My thoughts exactly. I just didn't know if it would cause damage with the valve-train when it finally went, that was the whole purpose of this thread. I wanted to find out if it would cause catastrophic failure and destroy the top half of my engine.

 

If it ain't fixed, don't break it.

Or something like that.

 

Haha, reps for that one. Remember, I'm driving a Ford, not a Chev. I don't exactly have to baby it to make it last

 

When they start to go you will hear a bit of a knocking while the truck is at idle. My '86 had that knock and I put it off as something else even after dealing with a 2.5 Pontiac. Then the gears went LOL

 

I'm under the impression that there would be no warning before they go. It is two gears, so there wouldn't be much of a sign. I don't see how it would start knocking beforehand, when teeth go they just go. I would imagine it would be similar to losing teeth on a flywheel, not the end of the world but annoying as can be.

 

I recall reading somewhere here on this forum that if/when the timing gear breaks or gradually erodes, it can create small bits or chunks of phenolic pieces that can clog or otherwise impair normal oil flow. Which can then cause engine damage if not repaired.

 

Good point! I recall reading somewhere on here about a guy who's 300 lost oil pressure. Long story short - ended up being a pickup screen full of phenolic fibers and chunks. The gear was worn to heck, but still working.

 

Interesting.. That would be a horrible experience, especially after going to all the work of replacing the timing set..

 

Personal experiance with 2 engines with those gears as well as others in the Iron Duke world says they can knock. Mine lasted about a month that way then I geared down to stop at an intersection it shreded the teeth.

 

Do you have any explanation as to why they can knock? I'm not saying they can't, I just simply can't find a good reason why they might.

 

I suspect wear on the teeth as it seems to be common among almost any engine that has a phenolic cam gear. The Pontiac 2.5 just seems to be the one most noted as having the problem, alot shed teeth around 100k miles.

Sure wish I had a video of it when the truck was doing it.

 

Thanks for your input. I wish you had a video too, I don't have any experience with an engine that has timing gears instead of a chain or belt.

 

I have yet to check my current engine to see how it sounds but it was in a 4x4 and was kind of beat on so it will be interesting to see if there is any unusual sounds.

 

So what about the rumor that steel replacement gears can upset the knock sensor on the (I believe) '88-and-up engines? Steel seems like such a nice option, but not if the engine is gonna be running at half-power 'cause the computer is pulling timing.

Pat

 

What rumor is that? Someone else could probably fill you in on that better but I have never heard of anything.