Rod knockin'

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
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Chris Haynes
Posts: 1952
Joined: September 7th, 2003, 5:18 pm
Body Type: 82A
Model Year: 1930
Location: North Hills, CA/ Pine Grove, CA

Rod knockin'

Post by Chris Haynes » March 12th, 2018, 9:21 pm

I have developed a rod knock. Time to pull the pan and see whats happening. Hopefully the crank isn't damaged. That would open a big can of worms. I guess that answered my question whether my engine had poured or inserted bearings.

birdacre
Posts: 332
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

Re: Rod knockin'

Post by birdacre » March 13th, 2018, 1:25 pm

i had the same thing. engine nice for a month and then a knock started. the pin bearings or connecting rod journals were tapered one end to the other. some of the babbit even looked like it had been patched. i was lucky to find a good used engine, yeah right, he warranted it, said to drive it for a few weeks before paying him 200 dollars. to this day it is great. very lucky. my first engine came with the truck and no history and was a crap shoot. hope yours is ok, post updates. kevin

User avatar
Chris Haynes
Posts: 1952
Joined: September 7th, 2003, 5:18 pm
Body Type: 82A
Model Year: 1930
Location: North Hills, CA/ Pine Grove, CA

Re: Rod knockin'

Post by Chris Haynes » March 14th, 2018, 10:19 am

It may not be a rod bearing. My engine is still running smooth at idle and low speed.When I accelerate to mid range or higher it has a ferocious hard rattle.

birdacre
Posts: 332
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

Re: Rod knockin'

Post by birdacre » March 14th, 2018, 5:26 pm

i also grounded each spark plug one at a time to hear where noise was coming from. an old man showed me to also listen through a 30inch section of garden hose as well to ascertain the noise. hope all is well. kevin

Stakebed
Posts: 1143
Joined: June 14th, 2007, 7:29 pm
Body Type: Grainbox
Model Year: 1929
Location: Illinois

Re: Rod knockin'

Post by Stakebed » March 14th, 2018, 7:29 pm

And your SURE its from inside the engine? Could be flywheel/clutch related. Does it do it in neutral when your stopped and revving the engine? Clutch depressed and revving VS released?

Is it only under a load? What about when in reverse? driveshaft can transmit sounds to many places...

MrBill
Posts: 6
Joined: February 14th, 2018, 3:11 pm
Body Type: CCPU
Model Year: 1929

Re: Rod knockin'

Post by MrBill » March 16th, 2018, 3:55 pm

mine recently started knocking too...when I shorted out the plugs number 3 cyl was the one and it made a double knock then...pulled pan and found piston pin loose in piston and others had loose pin bushings

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