Chewed the camshaft gear...

[JR74CJ5]

Well it happened... My DUI distributor swap apparently was not thought out as far as I thought.

I assumed the info Summit gave me was correct, and the info I had seen was correct, but my AMC 304 V8 did apparently have a soft gear and DUI a hard gear.

I ran this set up for 7 months... But during my trip last week to the Rubicon, it finally died. Confirmed the camshaft gear is chewed...

So I found new gear sets (distributor and camshaft) Omix-Ada 17423.03 - Omix-Ada Distributor Drive Gear Kits - Overview - SummitRacing.com now just wondering what i should do.

Planning to drop the oil pan, check everything out, put a magnet in there, check and flush the oil pump, check out the timing chain while there, pull the heads off and look at the cylinder walls and lifters / rods...

Am I going overboard or does this all sound reasonable?

Anything else I should check?


I did make it a ways through the Rubicon trail though, so trip report and pics in the next few days...

~ JR

 

[Torxhead]

Hopefully the oil filter caught most of that . A hardness inspection would reveal more about your disaster. Make sure the replacement gear is not too hard also. I am quite suprised that a company like D.U.I. would sell a distributor with too hard of a gear. Tough break though.

 

[JR74CJ5]

ah it was my own move... I've read everywhere to check the cam gear / distributor gear for matching metal type / strength... Also read a lot of places, that the AMC V-8's were immune to the issue.

But alas, here I am... lol

 

[Old Dog]

That bites a big one.
I would drop the pan and check it out for pieces just because.
Try to flush some of the old oil out while the pan and valvecover is off.

 

[derf]

I never install any distributor that doesn't have a matched set of gears between the cam and the distributor.

Get these, install them and you won't have to worry: Bulltear-Online

You'll want to drop the oil pan and see what's in the bottom.

While you have the timing cover off to replace the cam gear, check the timing chain for damage. Also, disassemble the oil pump and make sure there's no damage there too. While you have the oil pump apart, it's easy to rebuild it and install an oil pump mid plate: Bulltear-Online

If the oil pump housing is gouged, you need to replace the entire timing cover. If that's the case (and you have the extra money) get the nickel plated version. The plating isn't for bling, it makes the walls of the oil pump cavity a lot stronger and resistant to wear. Bulltear-Online

 

[tarry99]

JR
Hate to tell you but if those shavings got in your oil galleys the whole motor needs to come out and be taken apart.
You said you ran it for a while and I guess you could look at the bearings and cylinder walls and see how much debris got moved around.

 

[JR74CJ5]

JR
Hate to tell you but if those shavings got in your oil galleys the whole motor needs to come out and be taken apart.
You said you ran it for a while and I guess you could look at the bearings and cylinder walls and see how much debris got moved around.

Hoping the oil filter will have caught the all (if not most) of it, but yes I plan to check thoroughly.

A total tear apart and re-build from inside out wouldn't be a bad thing at all, just got to talk the lady into it, and ensure I have the cash flow for what I want to do "while in there" as they say.

Also my jeep would be down for a little longer than ideal.

Had "planned" to get a build-able 304 to take lots of time on getting done up the way I want, then just swap so little isf any down time, but hadn't got that far yet...

Derf - Thanks for all the links... Was lurking there a little earlier today.

An extra 60.00-70.00 to get made in USA and "better quality" gears may not be too bad. I had the summit ones linked because they "are" going to help me get the new parts discounted due to partially being their fault, but in truth, the fault lies with me, so not sure if I'll force them to or not...

 

[IOPort51]

This blows chunks for sure but I guess you have no choice but to bite the bullet and build an engine.

 

[tarry99]

Hoping the oil filter will have caught the all (if not most) of it, but yes I plan to check thoroughly.

JR,

When you take it apart pay attention to the bearings and cylinder walls . you'll be able to see how much the shavings migrated around. Keep in mind the oil has to travel to the filter to get there and some of the debris will just hang out in little spots throughout the motor.
Cut the oil filter in half and look into it.
Big chunks are easy to see and deal with like a broken rod , its the small ground up shavings that really do the damage and will continue to do so until the motor has been properly flushed / boiled out and the oil galleys rooted out with a long brush. We like to epoxy magnets in the lifter valley and other places that debris can hang out to catch loose metal.
Its not really a big deal its just the motor needs to be taken down to a bare block.

 

[jasonmark1993]

Id put the new gear on and run it (timing gear has to be good too) and see what happens.

If you're going to tear it apart to inspect you might as well just rebuild the whole thing.

Can you post a pic of how much of the gear came apart?

 

[coldair]

Looks like time to upgrade to 360 :-D

 

[JR74CJ5]

This blows chunks for sure but I guess you have no choice but to bite the bullet and build an engine.

