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cam gear ate up my oil pump drive gear

The1AndOnlyBug

NAXJA Forum User
Location
Denver, Co
So little history, I bought this engine which is from an 87-90 MJ bored .30 and about 60k on a rebuild, and put it in my wife's '01 XJ with a few modifications. I bought the engine fairly cheap because the P.O. noticed wear on the dizzy gear when he went to sell it.

I've been having problems with it lately with it dying and throwing a crank position sensor/cam position sensor code, well 2 crank sensors later and one cam sensor I decided that it may not be it, and while I was at the junkyard yesterday I grabbed a oil pump drive gear unit for $25, so when I did tear into it i had it available.

Well I go to take the wife to work today and stop at DD's while I'm sitting there I hear a funny noise and the jeep stalls, I start it back up and it still sounds a little funny, then I notice i have 0 oil pressure and shut it down. I pull the camshaft sensor and oil pump drive gear and below is what I find.

My question is how long do I have before the camshaft fails completely, and can I drive it at all until then. I know it's all speculative, but I'm just trying to figure it all out.
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And I need recommendations on a new cam, I plan on keeping this jeep long term, it's a southern vehicle without an ounce of rust I brought from VA to ME.
I plan on the long run to stroke the engine (after replacing the head with a 7120) and building this virgin beauty into a off roading machine!

After buying my wife a new vehicle...... lol

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That may be true but at least it's only in the sump so the filter should be picking it up!
I hope you use good filters and change the oil regularly!
 
maybe so but that's a lot of metal running around your engine
Yeah I know, as it's my only vehicle I can't take the time off of work to put a new engine in again.... Honestly I'm gonna have to take my chances with just changing the oil and filter for now. Somebody told me that the gears on the oil drive pump are aluminum, so hopefully it doesn't do as much damage as cast iron would do. If worse comes to worse I'll buy my wife a new vehicle and rebuild a 4.0, and drop it in when I get a chance.

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Yeah I know, as it's my only vehicle I can't take the time off of work to put a new engine in again.... Honestly I'm gonna have to take my chances with just changing the oil and filter for now. Somebody told me that the gears on the oil drive pump are aluminum, so hopefully it doesn't do as much damage as cast iron would do. If worse comes to worse I'll buy my wife a new vehicle and rebuild a 4.0, and drop it in when I get a chance.

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Jeeesh.

They don't know what they are talking about.

That gear is steel. That gear drive the oil pump, there is a better chance that your oil pump is fried and that's what caused the gear to get chewed up.

It's yours, do as you will.

It won't last.
 
In a effort to buy time, I would a least pull the pan, clean it, and put in a HV pump. Regardless of the filter your still putting garbage thru the pump!
 
in my experience the reason the oil pump drive and the cam gear got worn out is because of too thick of oil. it was rebuilt before so im guessing it has a high volume pump in it now. it probably had really tight oil tolerances and put a lot of stress on the gears. with that said if it was mine and I was in your shoes I would pull the pan clean it out put a new high volume pump in it and then run a thinner oil like a 10-30. it might drop the oil pressure but it wont stress those gears so bad. and put an after market oil pressure gauge on it.
 
I'm sure you've checked for distributor shaft binding, but how about end play where the dist shaft indexes into the oil pump drive? You can check this by pulling up on the rotor end of the shaft with the dist installed and bolted down. There should be a slight amount of play there. When I installed a new dist in my 96, it was very tight and actually leaked oil by the gasket. I removed the dist and filed the end to provide a slight clearance with the oil pump drive.

I believe something was binding to strip the gear that badly...
 
I'm sure you've checked for distributor shaft binding, but how about end play where the dist shaft indexes into the oil pump drive? You can check this by pulling up on the rotor end of the shaft with the dist installed and bolted down. There should be a slight amount of play there. When I installed a new dist in my 96, it was very tight and actually leaked oil by the gasket. I removed the dist and filed the end to provide a slight clearance with the oil pump drive.

I believe something was binding to strip the gear that badly...

Get a large long screw driver and turn the pump over by hand. There will be a little resistance, but if it is really stiff something is wrong with the pump. Jammed pressure relief valve or more likely too little gear clearance from the pump lid. The pump lid gasket is part of the gear clearance, maybe somebody forgot the gasket (just a wild assed guess).
 
I lost an engine due to a bad oil pump. It took out the distributor gear.
 
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