ROCKER BOX: Stripped Internal Threads

[Jack Klarich]

Well there's an idea I hadn't thought of!! Good one, Bubbie!

Trying to figure something out, though...

First, the Rocker Cover (top plate) is held on by four bolts to the bottom plate. One of these four is now stripped out (the hole, not the bolt). What I am trying to ascertain is this: If I took the bottom plate off, could I look through the mounting bolt hole, or is it only threaded partially through the plate.
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The reason I ask is that I don't want to screw something further down into the hole and have it obstruct moving parts beneath the bottom plate. Does anyone know the answer to this question? I know my depth gauge is bottoming-out, but WHAT is it bottoming-out on - the bottom of the hole, or something in the head?

That is a blind hole meaning it ends, the lower rocker cover mounts to the head with bigger cap screws. IMO the bedt way is to replace the lower cover, I do not think there is enough material to drill out and install a time sert, however this is not a critical torque so you may use the Permatex thread repair here and call it a day JMO

 

[HDDon]

There are two way to figure out if the hole is through or blind. One is to measure with a depth gauge and then add up the stack. The other is to take it apart and look. If you measure it will still not tell you is the hole is threaded to the bottom. I think it is a 1/4-20 bolt so if you have a long piece of threaded rod or a long enough bolt screw it into what thread is left and measure what is sticking out.

 

[Mongo44]

That is a blind hole meaning it ends, the lower rocker cover mounts to the head with bigger cap screws. IMO the bedt way is to replace the lower cover, I do not think there is enough material to drill out and install a time sert, however this is not a critical torque so you may use the Permatex thread repair here and call it a day JMO

Jack, I sincerely thank you. Ha! Been looking for an answer to this question for quite a long time. Will check into the Permatex.

I plan to do some more involved work on the bike - changing the inner cam bearing - so I'd like to be able to ride the bike while I wait for parts.

There are two way to figure out if the hole is through or blind. One is to measure with a depth gauge and then add up the stack. The other is to take it apart and look. If you measure it will still not tell you is the hole is threaded to the bottom. I think it is a 1/4-20 bolt so if you have a long piece of threaded rod or a long enough bolt screw it into what thread is left and measure what is sticking out.

I think I got the answer above. Yes, the bolt is a 1/4"x20. Thanks so much, Don!

Thank you both. This has been extremely trying just to get to this point. Now I have a big smile on my face!

 

[BUBBIE]

well there's an idea i hadn't thought of!! Good one, bubbie!

Trying to figure something out, though...

First, the rocker cover (top plate) is held on by four bolts to the bottom plate. One of these four is now stripped out (the hole, not the bolt). What i am trying to ascertain is this: If i took the bottom plate off, could i look through the mounting bolt hole, or is it only threaded partially through the plate.

The reason i ask is that i don't want to screw something further down into the hole and have it obstruct moving parts beneath the bottom plate. Does anyone know the answer to this question? I know my depth gauge is bottoming-out, but what is it bottoming-out on - the bottom of the hole, or something in the head?

You should be able to figure that out by the depth and compare it to the outside.

I don't think the hole goes Thru, just a threaded hole that ends at the point where you see on your gauge.

Lot of problems happen when the bolts get Mixed up and an 1/8 to a 1/4 inch bolt is torqued to tighten and bottoms out first. Takiing All the threads with it.

Different than your pulling out most of them using the oil pressure gauge braacket as a shortened depth adjustor.

Have you tried to measure that amount of the threaded hole so you Might be able to use a LITTLE longer bolt? 1/8 max. Compare that depth to the right bolt used to tighten and remember the bottom of the hole is tapered not flat and the threads usually run out before bottom. IF you use a smiggy longer bolt. Torque using the Least amount shown in your book...

IF it threads in by hand and stops before it is touching the cover, it IS too long. IF you torque it down and it is too long, it will pull out the few threads you haved left.

It may be possible and I know of Nothing in the way but the bottom of the hole. NO, not open to the head that I remember. HD usually has them Stop not go thru.

signed....BUBBIE