Lycoming O320 A2B Cylinder wrenches

[Jermechanic]

I will be pulling a cylinder from my narrow deck O-320A2B. It has the hex type internal thread cylinder base nuts.

Am I correct in assuming I will need 3 of the cylinder hex wrenches to torque the cylinder properly?

2 of the 1/2" hex cylinder wrenches to properly torque the free-thru studs simultaneously and a single 3/8" hex cylinder wrench as those studs don't pass through to the other side?

Thanks
Jeremy

I think I will need the following three wrenches for the cylinder nuts style shown in the ebay link

https://www.aircraft-tool.com/shop/detail.aspx?id=6494-SET

plus

https://www.aircraft-tool.com/shop/detail.aspx?id=6494-2

https://www.ebay.com/itm/333727340621

 

[krhea]

Internal cylinder wrenchs

I bought a pair from ATS, made a backup with appropriate size hex welded on a flat bar. also had to grind on the head of mine a bit for better clearance. O320-D2A.

Keith Rhea
RV7
2022 donation

 

[lr172]

I am not aware of the need to torque both sides of a through stud at the same time; certainly not specified by Lycoming in the overhaul manual. This makes no sense on a narrow deck, as the stud is threaded into the left side of the case, unlike the wide deck that is not.

Larry

 

[lr172]

the free-thru studs simultaneously

On a narrow deck, they are not free. The stud has two sets of threads on one side. The inner threads lock the stud into the left side of the case. It is NOT free to move. Yes, they need to be torqued, but that is for stretch, not movement.

Larry

 

[Jermechanic]

Set of two ordered

thanks Keith and Larry for the info; i did read before that the case through bolts are NOT floating on a narrow deck. My 1/2” and 3/8” hex cylinder wrenches are in order