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| | | Joined: Aug 2009 Posts: 163 Shop Shark | | Shop Shark Joined: Aug 2009 Posts: 163 | I have a noise that I cannot locate currently so just as a thought, can I drop the oil pan and re torque the rod caps?
The noise I thought was the driveline coming separated at the yoke so I disconnected the drive shaft cover and tightened those 4 bolts with a drop of thread locker. The u joint could be swapped out so that is on my shopping list for future. | | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | Whether you can or can not drop the pan depends on the engine and what vehicle it is in. | | | | | Joined: Aug 2009 Posts: 163 Shop Shark | | Shop Shark Joined: Aug 2009 Posts: 163 | Sorry. 1947 3100 late full pressure 235 | | | | | Joined: Aug 2009 Posts: 163 Shop Shark | | Shop Shark Joined: Aug 2009 Posts: 163 | I do have a 4" drop axle on it | | | | | Joined: Jul 2013 Posts: 200 'Bolter | | 'Bolter Joined: Jul 2013 Posts: 200 | If by chance it is a rod, re-torquing it at this point won't fix it. But you can check other things while your inside the engine...crank thrust, cam thrust, broken pistons skirts, etc...
We cannot solve our problems today using the same thinking we used when we created them!
Albert Einstein
| | | | | Joined: Nov 2006 Posts: 2,544 Shop Shark | | Shop Shark Joined: Nov 2006 Posts: 2,544 | If its a rod you can have it running and pull spark plug wires to narrow down which cylinder is making the noise. You are better to diagnose a little more before taking things apart. I my opinion anyway. | | | | | Joined: Aug 2009 Posts: 163 Shop Shark | | Shop Shark Joined: Aug 2009 Posts: 163 | Thank you I will try that | | | | | Joined: Feb 2004 Posts: 29,771 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,771 | The late model 235 has insert-type rod bearings that cannot have the clearance adjusted by changing shims like the older Babbit bearing rods could. By the time a knock becomes audible, there's a possibility that too much crankshaft damage has been done to correct the problem even by changing the bearings. Once the pan is off, inspect all the rod bearings for wear, and measure the crankshaft journals with a micrometer for wear. They should be round and straight, with little to no visible scoring, out of round, or taper wear.
Other possible sources of a knocking noise can be worn main bearings, cracked or loose-fitting pistons, wrist pin wear, or foreign matter or carbon buildup on top of a piston causing contact with the cylinder head. Does the noise only happen with the truck in motion? If so, it's probably not an internal engine problem.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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| | | | | Joined: Feb 2011 Posts: 1,362 'Bolter | | 'Bolter Joined: Feb 2011 Posts: 1,362 | If a con rod needs re torque there will be chunks in the oil pan, if the nuts/bolts are not tight it won't last long.
Kicking self for selling off my Taskforce trucks.
Still looking for an LCF or conventional big bolt in decent shape.
As of 10-26-2022, A 55.2 Taskforce long bed now the work begins
| | | | | Joined: Sep 2008 Posts: 872 Shop Shark | | Shop Shark Joined: Sep 2008 Posts: 872 | Is it RPM dependent? At idle only or worse at speed?
Do you have a mechanics stethoscope (harbor freight sells an OK one for a few bucks). That can help narrow it down to a cylinder/top/bottom end.
To help locate it I would remove the fuel pump and the fan belt.. anything external to the engine that makes noise and run the motor using the stethoscope and listen to the motor in a systematic way... the closer you get to the noise the louder it will be. Its a fairly helpful tool.
You've already rules out valve lash and done a compression test?
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