O-360-A1A Crankshaft Oil Plug Replacement

RichWilson · #1 03-15-2006, 07:42 AM

I have an RV-8 with an O-360-A1A. I've flown behind a Sensenich FP prop for almost 300 hours and now am upgrading to a Hartzell CS prop.

I pierced my rear crankshaft oil plug to accomodate the FP prop and now I need to replace that plug with a solid one.

Has anybody done this without removing the crankshaft? If so, how did you do it? (The issue is removing the plug without damaging the oil thrower tube)

I'm thinking of designing a special tool to engage the plug and slowly pull it forward. I've got a few designs in mind--has anybody got a tool for this operation?

Thanks in advance for all the help,

Rich
N707RW (photos at www.wilson235.homestead.com)

rv6rick · #2 03-15-2006, 08:04 AM

You go down to your local auto body shop and pick up their 'dent puller' (or make your own. Screw it into your pierced hole (or make a new one of the proper size) and screw the dent puller into the hole. One rearward slam of the weight on the puller will be enough to jar the plug loose. Don't sweat the crossover tube as you'll be to the side of it.

Also, you'll need a tool that will 'straddle' the crossover tube when inserting the new rear plug in your crank. You can make one (like I did) or borrow one from an engine shop. Don't try to secure the new plug with a screw driver or some other foolish tool......use a tool that will push the plug in uniformly and will straddle the crossover tube.

Not sure where you are but you can borrow my tool if needed.

You are going to LOVE your new prop!

Rick Gray in Ohio at the Buffalo Farm - RV6 Sold, RV8 finished, RV4 prepping for paint, RV10 and F1 Rocket under construction

RichWilson · #3 03-15-2006, 01:45 PM

Thanks, Rick. I'll do exactly that. The thought of using a dent puller had actually crossed my mind, but I just wasn't sure I could do it without damaging that oil tube.

Got a photo or some guidance on how you built your straddle tool? I'd be happy to copy your design.

I'm sure lookin' forward to that prop.

Rich

Squeak · #4 01-23-2007, 06:16 AM

Need to get a hole or remove the back plug so I can go from C/S prop to F/P. Still do not know the reason for this but Lycoming said needs to be done. What did you use to pierce the hole in the plug? I have a new plug and they are about 1/8? thick steel plug and looks like it would be kind of hard to piece a hole into it.
Thanks for any help,
Squeak

mrreddick · #5 01-23-2007, 06:26 AM

Quote:

Originally Posted by Squeak

Need to get a hole or remove the back plug so I can go from C/S prop to F/P. Still do not know the reason for this but Lycoming said needs to be done. What did you use to pierce the hole in the plug? I have a new plug and they are about 1/8? thick steel plug and looks like it would be kind of hard to piece a hole into it.
Thanks for any help,
Squeak

Squeak,

Lycoming is right! On a constant speed prop, that chamber feeds oil to your prop under pressure. If you have no plug, or have a hole in the crankcase plug as mine did, you wouldn't get pressure to change the pitch.

For a fixed pitch prop you either pierce the plug or remove it (not really that hard to do).

rv6rick · #6 01-23-2007, 06:26 AM

The hole need to be there to relieve any pressure in the crank.....this will prevent the front plug from popping out if pressure should build.

If your 'new' plug is out....the obvious is to drill it. If it's installed then a nice sharp punch will do the trick. Best to punch well off center on the 'wide' side of the sludge tube. After that don't forget that you'll need to intall a new front plug.

Squeak · #7 01-23-2007, 06:36 AM

I was afraid to drill a hole in the plug because of contamination from the shavings. Thought that it would have to be pierced with a sharp punch but the new plug looks to thick to pierce with a punch so are you saying Rick to drill a hole in the plug for the dent puller.
Thanks,
Squeak

rv6rick · #8 01-23-2007, 07:04 AM

OK...let me start over as I'm not sure where you are with the process:

-if you are changing from C/S to fixed pitch you will need to have a REAR plug that has a hole in it or, NO rear plug at all. I'll mention that some rear plugs have a 1/8" npt inserted that can be removed leaving a hole for you.

-IF you have removed your rear plug then you can just leave it out and install a NEW FRONT plug ,then install your FIXED PITCH prop.....you are done.

-IF you have NOT removed your rear plug you can a) remove it by piercing it with a punch and using a dent puller and leave the plug out or b) pierce it with the punch and leave it in place. 'If' you damage the plug when you attempt to pierce it (not likely but it can happen) then you'll be removing it anyway since you don't want it coming loose and slopping around in there.

-If being removed, once pulled from its seat with the dent puller....the plug can be laid down and will clear the off center sludge tube and be removed with some long pliers or whatever.

-IF you are installing a new rear plug for a FIXED PITCH prop....then you could simply use a drill to put a hole in it before installation. You are correct in that you wouldnt' want to drill into an installed plug due to shavings getting inside of the crankcase.

-IF you are installing a new rear plug for a C/S application then there will be NO HOLE in the plug as you need the oil pressure to operate the prop.

-If you are considering going back to C/S one day then you might want to install a rear plug that has a provision for the 1/8" npt plug, but leave the pipe plug out for the fixed pitch application. That way a future owner would only have to put in the pipe plug to change over to C/S.

Again, no need to install a rear plug if going with a fixed pitch.....but DO NOT forget to install the front plug, and IF you DO have rear plug it needs a hole in it due to explanation given in my previous post.

Hope this helps.

Squeak · #9 01-23-2007, 08:25 AM

Rick, Thanks for explaining the procedure on the crankshaft plugs it really helped. Bought a 0-360 A1A that was using a C/S Prop and I am installing a Catto Prop. The rear plug did not have the 1/8" pipe plug so I will punch a hole in and try to remove it with the dent puller. Have a new plug for the front that I will install. I just did not know the reason for the hole in the back plug but now I understand.
Thnak you,
Squeak

wv4i · #10 01-23-2007, 08:29 AM

There are Lycoming service bulletins and at least one AD that are relevant to what the thread starter is proposing to do, have some of the answers he may be looking for, etc., except how to get to/at the rear plug without disassembly.

A word to the wise is that if the front crank plug (installed on a FP application) comes loose, or develops a leak, in flight, you will soon have oil all over your windshield. Do be prepared to land looking out the side windows for reference if this happens. If such event advances to a low/no engine oil situation, you are now looking at an emergency landing, possibly off airport, looking out the side windows, not to mention engine damage.