2001 Chevy Venture rocher arm ajustment

Tiny
SANCHEZ7
  • MEMBER
  • 2001 CHEVROLET VENTURE
Engine Mechanical problem
2001 Chevy Venture 6 cyl Front Wheel Drive Automatic

I torque valve reocker arm bolt 124 pounds and I stripped the thread inside the heads. Can I get it retreaded or do I need new heads, am I doing this right if not can you explain?
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Thursday, July 1st, 2010 AT 2:26 PM

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Tiny
CARADIODOC
  • EXPERT
Hi sanchez7. Welcome to the forum. 124 foot pounds is WAY too high for rocker arm nuts and bolts. That's even more then most head bolts call for. You must have looked up the wrong application, or they specified 124 INCH pounds.

For a stripped threaded hole in the head, take one of the other bolts to your favorite auto parts store and ask for a Heli-Coil repair kit for that size bolt. It will include the correct size drill bit, the correct size tap, the inserts, and the inserting tool.

Before you start, use a piece of wire to measure the depth of the hole. After drilling out the hole, use rags and compressed air to remove the chips, then use a magnet to be sure they're all removed. Do the same thing after tapping the hole. Measure the depth of the hole again to be sure no chips are in the bottom that the bolt can butt up against. Install one of the other bolts with its rocker arm, then count the exact number of turns it takes to remove it. Put that bolt back in the same number of turns without the rocker arm. Use a small ruler to measure the distance from the bottom of the bolt head to the surface of the cylinder head. The bolt you're repairing must go in at least that far too. Compare the bolt length you just just measured to the depth of the hole you're repairing. You'll need at least 1/8" more depth for the repaired hole. Drill it a little bit deeper before tapping it if you have to.

Compare the depth of the hole to the length of the insert. It should be at least 1/4" deeper than the insert because the tap is tapered and won't reach all the way to the bottom. The threads you cut with the tap have to be at least as deep as the insert.

When you wind the insert in, you won't be able to remove it again so be sure you're ready to complete the repair. Also be sure when you're done, the top of the insert must not be sticking up above the hole or it will hold the rocker arm up a little. When you run the bolt all the way in the first time, it will break the tab off that hooked on the inserting tool. That tab could stay in the bottom of the hole which is why the hole has to be at least 1/8" deeper than the bolt goes in. You might be able to retrieve the tab with a stick with a little grease on the end, but don't count on it. Chances are it's there for good unless you tip the engine over!

The center of the the insert is the same thread size and pitch as the original bolt and will be just as strong as the original hole.

Caradiodoc
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Thursday, July 1st, 2010 AT 3:11 PM
Tiny
SANCHEZ7
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How do I tighten the rocker arm or what is the right adjustment specs?
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Thursday, July 1st, 2010 AT 3:41 PM
Tiny
CARADIODOC
  • EXPERT
I don't have a service manual for your vehicle but I can offer some suggestions. There are a number of web sites related to engine rebuilding and repair that have torque specs. Also, to get you in the ball park, a lot of books, text books in particular, list maximum torque values according to bolt size. If I had to guess from past experience, I would suggest 15 to 20 foot pounds would be typical for a rocker arm bolt or stud, but look it up to be sure.

I'm in the middle of loading up a bunch of service manuals to take to a swap meet. I'll look for the spec and post it if I find something.

Caradiodoc
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Thursday, July 1st, 2010 AT 3:56 PM

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