My 1985 Ford F-150 300 six just died while hauling a load of wood. Rpm's were high at the time. Rebuilt the carb, put in a new distributor (pin was broke) and it still won't start unless I pull the distributor and re-install it 180 degrees off of dead top center (TDC). Don't ask me how I figured that out. It starts and runs but not very well and makes noise (clanging like some things loose) I'm thinking some timing gears may be stripped. Has anyone dealt with this? Any thoughts would be great.

I have also discovered that TDC is opposite the timing mark on the crank. It's about 180 degrees out.

 

Hi Remodeler, sorry I missed this post. Have you had any new discoveries on your engine?

When you removed the bad distributor, did everything come out with it? (Gear, etc) Was there any damage to the teeth on the old distributor? Or just a sheered pin?

It's possible you shredded the timing gears. On '84+ engines, they're made of phenolic fiber instead of metal to keep the sound down. They'll last a long time, but once they go, *poof*. If they're bad, they'll make quite a knocking sound. Normally, though, they won't run at all.

The way to diagnose the timing gears is to drain and pull the radiator, get a balancer puller and pull the harmonic balancer, and then take off the timing cover. If they're indeed damaged/destroyed, you'll need to pull them off and install new ones, as well as remove the oil pan and clean all the pieces of timing gear teeth out or it'll clog your oil pickup.

Before you look into that, though, it's possible your harmonic balancer has simply slipped and the timing mark is no longer pointing where it should. I've had this happen. The balancer is two pieces and they're held together with vulcanized rubber. Over time, the rubber will lose its grip and the outer ring will start to slip. At this point, the timing mark is useless.

To check this, bring the #1 piston to TDC and then look at the timing mark. It should be pointing right at 0 on the timing marks. If not, it's more than likely slipped.

If it needs replacement, you'll need to follow the above steps as well (aside from removing the timing cover, although you might as well while you're there.)

 

Thank you for responding AbandonedBronco.

I have not done anything else to my truck yet.

The whole distributor came out with the oil pump rod and there was no other damage that I could see besides the gear just spinning free (pin sheared).

I have 226,000 miles on the engine so, this wouldn't surprise me if the timing gears were stripped or damaged.

I have found TDC a couple of times and the timing mark is on the opposite side of the balancer which made me realize something wasn't right.

I'm still able to start the truck if I re-install the distributor 180 degrees out but it doesn't run well at all. I hope I haven't done more damage by running it. I haven't been driving it but, just starting it to move it to a more suitable spot to work on it.

You have pretty much confirmed I need to take the front apart which I will be doing tomorrow (Sun). Fortunately I don't need this truck for daily needs so, I will have some time to take my time on it since I've never done this before.

Thank you again for your help.

 

Some comfort is that the 300 is a non-interference engine, so as far as that goes (valves hitting the piston, etc.), put your mind at ease.

Hopefully you'll be able to trace down the issue quickly. Keep us posted on what you find.

 

I have finally had a chance to take the timing cover off. The timing gears visually look O.K. but the timing marks are almost 180 degrees off. How can that happen? Can they skip teeth that much without breaking teeth? May be I should replace the timing gears anyway while I have the cover off.

 

Someone must've taken the cam out at some point, or put new gears on, and either didn't know or couldn't be bothered with installing them in the correct direction. There's virtually no way I can think of that a gear to gear setup can skip teeth without some form of damage taking place.

If you have the phenolic fiber cam gear, it may be a good time to replace it with a good metal setup. But, if the gears look to be in nice condition, you can probably just save yourself some time and money and put them back in correctly with the two alignment dots touching.

 

Is the keyway on the cam gear and cam aligned properly?

 

Thank you AbandonedBronco for your input and advice. I don't know what happened with the cam or if I just wasn't reading the TDC right. Anyhow, I finally got a chance to change the gears and put it all back together. The truck runs better than it has in years except for one thing. I now have a banging sound or a wap wap wap or clacking sound coming from the motor. I can't tell if it's coming from the distributor area or the front where I replaced the gears. I do know that when I listen from the passenger side opposite the distributor I don't hear it as loud. I'll pull the distributor this weekend since I ran out of time last weekend and hope it's something small. However now I fear that I have a bent pushrod or bent cam. I was banging on the cam gear pretty good when trying to remove the fiber gear since I busted the gear with the puller. So, I had to get it off by other means I.E. cutting with a grinder and banging.

Tiap: the key way was fine.

 

Did you install the spacer and get the correct end play for the cam?
If it moves too much, it will bang.

 

Is it a banging sound? Or kind of a growling noise?
I had the bolts that hold the cam plate down come loose, and the cam could move back and forth about a 1/4". It would growl when the cam moved up against the timing cover.

 

Tiap: Did not install a spacer. Didn't know about one nor did I have one.

Abandoned Bronco: I remember double checking the cam plate bolts and they were tight. And it is definitely a banging noise.

 

I had a similar noise that sounded like rods knocking, only when hot not cold. It also ran poorly.
Pull the dist out and look down at the camshaft while someone bumps the engine over with the starter in short bursts. If you see the cam walk back and forth, then that's your problem. Without the spacer to limit movement, that will happen.

Read both these threads, the loose gear won't apply to you.

https://www.ford-trucks.com/forums/1...-troubles.html

https://www.ford-trucks.com/forums/1...-question.html

 

Thank you Tiap. I will try that next. The truck actually runs great. At least for the 30 seconds I ran it. Seemed to have plenty of power.

Is it possible I put the cam gear on to far forcing the cam to far forward? I used a bolt and washer to seat it. If I remember correctly I got the cam shaft to come flush with the gear housing almost proud.

Thank you for your input. You probably won't hear from me for a while as I have a brother coming into town for the week end. I may be able to enlist him to help me check the cam. We'll see.

 

Doubt you have the cam too far forward.
Most of the gears end up back about 1/16" from flush (stub sticking out) so if it's flush there's a possibility of you having that much slop.

So check for the cam movement and go from there for the noise.