2002 Durango SLT 2WD
4.7L Engine

I wrung off the bottom bolt on the T-stat housing while replacing thermostat & water pump. I tried drilling a hole in the bolt & using an extractor but the hole I drilled in the broken bolt ended up going off-center and the extractor catches on the engine block at the edge of the threads.

Though it's hard to see due to it's location, it appears that the bolt is broken off just inside the threaded hole, leaving just a tad bit of a recess that could be used to drill the bolt & bolt-hole threads out for a helicoil. I've never used/installed a helicoil before but many moons ago I used to be a machinist and I'm mechanically inclined (except for this bonehead bolt-wringing incident).

Anyone have any advice, tips and/or tricks to share with me?

Thanks for your time!

Have a good one!
HH

 

I think helicoils at great. I've used then a few times. I even used one on my wife's VW motor mount bracket... Still holding torque nearly a year later. They at not too difficult to install.

 

Same problem happened to mine, and i tried what you did. didnt work took it to some shop and 100$ later they had it fixed.

 

Thanks for the replies, folks!

Due to lack of time I just got this job finished yesterday (Saturday). As mentioned in my first post, the hole I drilled into the broken bolt ended up drifting off-center, making the hole halfway in the bolt & halfway into what I first thought was the engine block, but fortunately was the timing chain cover, instead.

On my 2002 4.7L, the bottom bolt of the thermostat housing hangs below the rest of the engine. The thermostat housing has 2 guide bushings that protrude into the timing chain cover & helps align the bolts. I measured the diameter of the bushings with a micrometer and I just so happened to have a drill bit that was aproximately .020 inch smaller. The drill bit I used was a 13/32 inch. I drilled a hole all the way through and ran a bolt through it & placed a lock-washer & nut on it. I had to bore the inside of the bottom bushing out a few thousands of an inch in order to get a 5/16 inch bolt through it.

Due to limited space with the radiator still on the Durango I had to use a dremel tool to cut the 13/32 drill bit down to about two inches long and I also had to use a cordless drill because it was shorter than any of my corded drills were.

I took it for a test drive last night & it did fine. No leaks, yet, at least. I took the day off today, didn't even put away my tools, yet. My wife drove it to the store & back this afternoon with no problems. A lil' bit later in the day she started backing out of the driveway to go somewhere else & all of the sudden the passenger side tie rod end broke. Thank God it broke in the driveway and not while she was drivin' down the road at 65mph with my kids in the vehicle.

Guess what I'll be doin' tomorrow? Ha! Ha!

Ya'll take care!
HH

 

Hello HH,
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On the lower thermostat housing. The NEW hole that you drilled was it through the original lower hole with the broken bolt that started going off center OR did you just create a NEW hole in the bottom of the thermostat housing and bore it out a little for the guide????
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Thanks for the very helpful article
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I know the post is 5 years old but the same problem happened to me yesterday.
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If you could email me that would be GREAT.. coralparadisemail@gmail.com
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Thanks Kenny T.