DG Flugzeugbau GmbH
Postfach 1480 76604 Bruchsal
Tel. 07251 3020-0

Working instruction No. 2 for TN 873/12

A) Replacement of the return spring of the muffler lifting cable (which lifts the muffler during engine extension) by a rubber cord
See drawing 8EP235
1.	Remove the existing spring. To accomplish this remove the upper mounting bolt of the muffler stop where the spring is fixed, don’t lose the bush.
2.	Remove the ring which fixes the spring to the muffler lifting cable, using a wire cutter.
3.	Install the thimble to the lifting cable, lay the 2mm rubber cord around the thimble, make a knot and slide the silicone hose over both ends of the rubber cord, make further knots according to the drawing and fix with ty-raps.
4.	Slide the rear loop of the rubber cord over the bush see 1. and reinstall bush and bolt, secure with Loctite 243.

B) Inspection and alignment of the exhaust system
In most DG-800B’s the front end of the muffler is located too far to the left hand side. When coupling with the manifold the front end of the muffler is pressed to the right hand side. This causes lateral forces to the exhaust manifold which might result in fatigue cracks. By the instructions mentioned below the muffler is shifted to the right hand side, which lowers the lateral forces to the exhaust manifold. 

1.	Check the exhaust manifold for cracks. If cracks appear it is most likely that they are on the left hand side of the manifold and can be detected without removing the manifold only with mirror and torch.
2.	I there are cracks, the manifold must be replaced.
Note: The fixing bolts are secured by the securing washers underneath the bolt heads.
3.	Unscrew the suspension bolt of the front-left hand suspension spring in the in the muffler frame. Install a longer bolt m8x30 DIN 912-8.8zn and add a nut M8 DIN 934 Stzn between spring and frame. Secure the bolt with Loctite 243.
4.	Check the spring pressure at the coupling of exhaust manifold to muffler. To accomplish this, measure the distance between the brackets for the spring couplings at the muffler pipe and at the movable part of the muffler in disengaged and in operating position using a slide gage. Extend the powerplant to operating position via the ignition switch. As soon as the extension stops, lift the red cover of the manual extension switch and switch off the ignition. In operating position the distance should be 1 – 4 mm (0.04 - 0.16 in.) smaller than when disengaged. If the difference should be less you have to adjust to min. 1mm using the nut on the eyebolt. By this you will pull the muffler forwards in its frame.
5.	Material
A	B	If necessary	
thimble HC2
0,85 m rubber cord 2mm
0,25 m Silicone hase
4 pieces ty-raps	nut M8 DIN 934-8 zn
bolt M8x30 Din 912-8.8 zn	exhaust manifold 8M269
2 gaskets for exhaust manifold	
		Loctite 243, not contained in the retrofit kit	

Issued March 9. 1999	Author: W. Dirks