O235 Push Rod SB

[04ZULU]

I've been working on doing a top overhaul on my Colt w/ O235C1B lately. While cleaning the push rods I discovered a crack near the end. So searching around I discovered that there is a SB that the aluminum push rods are to be replaced at overhaul or removal.

I have called a local Lycoming parts supplier and they say the old part number is 73806 and the replacement all steel push rod p/n is 15L22200. The length for these part numbers is 11.558". My old push rods measure 11.805". The parts list seems to lump the newer O235 engines with the older ones with solid lifters.....I think there must be a different P/N for the C1B push rods, because I think a 1/4 inch difference in length will be a problem when adjusting the rockers that far. My supplier said they talked to Lycoming......

Does anyone here have experience changing to the newer steel push rods or have info. on this problem? Thoughts on this would be great.

[Vagabondblues]

Lycoming SI 1060 has this note about the 235 series
NOTE
Old part numbers may be used interchangeably with equivalent new part number (except on O-235 engines, refer to latest revision of Service Instruction No. 1480).

Todd

[04ZULU]

I just discovered an obsolete parts list for the O235 on a CD someone gave me. The new push rods require a different adjustment screw (p/n 73807) in the rocker arm to go with the new shorter push rod p/n 15F22200 or old p/n 73806.

Well, if someone else is looking into this maybe they will find this helpful.

[Steve Pierce]

Interesting. Thanks for posting this. I have worked on a lot of O-235C series but never run into the aluminum push rods. Now I know what it will take to fix. Thanks.