Might just do that lol

Hoping the oil filter will have caught the all (if not most) of it, but yes I plan to check thoroughly.

JR,

When you take it apart pay attention to the bearings and cylinder walls . you'll be able to see how much the shavings migrated around. Keep in mind the oil has to travel to the filter to get there and some of the debris will just hang out in little spots throughout the motor.
Cut the oil filter in half and look into it.
Big chunks are easy to see and deal with like a broken rod , its the small ground up shavings that really do the damage and will continue to do so until the motor has been properly flushed / boiled out and the oil galleys rooted out with a long brush. We like to epoxy magnets in the lifter valley and other places that debris can hang out to catch loose metal.
Its not really a big deal its just the motor needs to be taken down to a bare block.

Yes Sir, you are very correct. I am not sure how the oil circulates (path of flow) around that particular area, but there very well may be a lot of damage from small shavings, especially from being ran for a little more than 7 months from the original date of DUI install

Id put the new gear on and run it (timing gear has to be good too) and see what happens.

If you're going to tear it apart to inspect you might as well just rebuild the whole thing.

Can you post a pic of how much of the gear came apart?

Thinking of doing this, and getting a hold of a build block to build the way I want over the winter and swap in next spring...

As far as how much of the gear, from what I felt and seen through the small distributor shaft hole, most all the gears are "sharpened" making me think a good amount of each tooth has been ground off, and there are obviously at least 1 or 2 teeth in a row completley gone. (I say obviously because if turning over the engine while cap is off distributor you can clearly see a "laps or pause" in the turning of the rotor.)

But yes after replacement, I'll have some pictures up of the carnage.

Looks like time to upgrade to 360 :-D

I know right? I think it would be easier to find a 360 block than a jeep 304 block to build... hmmm...

Thanks all,

Planning to tear into it next couple of weeks, and check out the extent of the damage best I can hopefully without complete dissasembly. Because as stated, if I tear it that far down for inspection, I may as well be throwing new parts in while i'm there...


~ JR

 

[jasonmark1993]

Ive actually never seen one of the dist. gears after this has happened.

Is the dist. gear still good or if its chewed up can we see a picture of it?

 

[JR74CJ5]

Ive actually never seen one of the dist. gears after this has happened.

Is the dist. gear still good or if its chewed up can we see a picture of it?

Distributor gear looks bran new But Yes I'll include one of it as well.

That's what makes me think its a "hardened gear chewed softer gear" problem not a "I'm an idiot and didn't shim it right" problem :laugh:

 

[derf]

Ive actually never seen one of the dist. gears after this has happened.

Is the dist. gear still good or if its chewed up can we see a picture of it?

I have a picture of one that got chewed up but it's on my PC at home. I'll post it sometime tonight if I can.

 

[JR74CJ5]

Here's some dirty carnage pics of the gear:

So I replaced the gear on the cam (fit kinda tightly...) but got it on.

BUT, the distributor gear absolutley will not fit my distributor... It is now stuck, as I tried heating it up to get it on... SO... I'm "grrrrrrrr'ed"

While researching this morning, I found a Amazon review stating the same problem with the same kit for the same engine... So it appears that the Omix-ADA gear set is NOT a good option...

Called up Summit this morning, and with just a little haggling, Got them to give me a smoking deal on the MSD set with a credit on top for the Omix ADA ones i just bought. Out the door under $45.00 for $102.00 worth of gears... Did some research on the MSD ones and appears they have a good rep and should work...

Hopefully these ones will work out.

MSD Ignition 8005 - MSD Iron Distributor Gears - Overview - SummitRacing.com
MSD Ignition 8007 - MSD Iron Camshaft Mounted Distributor Gears - Overview - SummitRacing.com

We shall see...

Now i have to get the Omix ADA gears off! And the one on the distributor will probably take grinding it almost through and hitting with a punch. Hoping it will be about like removing the retaining ring on the rear axles to get old bearings off.

Really regretting buying the DUI distributor at this point, BUT i felt it was a good upgrade at the time, and needed to purchase a new distributor anyway...

So the Saga will continue, I'll keep this posted / updated.



~ JR

 

[Old Dog]

Man it ate that baby up.
Omix-ada strikes again. I really don't know how they stay in business.

 

[tarry99]

JR

So does that gear look like that 360 degrees?
Was your distributor loose when you took it off........and is there excessive end clearance in the distributor shaft up/down?
What does the gear look like on the cam?
Take a standard fine file and just drag it across the gear and see if it glides over it or takes metal off .............pick a spot that isn't chewed up.

 

[tarry99]

JR

Check that , what does the distributor gear look like?

 

[IOPort51]

do you have a small three jaw gear puller to get the gear back off the distributor??