stripped oil pan bolt hole

2001 XJ, 4.0, AW4, NP231

Just replaced the rear main and while putting the oil pan back on I came across a bolt hole where the threads are stripped out. I can get the bolt to say in but there is no torque on it. Do you guys think I should drill and tap the hole for one of the larger size oil pan bolts? The hole that's stripped is one in the front. in the picture below it's the one in the right corner of the passenger side. What do you think I should do?

http://www.catskillhouse.us/blog/wp-content/uploads/2009/01/1997-jeep-cherokee-oil-pan.jpg

That doesn't really narrow it down.

I would be hesistant to start drilling that hole out. It depends on the amount of material available.

Have you tried a different bolt? Have you cleaned out the original threads with a tap?

I would do everything I could to make it work before I started drilling potentially crooked holes in the block.

Helicoil is the best. Otherwise just slather the gasket real good with The Right Stuff and call it done.

old_man said:

Helicoil is the best. Otherwise just slather the gasket real good with The Right Stuff and call it done.

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This. The best and correct way to repair your issue.

old_man said:

Helicoil is the best. Otherwise just slather the gasket real good with The Right Stuff and call it done.

Click to expand...

Never used Helicoil before but I've had others tell me I should do that rather than drill and tap. How does the Helicoil work?

Oh and I did try a different bolt, no luck

another option for low torq small bolts (if there are still some threads left) is to take a couple strands of wire and just put them in the hole a little deeper than the bolt goes. Then put the bolt in snugly with some locktite. The wire takes on the shape of what is left of the threads and makes the bolt tight. If you do this, do not overtighten the bolt. Let the wire and the locktite do the job.

Kevinma255 said:

another option for low torq small bolts (if there are still some threads left) is to take a couple strands of wire and just put them in the hole a little deeper than the bolt goes. Then put the bolt in snugly with some locktite. The wire takes on the shape of what is left of the threads and makes the bolt tight. If you do this, do not overtighten the bolt. Let the wire and the locktite do the job.

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If you're going to do this, I'd use relatively soft wire. And I'd still be nervous about making this a one-time use thing.

Helicoil is actually a trade name for a particular brand of helical wire insert used for thread repair. You drill out the existing munged up threads with a very particular size of drill bit, thread the hole with a specialized tap (no, it is *NOT* a standard tap,) and thread in a stainless coiled insert. Now you have brand new threads that the bolt threads can run on.

Kevinma255 said:

another option for low torq small bolts (if there are still some threads left) is to take a couple strands of wire and just put them in the hole a little deeper than the bolt goes. Then put the bolt in snugly with some locktite. The wire takes on the shape of what is left of the threads and makes the bolt tight. If you do this, do not overtighten the bolt. Let the wire and the locktite do the job.

Click to expand...

This works great and is simple... Use copper (speaker) wire multiple strands work best.

I have used helicoil several times, once on my diesel for one of the only 2 mounting bolts for the behemoth 40 lb starter, and the holes were in weak aluminum tranny case! Worked great! And does not require as big a hole as going to an oversized bolt IIRC.

little red cheroke said:

Never used Helicoil before but I've had others tell me I should do that rather than drill and tap. How does the Helicoil work?

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Your hardware store should have them as a kit.

You'll overdrill the hole (slightly,) use the tap provided, then insert the coiled wire insert into the hole. This gives you a thread repair that is the same size as what got screwed up in the first place (most of the screw holes are threaded 1/4"-20, with the four larger ones in the corners being 5/16"-18.)

YOU DO NOT NEED TO DRILL THROUGH TO USE A HELI-COIL - they'll work just fine in "blind" holes. Use a stop collar on your drill if necessary.

Take your time, be patient, and make sure your drill follows the hole properly. The tap will follow the drilled hole, if the hole is crooked, the tap will go in crooked.

Despite these warnings and such, you'll find a Heli-Coil insert is really quite simple to use, and instructions usually do come with the kit. I've used plenty of them over the years - back when I was building performance engines, using Heli-Coil inserts for main bearing cap screw holes and cylinder head screw holes was de rigeur, as well as any critical holes in aluminum castings (cylinder heads, intake manifolds, and the like.) I did it to prevent this sort of thing happening - the diamond-shaped CRES wire insert is several times stronger than a raw casting...

I am a Helicoil noob as I have only used them twice, but they worked well and were easy to use. I had a hard time finding them locally though, and ended up buying them from Amazon.