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Yesterday, my Rinky Dink Jeep tried to kill me. The on-going saga of my efforts to resuscitate this long forgotten and abused  CJ5. After a week or two spent squirting Sea Foam & JB Blaster in the cylinders I actually got it running on Saturday.  I had gone through the fuel system completely, from filler hoses to the carb. Everything is either new or re-manufactured, with the exception of the hard lines which were flushed with acetone. Primed the fuel system. New cap, rotor, wires, plugs gapped. Cranked and it fired. It was apparent that the timing was way retarded, as it barely ran at idle and died with any throttle given. Figured to set the timing only to discover the distributor seized solid. "Like a rock' as the Chevy guys would say.

Turns out the distributor is also sitting proud of the housing by 8-10mm. It has been sitting like that at least for 10 years, without a hood, in the So Cal Inland Empire. Hmm. Alum on Alum out where the sun and the stars shine. Not good. Anyway, tried all the usual, tapping up, down and sideways. Soaked in JB Blaster. Even the Milwaukee hot air gun. It wouldn't budge. Sat night decided to try the 50/50 Acetone & ATF Miracle cure. Wrapped a shop rag around the shaft and let it sit over night. My restless ponderings while horizontal led me to believe that I needed more heat. Bright and early Sunday AM, with a cup of joe in one hand and a propane torch in the other, I uncover said jeep and dry off the area. I didn't so much as touch the flame to the housing when it ripped off a huge bang. Blew the valve covers off the heads. That was unexpected! 

Proud to say didn't spill any of the precious from the cup. Neighbor at the end of the street heard the bang and looked in time to see me standing there with a smoke cloud above me. Obviously set off the internal fumes. Never in my 48 years of playing with engines has this ever happened to me. I may be a bit slow but I eventually figured out that the distributor hold down bolt is through drilled into the timing case cavity and I flashed it off, twice. Did it a second time today to a lesser degree. That is when I deduced the through drilling. Sharp as a marble one might say.

Anyway.. the damn distributor is still stuck. I rigged up a small slide hammer today and  tried popping it. Still nothing. 

NOW the question; Is it possible to remove the oil pump and drive the distributor out via the bottom??

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Rinky Dink...Well, I certainly appreciate your candor and humor!  Are your eyebrows singed?  This is not an uncommon occurrence.  Open flames and crankcase fumes are a volatile mix as you discovered.

The slide hammer was innovative but could bust the aluminum distributor housing.  As for driving the 304 AMC V-8 distributor out from the bottom, this will work readily if "stuck" is caused by distributor shaft and camshaft gear bind.  It would also work, though somewhat harder, if the distributor housing is binding in the timing cover bore.  You really have little choice, however.  Fortunately, the oil pump is external and accessible on these AMC V-8s.

If you do remove the pump to drive the distributor shaft upward, inspect the pump bore (aluminum) in the timing cover.  These timing covers are notorious for wearing badly in the pump area.  The alloy is the outer wall of the oil pump.  There are aftermarket timing covers available for this engine if you need a complete new cover, which begs a new timing sprocket/chain set at the same time if this engine has miles.

I have always done the Melling High Volume Kit on these engines and the Buick V-6/V-8 engines as well.  The kit includes a pump end plate spacer and longer pump rotors/gears that result in more oil volume/flow.

Let us know how this turns out.  Glad you avoided the burn ward and still have your hearing...Eh?

Moses

 

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Zinc plated 7/16ths round stock is about 30 thou smaller dia than the .465" pump shaft. Cut a piece about twice as long as the pump shaft. Fits the hole nicely. Tried a heavy hammer. Nothing..

Got out a small bottle jack to push against the round stock. All that did was jack the engine up.

Applied more heat. Nothing moving. I'll try the heat again tonight.

Seriously looking at a new timing cover at this point. If it comes to that, I'll check the timing chain for wear. R & R as needed. 

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Got home tonight and tried one last trick. Air chisel/hammer against the 7/16ths rod.

Nothing moving.

Ordered the new timing cover with oil pump kit from Crown. I hope it is better than some of the reviews I have read. 

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Rinky Dink...What can I say, other than, "Wow!"  Will be interesting to see what is holding that distributor in place...So the timing cover pump bore is shot or scored?

Let us know what you think of the Crown timing cover and pump pieces.  This is the last new (not NOS) casting available, likely an off-shore replica.  Value your opinion...big help for others.  Photos always welcome!

Curious whether you'll salvage the distributor or be looking for another one.  What year is the Jeep 304 V-8?  Motorcraft distributor?

Moses

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Moses,

The pump bore didn't look too scored. I have not bothered to measure it as it is being replaced. I will be checking the new one carefully. From what I've read, the Chinese castings are missing the cast-in steel sleeve that should be in one of the through bolt holes. We shall see.

It is a Motorcraft magnetic distributor. We will see if it is salvageable, hopefully.  

