I'd do what the cam manufacturer says....

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There is a specific way to install the gear of the correct material. I think I found the instructions on Ford Racing's website, where they list the distributor gear. Something worth considering is the galley plug. Many of us drill that plug that's almost directly behind the gear with a 1/16" bit, which helps spray a little oil on the gear area. I don't know if it really makes any difference--some say it does, others not so much.

Also worth mentioning is that if the gear isn't correct for the camshaft, it can wear the distributor gear OR it can wear the cam's drive gear--which I have seen happen too. I've seen the teeth completely gone off of the camshaft in a 351w that a guy up the road built with a hydraulic roller cam and a cast iron distributor gear.

 

If you have been through more than one gear, it's time to look at basics.
I assume the MSD distributor is new? Edelbrock recommended a melanized iron gear. Did you buy them from MSD or somewhere else?
Did you build the engine? Did it run with a different distributor before? Do you still have the old distributor?

Yeah, lots of questions.

 

If you have been through more than one gear, it's time to look at basics.

I assume the MSD distributor is new? Edelbrock recommended a melanized iron gear. Did you buy them from MSD or somewhere else?

Did you build the engine? Did it run with a different distributor before? Do you still have the old distributor?



Yeah, lots of questions.

Yes it's a new distributor, I bought it and the gear from msd, I built the engine from the bare block so it didn't have a distributor before.

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I have purchased new MSD distributors that have the gear mounted out of spec. Check that the gear is in the right spot. Ive used melonized gear and it wore out and failed at 900 miles. I went to a poly gear and it has 5000 miles now with very little wear. Maybe a poly gear or a bronze gear would work. Also, I assume you are using the break in lube? I also agree on drilling the oil galley plug. I did that and it sprays oil directly on the shaft and gear. And BTW, Lunati recommended I use that coAted meLonized gear and it failed on me. So I wouldn't take what the manufacturer says as gospel. I had to pull the motor and get the 7 teeth out of the pan that broke off from their expert advice. Good luck. So many problems from that stupid tiny gear.

 

Dang sounds like a nightmare. What kind of cam did you have? I am using the recommended gear but it just doesn't seem right.

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Check the distributor setup carefully and use the cam manufacturers recommended gear.

I went through 5 billet Fast distributors and they were all junk. The shafts were out of spec on diameter. The gear would just slide right on and off with no pressure.

Not only that, they had the original gear at the wrong height!

The gear should have slight interference to the shaft. It should have to press on and off with some modest pressure. The pin then just holds it in place and is in shear. If you have clearance the gear will wobble and rock and cause abnormal wear or even break pins.

The gear face has to rest on the block shelf without being held up or forced down. It has to float there on the oil film, with only the gear angle and torque holding it down. You check this by checking the pull up on the shaft for some vertical free play when the distributor is bolted and seated down. This play is imperative.

If you use the proper gear (as speced by the cam manufacturer) and still have wear you can feel in a short time, you might have a screwed up cam. If you do stick a bronze gear on it, change your oil more frequently, and keep and eye on it. Or change the cam.

 

You may want to look at these instructions..ford racing distributor gear install..

 

I think the gear being off is a big problem. I believe for a small block Ford it is ~4.000". Definitely check that.

 

Also; look down the hole at the gear teeth on the cam. Are they damaged?

 

Are you just re-using the hole thats already drilled in the shaft for the new gear? If so thats rarely in the correct spot. You have to turn the gear 90 degrees to the existing hole, set depth and drill a new 1/8 inch hole for the roll pin. Its rarely in the correct spot because the pre drilled hole in the new gear is not in the same location as the old gear hole

 

so having a junk used msd distributor is a good thing to have laying around I guess

 

Who assembled your engine?
A few years ago I had a local shop assemble a short block for me. At about the 500 mile mark I was doing an oil change and found piece of a spiral lock in the catch basin. So out comes the engine.
While taking the engine apart, I found my distributor gear was demolished.
Digging deeper, I found that the jackass that put the new crank gear evidently needed some minor massaging in the slot for the crank key, but instead he grabbed a big hammer and a chisel and hammered the crank gear into the crank. You could see the marks.
He also did not get it deep enough, and the chain was pulling the cam forward (you could see the angle from the side), and both the distributor gear AND my 500 mile XE270HR was ruined.
You need to pull the timing cover and lay eyes on what is going on.

 

Wow! That sucks! It's stories like this that can make an enthusiast give up altogether.

 

Have you tried a stock distributor?

 

I'd also put camshaft endplay on the to check list.

 

Alright guys so I measure the depth and the machine shop did not set it at the correct depth. I'm gonna punch out the pin, set the depth and do myself. Hopefully this fixes the problem. I'll let you guys know.

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Alright guys so I measure the depth and the machine shop did not set it at the correct depth. I'm gonna punch out the pin, set the depth and do myself. Hopefully this fixes the problem. I'll let you guys know.

...

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Pattern does seem to indicate in needs to be that 0.050" deeper. That's pretty far off.

While we're at it, let me nose in here - new cam, new disty in my new setup, normal break-in wear?

 

Did you take your measurement with the shaft pulled out? What kind of oil pump driveshaft you running? Some MSD distributors will will not let the distributor shaft drop all the way in the block with a heavy duty oil pump shaft. Quick check is drop it in. Should be able to move the dist shaft up and down slightly. Then hold the shaft all the way down and see if the housing will move up and down a little. If so your good. I had one (MSD dist) ready to drop in my engine I just finished up and it bound up like this so I removed the new gear, installed it on a extra factory dist and it's been good to go. Did you do the oil galley plug oiling mod while you had it tore down? I did and have had no problems with my Lunati Voodoo cam gear.

 

I have an oem replacement pump and shaft. That part seems ok. I don't not have the hold drilled though.

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When I primed my pump, the way I could tell if it was primed was the drive hex gets covered with oil, so I'm not sure what the mod does.

 

Are you running a high volume pump, they can contribute to accelerated gear wear?

 

It's an oem replacement

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The wear difference between a HV pump and a standard is unnoticeable.
The primary load on the pump shaft is determined by head pressure at the pump outlet.

The proper way to set a gear for height is to check the actual "pull" clearance on the distributor shaft. You really never want to set off measurements to the distributor body unless you use some sort of fixture or you know how to get a good measurement.

When we made OEM distributors we used a fixture. It located the gear and held the drill guide, but it was not aftermarket off size crap. I measured about 5 FAST billet distributors and they were all sized wrong. I stayed with OEM Ford.

1.) The gear has to press on to the shaft with slight interference. It should not "fall" on or off, because that will let it wobble a tiny bit.

2.) The distributor should have up and down shaft movement, but virtually no side play clearance.

3.) The machined gear end face has to rest on the block shelf. It rides there on an oil film. The tooth angle pulls it down against the shelf. This is what locates the gear height.

4.) The gear should rest on the shelf with several thousandths "push up" on the shaft, you want the block shelf to locate the gear so it does not move around with shaft temperature and slop, but it still needs pull up clearance. You can't have it forced tight on the shelf, it has to float there.

The exact pull up is not critical, it just can never bottom out or be held in the air up off that locating face. If you have .010-.030 pull up it is probably OK. You want the shaft to move UP as the engine heats and not let the expansion force the gear down as the shaft expands. You always want the gear to just float on the block shelf that locates the gear face. That is what sets the gear height.

You have to make sure the gear is compatible with the cam and getting oiled.

 

Are you putting any assembly lube on the gear when you drop it in?

 

Yup

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