First annual
 

Well it's been almost a year since I purchased my first 337 , It's a 1965 A I got form a guy at Norwalk Ohio Jan 2nd 2006. The annual ran out Oct. 31st and my mechs have found out two major AD's that have been not complied with for many years. This was a lesson to me not to take any mechs word from the log book. I found out that the mech that has signed off the annuals for the last 15 years would not know what color the plane was. The first thing was the front mags had an AD and my lead mech suggested new slick mags. Then we learned the slick mags are not STCed for the IO360s in 337s even though they are used in piper twins. So the slicks came with new wire harness and 18 autolite plugs, we had to send them back and purchase bendix for about $900 more and then a wire harnes for $465 and then plugs for $250. Or about $1600 more. Then we found the front prop had an AD not complied with. The book said it was, but my mechs said better remove it and have it overhauled . H&S prop shop found it in very poor shape and the prop needed to be overhauled and the hub was shot. Hubs are very hard to find and thanks to Herb Harney, he had a serviceable hub and that problem is taken care of. About $4000 and the prop looks great. My problem now is the tach sending unit will not work that is on the right front mag. We lost one wire off it and tried repairing it and have had no luck getting it to work. I have called all over pricing new ones. I just want to be sure the mechs have installed it in the right outlet of the mag. The first try we had continuity, didn't work so the tried again without continuity. Its may be junk now anyway. If any one can help me let me know. Ed

Hello Ed
The Tacho wires into the breaker plug of the mag, there should be 2 wires, one is a ground which goes back to the ground pin of the tachometer and the breaker wire which goes back to the Tan coloured wirs on the tachometer, there is a noise filter in between mounted on the firewall, check that this is ok and no wires are off it.

Regards
Pete

Tach
 

Pete, Correct me if I am wrong, but I think a 1965 model uses a pickup screwed into the bottom of the mag, & they are hard to find !!!!!
Fred N358

Yes of course it is Fred, read his a/c type wrong. But from the mag the tacho wiring is the same.

Pete

Thanks for the help. The new tack pickup is on order. I hope it works the way we will hook it up, then I'll have the annual signed off and ready for spring.

Hi Ed, I also have an intermittent tach problem which I believe originates with broken strands in the wires as they leave the pick-up. I would be interested to know where you ordered the pick-ups from, what the cost is and whether you know if they can be removed and replaced from the mag without removing the mag or the alternator from the case. Thanks for any information you can provide. Steve G.

Hi Steve. The place I ordered the tach pickup( or coil ) was Edgcumbe in Ky. @ 1-800-621-1319, Lists for $524.96 and they can ship one from continental-Bendex of Alabama. Their price is $393.72 plus freight. You might take some epoxy glue and get a gob over the head of the unit so as to stop the movement of the very lite wires coming out of the sending unit or coil. This will stop the blast of cooling air from wiggling the wires and breaking them off. Also will protect the when the mags are handled. Ed.