Stripped Pressure Plate Bolt

Ok, so I over torqued a clutch pressure plate bolt and I think I stripped it in the flywheel. The bolt isn't coming out and I cant turn the bolt by hand. The other four bolts are seated very nice. So...can I leave it alone?

Reply to
Jo Baggs
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You can - but it's not a good idea since sooner than later it's going to do

2 things, both bad. First, you will warp the pressure plate as the pressure backs the stripped bolt out. Second, you WILL back that bolt out and the noise it makes when it goes flying will cause at least temporary panic even if it doesn't jam somewhere and take out something even more expensive.

To remove the sucker, use a sharp chisel or knife edge. Drive it under the head then try and back it out with a wrench while you pry with the other tool. Personal opinion: it's easier to just back the other bolts out then use the pressure plate to push the last one(the busted one) out as you crank with a wrench. Inspect that hole in the flywheel closely. If you bunged the threads in the hole you're in for new flywheel in all likelihood. If it's OK, use an appropriately sized tap to clean the threads, buy a new bolt and start over.

Reply to
Will Honea

Another removal technique that might work is to remove the bolts that can come out, then GENTLY pull on the plate as you turn the bolt that does not want to come out, hoping that a thread will catch and it will come out the rest of the way by itself. Obviously, you have to be sensitive to such things as bending the pressure plate.

When you get the bolt out, you will have to (at the very least) use a thread chaser to clean the threads, or use a tap to cut new threads. You can't make new threads with a chaser, but you can clean threads that have been damaged. A thread chaser kit will have chasers for bolts and holes. You may find that you will have to migrate to the next size larger bolt. This might present balance issues, I'm not sure. A thread chaser and a tap are a little bit different tool, but I suppose you could use a tap as a thread chaser if you have a tap already.

If balance is an issue -- you'd have to weight the bolts to see if the new larger bolt is significantly heavier than the original bolt -- then you would counterbalance the light bolts with an added washer. I think the mass and the relative small change in weight of a bolt shouldn't be a problem, but I'm not sure. Of course, you could tap all of the holes to the new size, and use five bolts that are all the same.

Reply to
Jeff Strickland

When Jeff and I agree, you got a problem. I suspect that you will be able to use the same threads once you clean them up. In most cases, the bolts are softer than the cast metal in the plate. If you use a tap - to me it's the original thread chaser anyway - be real care to get it straight and properly seated before cranking on it and use lots of lubricant in the hole. When done, clean out the hole with something like spray carb cleaner.

Another thought is to use a helicoil if the internal threads are buggered. I'm not sure if this is a good idea so check with a local machine shop before proceeding.

Might I suggest the purchase of a good torque wrench? Even my finely calibrated hands need some help with those smaller (less than 1/2 inch) bolts ;-)

Reply to
Will Honea

Thanks guys. I wont go into how it broke. Suffice to say it wasn't with a torque wrench.

Reply to
Jo Baggs

You weren't supposed to admit to that!! :)

Jo Baggs wrote:

Reply to
RoyJ

Heh! My epiphany was replacing the head gasket on a Mitsubishi pickup. The bolts are long suckers and not that big. The book specified one-time use only. After snapping a couple I found out that the spec puts them right on the tensile edge and heating will actually stretch them just a tad so that they won't take the spec'd torque once removed. They actually tell you to check the necking to make sure you have the new ones.

My biggest problem now is remember> You weren't supposed to admit to that!! :)

Reply to
Will Honea

Hi Joe, Take apart, it may be just the bolt that's stripped or you may HeliCoil:

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new threads into the wheel. Just thinkyou would feel if you cut his feet off!
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Reply to
L.W.(Bill) Hughes III

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