Hi guys I got back to looking at the 400 Pontiac that I said had no oil pressure to the top end. I pulled the distributor today to find the oil rod to be like one I have never seen before. I have posted a picture of it so maybe someone can tell me what could cause this to happen. I had stated that I just got the car and a cam was placed in the car not long ago. It quit running going down the road so he had it towed home. Never tried to start it after it was home. But when I got it home I got it started and it ran for about 2 mins. before I turned it off for values were tapping and no oil at the top. I think I now have a boat anchor. What would cause the rod to bend and the ears break off the top. Also as you can see it is really scared up. I also posted this as a reply to my old post so the guys that replied before can also see it. Thanks Chuck
I forgot to add that the end of the shaft with the ears broke off was at the top. And the end with the bent ears was in the pump. Could it of been placed in upside down? I see there is a shoulder and two small bumps on one end this was the end in the pump. thanks
I removed the distributor then used a magnet to pick up the two broken prongs. Then went back with the magnet and placed it on shaft and it came right up out of the top. I need a new shaft I think to see if the pump turns now or not. Thanks for replying.
I am not sure if the oil pump is turning at all. For I took the shaft out and I do not think I can get anything on it to try now. Unless I get a new shaft and install it. If you notice the end that was in the pump is now smashed together and there is no room to slid it over the flange in the pump.To get the motor to run I took off the distributor cap and found that the points were not opening. So I set them replaced the cap and it started right up. I am guessing when the car quit on the guy I got the car from that the points had come loose and closed that is why it backfired and quit running. Thanks for your help.
The drive was probably not installed correctly when the cam was changed. Other possibility is the pump picked up some debris that made it to the pan during the cam swap. I have seen pumps locked up from a single wire from a wire brush..
Yeah that's very concerning, the oil pump drive shaft should be installed onto the pump, then into the block... meaning it's installed and removed from the bottom, not the top.
the motor will be rebuilt or scrapped depending on the damage done. But I have never seen a rod so beat up. I like asking the questions on this forum for I get a lot of good answers. And learn a lot for we do not know it all. I will drop the oil pan one day this week and pick up a new pump and rod. I just want to see how it sounds with oil pressure. I would think the damage is done already. But it would sure be nice if it was not hurt yet.
That is a problem with all pontiac engines. The oil pump intermediate shaft is within 0.125" to the spinning cranshaft rear counterweight. The dowel that protrudes from the top of the oil pump gear shaft serves to align the oil pump intermediate drive shaft. If the dowel is broken and allows the intermediate shaft to hit the spinning rear crankshaft counterweight, the shaft will wedge between the spinning rear counterweight and the block. The shaft will then be bent just like shown in the photos.
That happoened to me in a 389 CI engine in my '66 GTO when the oil pump gear alignment dowel broke and allowed the intermediate shaft to come loose and wedge between the spinning rear counterweight and engine block. That time it was probably caused by fatigue of the old 1966 oil pump alignment dowel. It can also be caused by vibration of the intermediate shaft, causing the alignment dowel to break. It happend again in my 1962 Pontiac Catalina that was equipped with a fresh 1969 428 CI Pontiac engine when the engine was first started. That time it was a slug of heavy metal that was welded to the rear counterweight during balancing and the weld on the spinning rear counterweight hit the intermediate shaft and broke the alignment dowel on the oil pump gear drive shaft. That allowed the intermediate shaft to come loose and wedge between the spinning rear counterweight and block.
This problem is caused by the poor design of the intermediate shaft to oil pump shaft connection. The Pontiac intermediate shaft only has a slot to fit on the oil pump and relies on the alignment dowel on the oil pump gear shaft to keep the intermediate shaft in alignment. In 1955, the Pontiac engineers must have been temporily insane to design something like that. The Three Stooges could have done a better job.
There are some aftermarket intermediate shafts available for Pontiacs that have a slot but with a collar, similar to a Chevrolet, that will positively retain the intermediate shaft.
You might want to think about the timing chain and gears. Timing chain failure was common in Pontiac V-8's for years. Over the years I have had experience with trash from upper timing gear failure getting into the oil pump and locking it up. The "old screwdriver to try to turn the pump" trick should tell you if it's locked up. If it is, you'll need to pull the oil pan. If there are small pieces of plastic in the pan and pump, you'll need to pull the front end down. May not be a total loss, but lots of work.
I had a plastic timing gear failure on a 1969 Firebird 400, 4-speed with about 20,000 miles on the odometer. I was a cold 20 degree day and I just started off to work. The engine started missing and died in 100 feet at a traffic light and it would not start. I had it towed back home and I pulled the timing cover that weekend and the sprocket on the camshaft was stripped like an ear of corn. The engine did not run long enough for the smaller plastic gear parts to be ingested by the oil pump. The larger chunks would not have passed through the oil pump pick up screen....that is what the screen is for.
That is whe I decided to install a Crane Z-300 solid flat tappet camshaft and a Cloyes True Roller timing set. A month later, I blew the 3.36 rear end. The Pontiac Zone Office in Dallas authorized the local Pontiac dealership to replace the broken rear end with a 4.33:1, 4-pinion Safe-T-Track under the Pontiac 50,000 mile Drive Line Warranty. The dealership also replaced the driveshaft because it was twisted out of alignment when I broke and locked up the rear end.
Well it was for sure out of line. The pin from the oil pump is broken off an still in the shaft. If it was the end of the crank that the shaft hit what is the chances of changing oil pump and shaft and it running ok. It does not show any signs of heating up so maybe it was not run long with out oil pressure. Just grasping at straws now and hoping to get lucky. Thanks.
About 40 years ago, my younger sister had a 67 Firebird with a 326 in it. She called me one day for help because the car was dean on the side of a road. When I got there, I found the ENTIRE distributor was pushed up against the hood (???). Towed the car home, and after looking into the problem, I found the same sort of mess you're dealing with, but also a little bit more. There is a "boss" cast in the block, basically a "ring" that helps to support the shaft, and that entire boss was broken away. One trashed block. Wound up trading for a Bonneville with a 400 in it, and swapped engines. Stuck the 326 in the trunk of the Bonneville, and called the hulk hauler. I'd say check your block out just to make sure. Butch/junior stocker.
Several years ago some Pontiac aftermarket intermediate shafts were on the market that were machined incorrectly and a few thousants of an inch too long. When that shaft was installed and the distributor tightened down, the extra length forced the oil pump spur gear into the oil pump bottom plate and the gear would not turn freely and the oil pump seized up and broke within a few miles
I forget the company that made the bad oil pump shafts. It know the shaft was not made by a major company like GM, Sealed Power, TRW or Melling. After that, I checked the length of every Pontiac oil pump shaft before it was installed. All 1955-1979 Pontiac V8 oil pump drive shafts are the same length.
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