Reinstall Rear Engine Exhaust

[fsnewton]

Howdy guys,

I recently overhauled my rear engine in my pressurized 1973 T337G. When my IA removed the exhaust system he noticed an excessive high load on the bolts used to attach the system to the engine. When we went to reinstall the exhaust stack we decided the amount of “torquing” on the system was excessive and must not be either a) installed correctly or b) the pieces are incorrect. We replaced all of the parts using Acorn but we had the same poor fit issue with their parts. If everything is on correctly, we have a misalignment at the pilot side collector (see pic). Are we missing something?

Thanks,
Scott

[Dan schultz]

I am finishing mine all parts are also Acorn. You should be able to pull the ball joint half up and bolt it in with the 3 bolts. Check all the rubber mounts in the turbo bracket that attaches on both sides of the engine.

Dan

[fsnewton]

Thanks Dan. Are you also an early P-model? No issues with your install?

[Dan schultz]

74 model, had to send a few parts back, number 3 riser did not fit to the collector correctly, I would say loosen everything up, attach the ball joints and go from there. Make sure the rubber mounts are not worn out.

This would include loosening the bolts on the turbo to the main turbo bracket, there is some play there. All parts including tailpipe need to be on and loose.
Dan

[Dan schultz]

Sending my collectors and receivers back to Acorn, ball joints leaking like a sieve. No need for soapy water. Hooked up the shop vac to the tailpipe whistling crazy air from the joints.

I did fly the aircraft the other day finally after 2.5 years, all things worked pretty well.

Dan
N67S

[Dan schultz]

Learning a few things about the exhaust ball joints. Paul at Acorn has verified through Cessna. The three bolts at the joints are 1550177, basically an AN3-14A that has threads down to a .5 grip and the springs are supposed to be compressed to a .5 length.

The parts manual shows on the left side bolt, then on the top flange washer, spring washer, nut ms20364-1032c, no castle nut or cotter pin.

The right side has a bolt, washer at the head of the bolt, on the top flange washer, spring, washer, then the lock nut.

The maintenance manual says bolts with castle nuts and cotter pins which obviously is the aircraft with ball joints prior to the P models, a change that was never made to the maintenance manual.

[Dan schultz]

Exhaust is on its way back from Acorn, we will see how those ball joints are now.

Dan