I only had the right side go out, I want to match the speed at which they open and close. Replacement of the motor is surprisingly easy, and I opted to change it without removing any exhaust.

With my vehicle firmly supported in the air on jack stands I unplugged the old motor and removed the 6 Philips head screws that hold the cutout plate together.

There is one screw tucked in by the Y pipe that can be difficult to get to.

I luckily had a small 90-degree handle ratcheting screwdriver that worked perfectly for this. There are two spacers sandwiched between the cutout plates that are held in place by the Philips screws. These will fall out easy once separated and they will only install one way as the shape of them is specific to where they locate.

With the cutout plate removed you can see how much build up accumulates quickly from the exhaust.

Now to change the electric motor which is held in place with 3 recessed Philips head screws and the gate plate that rests on a roll pin in the shaft of the motor. Remove the roll pin by pressing it out carefully with pliers or the tool of your choice.

Reassembly is just the reverse of disassembly. I cleaned everything up with some good old-fashioned brake clean and a rag, fastened the new motor in place and installed the roll pin from the old motor to the new one. Back under the car I made sure the switch was in the closed position and rotated the gate closed on the cutout to match open and closed. Sandwiching the two pieces back together does take some patience since you have two spacers, and the gate is only held in place by the slot in the gate plate and roll pin in the motor. The nice thing is it can only go back together one way. With all the screws back in place and the cutout in one piece again I hit the switch and it opened and closed perfectly again.

However, my curiosity was still as to why it gave out. So, I took the old motor apart and found that one of the gears in the gear pack had stripped the teeth on one side, only allowing the motor to close halfway. After cleaning the grease off the gears, I found out why. The one gear that stripped was made from a plastic material while all the other gears were metal.

So, in the future I may try to source a replacement cast or brass gear or motor without a plastic gear as a fix for this. But for now, my cutout is functioning as it should again, and the replacement motor was a direct fit for easy replacement.

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