What happened here?

[Strode182]

I'm tearing my 360 down, and when I pulled the timing cover, I saw something had semi-gouged out the inside of it.





It obviously something from the cam, but what? If the cam walked that far, it would be the bolt hitting the cover. But that gouge mark is bigger than the cam bolt. It's about the size of the washer. It's smaller than the cam/distributor gear.

Plus, if you look at it, it walks from the RH passenger side, by the distributor, then towards the center. Which is backwards to me. If the cam broke, it would hit directly in front of it, then walk away from it maybe towards the distributor.

What happened here? This truck has never run for me. I bought it as a non-running project, and I'm just starting to work on it.

[cma]

could be a reference from the mill when they manufactired this part!

[grand_wag_85]

I've seen that on a couple of AMC's that I've torn down but never quite that bad. When you tore down the engine how did the timing chain look? Did the Jeep have the OEM camshaft gear(stamped aluminum with brown nylon teeth)?

Only explanation I can come up with is that the timing SEVERELY jumped and it was enough to knock the cam gear loose. That or at some point in the past the timing set was swapped but they didn't crank the bolt down and it came loose.

I'd also be interested to see how much front to rear(it's early in the AM and I forget the technical term for it) play there is in the cam.

[Strode182]

It's not stock. It has steel timing gears, and it's been apart before.

- The mark is the size of the washer.
- If it came "loose", the bolt would be the first thing to hit the cover, not the washer.

The only explanations I can think of is that the bolt broke exactly flush with the washer, then the head of the bolt somehow went down, not out, and the washer hit the cover.

Or

Somebody somehow put the engine together without the bolt, but with the washer, and started it up?

Dunno.....

[Heavy_Metal_Thunder_81]

I've seen timing covers with that wear but never seen it move around like that. Weird...

[Strode182]

Originally Posted by Heavy_Metal_Thunder_81

I've seen timing covers with that wear but never seen it move around like that. Weird...

When it wears like that, is the mark the size of the bolt head, or the washer?

That's what's baffling me......that and the direction it goes! LOL

[Heavy_Metal_Thunder_81]

Originally Posted by Strode182

When it wears like that, is the mark the size of the bolt head, or the washer?

That's what's baffling me......that and the direction it goes! LOL

That also has me stumped...

[grand_wag_85]

Come to think of it on the ones that I've torn down the mark was the size of the bolt, not the washer. I bet whatever happened there definitely made somebody's day.

[nc wagoneer]

Looks sorta how my ATV did, shop guy said in 15+ years it was the only time he'd ever seen a cylinder wall scored on ONE side!!! Guess that's what 6000 miles and 17 years of abuse without a rebuild will do for ya!!!

[Carnuck]

Looks like the cam gear bolt came out and the gear walked till it quit running (at high RPMS!)