Ford 9N Front Knocking

Currently using a 9N to do mule work around our hunting grounds (Northern Michigan), changed the oil over the weekend (10W-30) and thought there may be a starting issue. We tried pull starting to no avail, but then put the battery up on a charger and it fired up.

After about 5 mins started hearing a knocking sound in the front of the engine, but there wasnt a rhythm to it. Then noticed there was coolant leaking from the front of the fan. Im assuming my water pump is bad, but would that also explain the knocking in the front of the engine? It sounds like the knocking is coming from where the fan is but its hard to determine.

The fan blades on some of those N's can come close to hitting the lower radiator hose - sometimes so close that going over slight bumps & rough ground will flex it just enough that the fan actually touches the hose, especially if the rad's moved or things have flexed just a touch, or if isn't fastened/shimmed quite how it would have left the factory. I'd be willing to bet that's what happened on yours - it probably 'knocked' occasionally and sporadically when a fan blade was just barely nicking the hose, and it's either cut the hose or (hopefully not) cracked the stub pipe on the rad where the hose attaches. Happened exactly like that on one of my N's one time - a 2N we use for logging a red pine plantation in tight quarters where the small/nimble N is perfect for getting in there and skidding the smaller logs. You go over a lot of bumps/stumps/rough ground logging, and I started to hear a tick/knock - especially when only one side was climbing over a log or something. I didn't think much of it until it started leaking coolant - fan had cut through the hose.

I noticed on another N that the replacement fan has blades just about 1/2 shorter than the original, which gave a little more clearance to the rad hose.

Further to my last reply, I didn't read thoroughly enough and just saw now you mentioned coolant coming 'from the front of the fan'. If this is the case, then my last reply was probably not the problem, and it could certainly be the water pump. I haven't had a water pump go bad on an N (yet), but when one went on one of my Fordsons it made one holy heck of a knocking just before it went. In that case, the bearing was bad and the whole pump shaft had tilted down so the impeller blades were hitting on the casting.

When we looked at the fan it didnt appear to hit anything while hearing the sound, but I wonder if that sound could be something you dont see as its knocking elsewhere? I just know it wasnt something like a rod or piston because there was little rhythm to it. Although when rpms increased it did appear to become more prominent.

(quoted from post at 07:44:04 08/21/23) Currently using a 9N to do mule work around our hunting grounds (Northern Michigan), changed the oil over the weekend (10W-30) and thought there may be a starting issue. We tried pull starting to no avail, but then put the battery up on a charger and it fired up.

After about 5 mins started hearing a knocking sound in the front of the engine, but there wasnt a rhythm to it. Then noticed there was coolant leaking from the front of the fan. Im assuming my water pump is bad, but would that also explain the knocking in the front of the engine? It sounds like the knocking is coming from where the fan is but its hard to determine.

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There is a kingpin (that's what I call it, N-people might have a better name) that connects the front axle to the tractor.

The radiator and such is mounted to the axle. The water pump, fan and stuff are mounted to the engine block.

The kingpin connects the axle to the engine block.

If the kingpin is worn, it lets the position of the block change, relative to the axle. And, maybe depending on how much torque you put on the tractor, that position might change. Pulling hard would lift the block, relative to the radiator. Braking would lower it. Just revving the engine puts a sideways twist on the block.

Either way, if that pin is worn, you may get intermittent knocks.

I know that "knocks" and a fan hitting a shroud doesn't seem to go together... but these old tractors have heavier metal in the fans and shrouds than a modern compact tractor has in its engine block.... kidding...sorta...

Anyway...

https://fordtractorcollectors.com/front-kingpin/

A water pump with bad bearings will knock and rattle around.

Take the belt off and feel for looseness in the pump bearings. But if it's leaking it will need to be replaced anyway.

Start it up with the belt off, see if the sound is gone.

While you're there, check the crank pulley, be sure it is not loose on the crank.

Also the 10w-30 oil is a little light, especially in warm weather. I like 15w-40 diesel oil. It is a little heavier and meets the needs of the old flat tappet, non emission engines better.