The ID plate indicates it is an original V8 build. I have not found the block casting numbers. The thing is quite caked in greasy dirt on the underside. Per the head casting #, the heads are of '74 vintage. From what I have read there is no difference with the later heads. Port, chamber & valves sizes are unchanged.

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Alright, Cover is off and obviously toast. Same with the distributor and timing chain. Seems at some point this cover was in bad shape with corrosion as it has been built up with weld on many of the mating surfaces, especially around the two main water ports. They managed to lose about half of the area of the port. IMG_20170325_143930748.thumb.jpg.e7dd17de24b875f4071d04b293f11d97.jpgIMG_20170325_143919461.thumb.jpg.347ef555306d415bbd7a026cdff99e2e.jpgIMG_20170325_143822896.thumb.jpg.3b8d9055d84634c0ca33593629e8820f.jpgOn closer inspection it is obvious the oil pump cavity is worn also.  

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Rinky Dink...Replacing this cover was the only choice.  Do you need the Melling High Volume pump kit, or are you okay with the renewed cover and pump?  Stock oil pressure and volume is usually adequate for a stock AMC 304 V-8 engine, especially with a new timing cover (pump "housing").

Good job...best you can do under these circumstances.

Moses

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  • 2 weeks later...

Ok, managed to salvage the dist drive gear. The rest of this mess is scrap. The cam drive chain is beyond the 1/2" play spec so I ordered Bulltear's USA made, double row chain & sprockets. While waiting for that to arrive I blueprinted the oil pump that came with the new Crown Timing case. The pump end play needed to be set and also the oil passages needed cleaning up, of some flashing and some obvious casting short cuts. A couple of sharp edges have been opened and radiused. The steel tube insert is in the cover. It was pressed in after the casting was made. I had read that some cheaper covers were missing this feature. Plastigage showed something greater than .007" clearance on the gears & end plate. Measured the new gasket @ .017." Tried fitting it without a gasket but that was too tight. Couldn't find any loose gasket material thinner than the new gasket at the auto parts store so I scrounged an old paper grocery bag. It measured .007." I cut it to fit, applied Permatex Non-hardening liquid sealer and bolted it up. Plastigage shows it is @ .004." Perfectly between the spec'ed .002-.006. Pump spins  free and is packed with vaseline I'll be making a priming tool from the remains of the old dist. The new pump end plate has also deleted the filter by-pass. 

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Pictures worth a thousand words, Rinky Dink!  So, you'll use an oil filter with a built-in bypass to make up for the lack of a bypass valve in the new filter stand.  Innovative approach to the end plate gasket.  I like your attention to detail on the pump gear clearance, flow and the end play.  Did you consider the Melling "High Volume" kit if it's even available?  Longer gears and a pump housing spacer equals more volume.  

Glad you mention the Vaseline/petroleum oil packing of the pump gears and cavity before attempting the engine priming.  Many bearing sets have been lost on initial startup with a new pump/timing cover or even from draining the oil pump by simply removing the end cover.  You've taken the time-honored approach for AMC and Buick V-engines.  I like the double row roller timing chain, too, that's longer life and more accurate for valve timing.

Will you be able to reuse the distributor, or are you going aftermarket here?  There are a number of performance distributors available for the AMC V-8 engines.

When this began, were you aware of the cranking compression or better yet this engine's leakdown per cylinder?  (I've run leak down static tests on engines setting on the floor at recycling yards, this is a major advantage of a leakdown tester.)  If the cylinder heads and piston rings seal well, this would help justify your premium effort on the timing cover, oil pump and chain/sprockets.  Are the camshaft and lifters in good shape?

Nice work...

Moses

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Hi Moses,

That distributor was toast. Even with the cover off and using a 2lb lineman's hammer it wouldn't budge. Actually bent the steel rod trying. I was able to pick up two OE dist's along with a new wire set, ignition control box & coil for $40. One of these distributors is a new re-manufacture!

I call this thing Rinky Dink because it "was" cheap $800. I figured to get it running, smogged & registered and just have a cheap jeep for when I go desert camping. What it has turned into is the rabbit hole straight out of Alice in Wonderland. Fixing one issue just leads to another. 

So, I figured I was halfway there so I may as well change out the rear main seal. Pulled the pan and glad I did. The inside looked like a refugee from an oil refinery waste site. Sludge & carbon bits 1/2" deep and stuck like glue. Between the inside and outside, that pan took at least an hour to get reasonably cleaned up. Don't know the condition of the cam. For the brief period it ran, it didn't sound bad. I would like to put a mild cam in it but at this point it is a question of throwing good money after bad. I don't know which way it is going to go.

Most of my mechanical knowledge is related to motorcycle engines.  I am curious as to the procedure of a leak down test without pulling the manifolds? How do you do it? 

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Yep, Alice in Wonderland, we've all been there!  Here's my rundown on a leak down test.  I also did an article at the magazine on motorcycle leak down testing.  My Honda XR650R is the example.  

You'll be all over this form of testing.  A static engine on a cherry picker, engine stand or shop floor can be tested, the engine doesn't need to be in the chassis!...Moses

 

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