Stripped Oil pan mount threads

Guerillastyle

NAXJA Forum User
Location
SF
My Jeep, '88 XJ, has been leaking oil ever since I changed the oil pump unit due to stripped threads which hold the oil pan to the bottom of the engine block.
I am sick of the leaking oil and the inefficient delivery system. Overall there are about 5 bolts that are stripped, the 2 upfront underneath the crankshaft being the main culprit of the leak. Again will be taking matters into my own hands, and my options to mend the stripped threads have dwindled down to:

1. Helicoils; Which I have already ruled out due to a prior attempt at fixing this situation previously with helicoils. Needless to say I failed and definitely screwed myself further.

2. Time-Serts; I feel this is the correct remedy due to their beefy build and the possible ability for them to hold the weight of the pan and oil when torqued down.

3. Melt aluminum back into the block some how and re-tap.

I would greatly appreciate if anyone could weigh in on these options and quite possibly their personal experiences with any mentioned or unmentioned thread repair options. :cheers:
 
Couldn't you just redrill the holes a size larger and tap for larger bolts? Put some grease on your drill bit to collect metal shavings and drill through the pan at the same time. That way you wouldn't need to drop the pan. Just remember what holes the larger bolts go in if you ever need to drop it again.
 
Couldn't you just redrill the holes a size larger and tap for larger bolts? Put some grease on your drill bit to collect metal shavings and drill through the pan at the same time. That way you wouldn't need to drop the pan. Just remember what holes the larger bolts go in if you ever need to drop it again.

How would drilling with the pan effect the gasket? Might be a small enough of a difference in bolt hole size that it won't even touch the gasket.
 
Heli-coils should work fine. It isn't clear to me why the Time-serts would be superior in this application. Drilling/tapping the block to a larger size is another option. The oil pan bolts generally fit loosely through the gasket - but they aren't THAT loose so you'd to watch if you're drilling the gasket. A couple of the bolts up front go through the timing cover. There you're dealing with aluminum, not cast. Torque spec is 84 in-lb on the smaller 1/4-20 bolts and 132 in-lb for the larger 5/16-18 bolts.
 
How would drilling with the pan effect the gasket? Might be a small enough of a difference in bolt hole size that it won't even touch the gasket.

I was referring to the larger bolts fitting in the holes in the oil pan. If you leave the pan on you know the holes will line up correctly. I'm guessing at what you're asking about. But that's why I suggested leaving the pan installed. :cheers:
 
If the holes are in bad shape and helicoils won't work my vote is to drill them out and rethread the holes for the next size. You may have to use Allen head screws to clear the edge of the pan, but any hardware store will carry what you want. Going to a 5/16 shouldnt hurt the gasket. There will be enough gasket material to seal the pan. A torque wrench is a must. An even torque around the pan will aid in sealing. You also should check the sealing edge of the pan and make sure it's flat. Any humps or divits will make it difficult,if not impossible to seal the pan
 
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