Ford 8N TractorDear Ole Mechanic;

I brought a 8N Ford tractor a short while back to use for mowing around our ten-acre patch of the Hill Country.  It came with a three-point mounted rotary mower that many folks around here call a shredder.  It runs fine and I had the blades sharpened so it mows good when there is enough rain to make things grow.  I have sort of figured out the three-point hookup, but there are two things that I have problems with.

The first is the steering.  It is so loose that I can turn the steering wheel almost a half a turn before the front wheels even think about turning.  I suspect the steering gear is loose, as there is not any play in the steering joints that I can see nor is there any excess play in the front wheels when I shake them.

The second problem involves the shredder.  When I step on the clutch while mowing, the tractor keeps on moving until the mower stops turning.  I have already run through a fence, so I am very careful to make sure that I don’t aim at something where I would need to stop quickly.

Can you help with either of these problems?

Mowing into Things
 

Dear Mowing;

Yes, I think I can offer some suggestion,s as I do love the old tractors.  I am going to cover your second problem first, as there is a quick solution for it.  A little mechanical background will help you understand what is causing your problem.  The PTO (Power Take Off) on your 8N is powered off of the transmission.  The clutch disconnects the engine from the transmission; however, the transmission does NOT disconnect from the rear wheels or the PTO.  Consequently, the shredder acts like a big flywheel and puts power back into the transmission and drives the rear wheels until the mower stops turning. The solution to the problem is a one-way or over-running clutch between the PTO and the PTO driveshaft to the shredder.  Most tractor parts stores and many older auto parts stores here in the Hill Country carry the over running clutches in stock.  Notice that I said clutches--plura,l as in several.  There are several different PTO and PTO driveshaft spline sizes, so there will be several similar appearing clutches that won’t fit your 8N.  You will need to know what size your PTO and your shredder PTO shaft splines are.  The 8N started life with a 1 1/8 inch (outside diameter) spline but there are also  1 3/8 inch spline replacement PTO shafts available.  You will need to do some measuring to make sure that you get the right size before you buy your over-running clutch.  Once the over-running clutch is installed between the PTO and the mower’s PTO drive shaft, the PTO can power the shredder but the shredder cannot power the transmission and rear wheels because the clutch will slip--sometimes with a clicking sound, depending upon the clutch’s design.

Now for problem number one--the loose steering.  It is probably due to wear in the steering gear box itself, because Ford did not install a grease zerk fitting to lubricate the steering box.  They installed a slotted plug so that gear oil could be added on the early 8N’s.  The old-style slotted plug is on the right side about six inches above where the right steering arm comes out of the box.  This plug was never mentioned in any of the manuals that I have seen, so many were never lubricated.  Later 8N steering boxes were packed with gear oil and until recently, I was never able to find a lube access point on them.  There is a very small pipe plug on top of the gear box.  You may need to remove the tool box to even see it, but at this point don’t try to use gear lube as it will just run out along side of the steering shafts due to wear.  Put a grease zerk in place of the plug and pump about a half a tube of grease into it.  There were two different steering boxes used in the 8N.  What you will need to find is an original Ford Operator's Manual (not likely) or get an IT Shop Service® Manual at your local tractor parts or auto-parts store (readily available for about $25).  It will give you the serial-number breakpoint between the old style and the newer style steering boxes.  It will also show nice pictures of both steering gear boxes but will not show where to put in the lubrication oil or grease.  If you decide to replace worn steering gear parts, they are available from some parts houses or several mail-order companies like Valu-Bilt® and Dennis Carpenter®.

My answer to your loose steering problem is a cop out but remember that you didn’t tell me what year your tractor is!  You can determine the year of your tractor with the IT® Manual and the serial number of your tractor.  The number is on a raised boss on the left side of the engine above and just to the rear of the engine-oil fill-tube.

Good luck and happy shredding.

Herr Professor Nuzanbolts