Exhaust cam gear service bolt 1fzfe (1 Viewer)

[ttmon]

Pulling the head today on a '94 1fzfe and went to put the service bolt in the exhaust cam gear. There is, what appears to be, a dowel pin in the hole (left hole in the picture). It's far enough in that it doesn't contact the outer half the cam gear. Nothing about it looks like a sheared off bolt. I pulled the cam as is - the gear didn't move. Any ideas what's going on here?

 

[w460traitor]

If anyone knows, @OTRAMM does!

 

[OTRAMM]

Sure looks like someone broke something off in there. That's the hole that the service bolt should be in.

 

[RiverCityDave]

Yessireebob. I'm no OTRAMM (I wouldn't even be working on my truck without OTRAMM's videos,) but I agree totally. I'd lay money what happened was they put too long of a bolt in there to lock it and then when they rotated the cams with the flats they broke it off on the head.

 

[ttmon]

Yessireebob. I'm no OTRAMM (I wouldn't even be working on my truck without OTRAMM's videos,) but I agree totally. I'd lay money what happened was they put too long of a bolt in there to lock it and then when they rotated the cams with the flats they broke it off on the head.

I would agree but it's about 3/8" inside the gear. If it sheared off I would expect it to be about flush with the outside of the gear. The face of it is also perfectly smooth and round. A dull shear would have deformed the bolt at least a little bit. I'm going to make a jig to lock the gear in place and drill whatever it is out from the cam side.

Is the threaded part of the hole threaded all the way through? If not maybe a long bolt was put in and bottomed out and snapped.

 

[Rifleman]

Well if that service bolt hole is in fact a blind hole, and if someone bottomed out a bolt, and snapped it off, i can tell you it's going to be a little bit of a pain in the butt to remove,

But if that is in fact a dowel pin that someone has stuck in a blind hole, it will be a EVEN BIGGER pain in the butt to remove,

Unlike broken bolts which are soft and drill able, dowel pins are SUPER HARD (At least 60 on the Rockwell C scale) so you'll need to take it to a machine shop that has a sinker EDM machine and have it brunt out

 

[ppc]

Unlike broken bolts which are soft and drill able, dowel pins are SUPER HARD (At least 60 on the Rockwell C scale) so you'll need to take it to a machine shop that has a sinker EDM machine and have it brunt out

But a dowel pin without threads should easily tap out with a punch or other tool.

 

[ttmon]

But a dowel pin without threads should easily tap out with a punch or other tool.

What I'm calling a dowel pin, for lack of better term, is a short rod threaded on one end. Maybe I should call it a stud. Exactly like what's in the hole to the right in the picture.

 

[Rifleman]

But a dowel pin without threads should easily tap out with a punch or other tool.

Not if it's in fact in a blind hole, now if it's in a through hole, then ya, a hammer and punch would work to remove that dowel

 

[WarDamnEagle]

So just put a bolt extractor on it and remove it.

 

[RiverCityDave]

I would agree but it's about 3/8" inside the gear. If it sheared off I would expect it to be about flush with the outside of the gear. The face of it is also perfectly smooth and round. A dull shear would have deformed the bolt at least a little bit. I'm going to make a jig to lock the gear in place and drill whatever it is out from the cam side.

Is the threaded part of the hole threaded all the way through? If not maybe a long bolt was put in and bottomed out and snapped.

Yeah, but with those, the "front half" is larger in diameter, giving the bolt room to deform before it breaks. I thought about people doing that the last time I worked on mine. I told someone to use "whatever would fit," then I rethought it and said to use something that would clear the front of the head for just that reason.

In any case, you should be able to get it out, one way or another.