Universal 16hp Oil Leak-need Advise

[mark stevens]

On the bottom of my timing chain cover there are 2 almn. press in tapered plugs originally installed to close off holes used to gain access to internal adjustments. One of these plugs has semi-rotted out and now I have a fairly profuse oil leak when the engine is running. I tried filling with 5200, liquid metal ect. and all failed. My problem is that there is only 5" clearance from bottom of cover to bilge. Rather than remove the engine and pull foward to repair - I have used right angle drill attachment and drilled the 3/8 plug out completly using a mirror.(Now I know how my dentists feels)My question is I am not sure what type of tap to use now that I have the hole. Should I use a 1/2 pipe thread tappered tap? and a tapered course thread bolt?

 

[david lewis]

Sealing Hole

Since your hole goes thru you obviously need to seal it. You can try a pipe tap but you will need a pipe plug and teflon tape. It should handle the heat since the oil only gets to probably 180 degrees or so. A better method is to chamfer the hole and counterbore it and then use a straight thread plug with an o-seal. The o-seal seats in the counterbore and compresses against the face of the plug. This is a standard aerospace fitting and should be readily available. Another option is a sealing washer which comes with rubber molded on the ID of the washer and when the screw is tightened the rubber compresses against the housing and the screw head sealing both sides from leakage. This last item might be your best bet with limited access. A straight thread tap will do the trick. Use grease on the tap and reverse rotation often, unscrew it frequently. The grease will lubricate the tap but even better will trap the chips. Since you drilled the hole you might have chips in your oil pan, Make sure you change your oil a few times after the repair.Dave