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proactive / preventative oil pump replacement?

ObscureMachine

Seatbelt Orifice Officer
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Sep 28, 2006
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World Headquarters
I've got a new stock oil pan I am planning to put on when I do the serp conversion. At the same time I'm going to be pulling the front axle to change c bushings. Does it make sense to change the oil pump while I have it apart, just for preventative maintenance. Or should I just leave it until I get a new engine in a year or so. The odometer on the 302 has 35,600 miles, but I'm pretty sure that's 135,600. Thoughts?

Thanks - jim
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,821
How is the oil pressure? Particularly at idle with hot oil.
I would be a bit more worried about the condition of the timing chain. And since you have the timing cover off already, easy change.
If the bearings are getting a bit sloppy, a high volume oil pump and stretch some more life out of an engine. But a high volume pump does stress the oil pump drive and distributor gear more. With tight bearings the extra volume will just be dumped out the bypass so no gain on a tight motor but still have the downfalls. High volume also is known to interfere with the oil pan. Although a high volume pump for an econoline apparently has flush screws for a little more clearance.

For reference, the factory one will be aluminum. Replacments are almost always cast iron. Might help you know if it has ever been replaced.

Be careful about how much you replace while it is apart, next thing you know you are doing a rebuild. timing chains are worth doing if you have the cover off, plan for it and be happy if you are not doing it.
 

blubuckaroo

Grease Monkey
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Jun 11, 2007
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Ridgefield WA
I wouldn't get a high volum/pressure oil pump for the above reasons.
Also, the higher the pressure, the more the filter will bypass dirty oil during cold startups.
If you have low oil pressure, seldom will it be the pump's problem. We always replace them with a rebuild, but most of the time the old one is still fine.
×2 on replacing the timing chain. My original nylon coated one was missing all the nylon at 80K.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
Rotate the engine by hand to top dead center. Remove distributor cap and look at rotor. Turn the motor backwards until you see the distributor rotor just move. stop and check the timing. If the chain slack allowed the crank to rotate backward until the rotor moved more than 15 Degrees its time to think about a new chain set. Normal wear is usually 6 degrees or so used. Reject time is about 13/16" on the damper circumference. Based on a 3 bolt 6.3 diameter 302 damper.
 

Lawndart

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Nov 23, 2014
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66030
I had my pan off recently, did not change the pump.
I did have to do the timing chain at 75k when it jumped a tooth. Old nylon mostly gone.
I would add - examine your damper and get it rebuilt if necessary
Damper Dudes are good and quick.
 

airman

Contributor
Bronco Guru
Joined
Nov 26, 2003
Messages
1,838
I would pull harmonic balancer and inspect and add front seal to this job. I just did the serp and pan, I did change the pump. Be sure your pick up is meant for the stock pan you intend to use. While you have all of this stuff out, its a great time to do a nice engine bay degrease (i used purple power). If you really need more work, motor mounts are right there too.
 

Broncobowsher

Total hack
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Jun 4, 2002
Messages
34,821
Don't pull the bearings caps off and look at the bearings, you might want to put fresh bearings in as well. Except the rear main where you might want to change the rear main seal.

That rabbit hole is getting deeper...
 

B RON CO

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Jun 29, 2016
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Statesville, NC
Hi, at that kind of mileage the engine has a lot of wear.
I would be more concerned if the engine was full of sludge. I have seen these 1970 era motors caked with so much sludge, and the oil pickup screen so clogged with crud, and in that case I would probably change the pump and clean the screen. Otherwise I would leave well enough alone.
Especially if you are planning on an engine change.
Good luck
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
I would fix the leaky dipstick tube while the pan is off. Another trip down the rabbit hole.
 

mtp71174

Full Member
Joined
May 8, 2007
Messages
204
I have a mechanic who suggest that any time has the pan off he changes the oil pump shaft to an ARP aftermarket. I have seen them twist off and they are know for it. Cheap insurance for the labor and cost involved.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
I have a mechanic who suggest that any time has the pan off he changes the oil pump shaft to an ARP aftermarket. I have seen them twist off and they are know for it. Cheap insurance for the labor and cost involved.

Yes, but what's the next weak link? The distributor gear and/or camshaft?
That shaft was designed to be the weak link. Compared to the camshaft, it's relatively easy and inexpensive to replace.
 
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