The major differences between the 9N and 8N are that the 8N has a slight bit more horsepower, has a 4 speed transmission compared to the9N's 3 speed, and the 8N has an improved hydraulic system.

The 8N has position control -- essentially the tractor will hold an implement at whatever position you set it at.  The 9N has only draft control, which will not.  Without going into tons of detail (we can if you want) the 9N is fine for anything you want to do EXCEPT if it requires position control. 

The Zane Thang was developed for precisely that poblem; it is an external device that gives position control to tractors like the 9N that lack it.  I do not have first hand experience with Zane's Thangs but I hear that they work exceptionally well. 

Depending on what you want the tractor to do and how "old fashioned" you are willing to be with things like brush hogs, it may not matter.  Older equipment designed for use with pre-position control tractors used a solid top link and a chain & rack system where you lifted the implement up, set the chain on the rack where you wanted it, and let the hydraulics all the way down.  The implement then hung from the chains & top link at that height.  Not as handy as position control but it worked for many years. 

Pete P.
Harborcreek, Penna.

Per original Ford literature, the 9N is 23.87 belt HP max, rated belt HP = 20.29.   The 2N is same.  The I&T shop manual lists 9N & 2N at 23.6 HP max belt, 16.3 HP max drawbar and the 8N at 27.3 HP max belt, 23.2 HP max drawbar.  Sorry, don't have original Ford specs for 8N and don't know why Ford data is slightly off from I&T. 

The 8N is more powerful because the compression ratio for later 8Ns is 6.5 : 1 compared to the original 6.0 : 1.

Hope this helps,

Pete P.
Harborcreek, Penna.

Jay --

I'm afraid I can only speak with certainty on a couple of your questions, but here goes --

1.  SN is located on a flat spot of the block casting near the oil filter housing.  In your case it will start with 8N.  Stamps used are a wierd font and very shallow so you'll probably have to use variable light techniques and clean the numbers up well.   SN refrences are available, but check other sites too.  I personally like (besides this site) N-Complete and Yesterday's Tractors (www.n-complete.com, www.ytmag.com) as they have active boards and refrence sections.

2.  The engine is a 120 CID L-head 4 cylinder (some call it a 119.)  The basic engine is the same for 9N, 2N and 8N although there was a compression increase with the 8Ns yielding a few more HP.  Many 9 & 2Ns were re-engined with 8N engines and I've seen a couple swaps the other way too, so if you SN comes back to another model that's what happened.

3.  Rebuild kits are available lots of places, but personally I love dealing with the N-Complete folks as they'll help you over the phone and are very knowledgeable (just my $ 0.02)

Hope this helps a little,

Pete P.
Harborcreek, penna.

The generator terminal should not be shorted to ground, but it is connected to the generator windings which will only show a very low resistance to ground.  If the poor machine were jumped with 12v direct to the battery the cut out relay is probably fried.  Good news is it probably protected the generator. 

Start the tractor and bring it up to about 3/4 throttle.  I assume the ammeter at this point will show discharge.  If that's the case, meter from the generator output terminal to ground.  If you show a good voltage (might be as high as 9 or 10v) then your generator is  fine.  Short across the cutout relay terminals momentarily and the ammeter should show a reasonable charge and the voltage observed at gen. output term. should be roughly the battery voltage.  If this is the case, replace cutout relay.

If, however, you see no appreciable voltage at the generator in the above test, things get more expensive.  Third brush generators typically don't lose their polarization but it's possible espeically if the fellow that jumped her with the wrong voltage also didn't know a thing about polarity (sorry, I'm a 6v purist.)  If that's the case, I recommend the motoring test: 

Motoring test -- remove generator from tractor and set on test bench.  Connect ground (POSITIVE for heaven's sake) to generator frame.  Connect 6v negative to gen. output terminal.  Be sure to brace generator well (a vise works nicely) as the whole point is to spin it like a motor.  If at all possible, put an ammeter in the circuit.  There are several possible outcomes -- 1)  Generator motors fast and evenly -- good generator.  2)  Gen. does not motor and ammeter goes off scale -- internal short, need to rebuild generator. 3) Gen does not motor and ammeter reads low or zero -- internal open or test connections bad.  Verify test connections, if still bad, rebuild generator.  (normally I'd say replace brushes and inspect for internal broken wires but in your case something may have melted.) 4)  Motors slow and unvenly with low current or "jumpy" meter reading -- dirty commutator, clean and retest.

Hope this helps,

Pete P.

My 9N is driving me nuts, maybe you fine folks can help.  Subject is a '40, begrudgingly converted to Pertronix electronic ignition but stubbornly still 6V pos. ground.  Since conversion she's been very reliable and maybe even a bit more powerful. 

Was plowing nicely for an hour or so when she started to missfire suddenly as if the spark were weak.  Nursed her back to the barn, found spark properly blue and strong on all cylinders but No. 3.  No. 3 was strong when it fired but it missed badly.  Replaced plugs, wires, cap, rotor, coil.  Inspected and cleaned battery connections, switch connections, Pertronix connections to ground and switch.  Just incase, inspected fuel system; found good delivery to carb & no improvement on choking.  No visible play in camshaft distributor end, no unusual wear on distributor or old cap.  Still no improvement at all.

Does anyone have experience with these Pertronix modules -- can they fail intermittently in only one position (one cylinder?)  If not the module, what am I overlooking? 

Thanks in advance,

Pete P.
Harborcreek, Penna.