Hello all,
I am in the process of putting my 1949 Hudson coupe back on the street. It only has 48,000 original miles so it is in decent mechanical shape for it's age. I have just got the engine back together after a thorough cleaning sealing and rebuilding all the components such as the distributor, carb, pumps etc. Runs and sounds great except for one thing. Occasionally I get a front end rattle in the engine only at idle rpms. Revving the engine up takes it right away even in the slightest amount. almost as if something is in some harmonic unbalance.
In troubleshooting I removed the belt and qualified my generator, fan and water pump as not being the source of the issue. Removed fuel pump afterwards with the same result. Completely removed water pump to get a better look at the front pulley and it is definitely coming from that area if not inside the timing cover itself.
Could the timing chain slack make this loud of a rattle? Could the very little free play in the crankshaft cause noise if slightly off balance? I have noticed in setting the carb that the engine sometimes hunts a slight bit for idle rpm and coming off high rpms doesn't come down to the same speed. Sometimes will even die unless you pump fuel into it.
Anyone experience this kind of metallic rattle on the front end only at low rpms under no load?
Thanks
Andy
At 48,000 miles the original timing chain is probably getting a little tired. have you checked that the vibration dampener bolt is really tight? My Hornet had a similar rattle, and the dampener was moving slightly on the keyway. I tightened the nut with a blunt chisel and hammer, and the noise went away. Worth checking. Otherwise you should take the case off and check the chain, not a big job. Good luck,
Geoff
I know this timing chain slack issue has been beat to death on forums all over the web from other new Hudson guys like me so I will ask a similar question again. pulled the dampener off today and it seemed plenty tight and snug. I suspect no problems here. pulled the timing cover off and found a chain on the loose side with a full free play of 1/2" slack. I hear this is normal for any car with mileage, but I have a separate inquiry...
Would this chain slack at a given rpm slap or hop the slide on the inside cover to give me my rattle? What purpose does this slide composite block with the hard plastic dowel really accomplish? I suspect possibly it is in a harmonic bounce on the tight side of the chain and then it begins slapping the inside timing cover? What purpose does the plastic dowel have? It will be hard to keep in the slide when you go to put the cover back on without it falling off before it is on top of the chain. I plan on replacing the chain regardless. Has anyone experienced a bad slider? Noise from a slider or considered just leaving one off all together?
Thanks!
I can't address the dampener issue, but I would suggest that you replace both sprockets as well as the chain and seal. Turn the crank spacer around so the seal wears on a different portion.. It's not much fun getting in there.. You may as well do the job right the first time.
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