ford 8n

I believe Yesterdays tractor co. offers  rebuild manuals for the 8n,   #2N-8n_SV  140 pages for $14.95 also  IT aftermarket shop manual 152 pages for $24.95  #FO-4   and a parts manual 228 pages for $19.95  #FO_9N2N8N_PT.  They also have a  dvd  that goes through a complete rebuild for the 9N , 2N and 8N. its # is JDV-01050 I bought a similar one to get familiar with my Ford 3000. Hope this helps 

There's a nice engine rebuild manual for the tractor on ebay for $32.99

Ben

http://www.circlegtractorparts.com

Amazon have some books at a good price.

If it has gotten hot, be sure to have that head magnafluxed to be sure there are no cracks, and have it checked for flatness.  As a side note, I have in my possession, an original 1948 8N Operators manual from the Ford Motor Company.  If you find you need any of the info from it let me know and I'll copy the approriate passages for you.  It contains quite a lot of information, not usually found in today's operators manuals.

I would think a rosebud would do the trick.

I would think a rosebud would do the trick.

Yep, a rosebud or a propane weed burner will do the job just fine.  Even a charcoal grill will get it done if nothing else is available.  Place the ring gear on a layer of firebrick and heat it as evenly as possible, being careful not to get it too hot – 400°F should be hot enough to force it over a cold center plate.  I'd have the center plate in the freezer until I was ready to assemble.

If you go above 400°F you will alter the heat treating of the gear ring, possibly softening it to the point of causing early tooth wear.  Your local welding supply house may sell TempilStiks, crayons that melt at specific temperatures for heat treating, if you don't have a pyrometer.

Also, check both the ring's and the center's edges for burrs and dress them off with a file before you  start.  A slight chamfer on the leading edge of the ring or the plate will make it easier to get it started, too – it only takes a few thousandths chamfer to do the job.

I have changed many starter rings in my life.  No I have never seen one that was properly installed spin.   I was a new starter ring correct?

I've never had to do that, David.  I did have one instance of a ring slipping on a flywheel, but I did not weld it for fear of crazing the flywheel face. 

What I did was to drill several holes through the flywheel/ring gear interface and perpendicular to the flywheel face.  The holes are centered exactly on teh shear line were the ring and flywheel meet.  I lightly chamfered the edges of theh holes and then cold-forged rivets in the holes.  After all the rivets were set, I went back with a cup grinder and stoned of any excess, leaving the rivets perfectly flush to the flywheel.  The rivets acted the same way a Woodruff key does in a shaft/sheave fit up.

The chamfering of the rivet holes makes a place for the rivet stock to expand into forming a very shallow “flat” head.  That is plenty sufficient to keep them from coming out of the holes accidentally 

Should the ring gear need to be removed later, It is easy enough to drill out the rivets since they are very low carbon steel and therefore soft.. 

It's not what I would have recommended.  But in for a penny, in for a pound, if you haven't warped the flywheel, you just might get away with it. 

I agree with Spring Valley Larry, although I've seen a few “almost loose” installations.

Congratulations,

Time will tell if it is now unbalanced by hammering out the rear main bearing and breaking the crankshaft at the harmonic balancer (that weird looking pulley on the front of the engine).

What is usually done in cases like yours is to, after the ring gear is installed, pour anaerobic compound around the interface of the two components, as this pretty much guarantees concentricity and reduces the risk of knocking out a starter pinion.

There are reasons ring gears are fitted that way and not bolted or tack-stitch welded.

And I completely agree with Bob.   A flywheel will have blind hole drillings into it which are strictly for balance. This is done to  remove even a fragment of weight.  A one OZ weld bead or anything else weighs a whole bunch at even 2000 RPM.   Simply stated the  engine balance will be totally hosed now.  

Although used with automobile automatics, ring gears are routinely stitch welded to the flexplates from the factory I have a picture of a stock pontiac v8 flexplate but I'm new to this posting picture uploading stuff . I would agree  the use of an anerobic would have been the first choice.

Does the engine shake at around 2000 rpm? when it didn't  before. that would pretty much prove that the engine is now out of balance, if not you did a very fine job of getting those welds perfectly sized and placed  and it may last as long as any new engine, but if there is obvious vibration now     a new flywheel/ring gear will be the best bet…

Like I said, time will tell.

David,

 Your buddy says “it aint no race engine”. I have built a few of those and so I dug out a few of my tables from back in the day.

An imbalance of one ounce 1” away from center of rotation at 2,000 rpm will be subjecting a force of 7 lbs. At 4,000 rpm, the force grows to 23.5 lbs! Double the speed again to 8,000 rpm and the force becomes 114 lbs Remember, this is one 1” away from the center of rotation. Now keep in mind that in the case of this tractor we are not talking about 1” away from the center of rotation. This is exactly why people that know what they are talking about panic.

 What's really going on here is that you do have welds perhaps close to evenly spaced and they are approximately the same size. It is out of balance it has to be. The fact that you can't feel it simply means that the vibration dampener is doing it's job. But it will only take so much for so long.

 Admittedly I am a stickler for doing things the right way and this repair does not follow that standard.

 Larry

Larry,

David and his “mechanic on the other side of town” probably never got past second grade, which I guess is okay because they have survived this long. But in the real world where ignorance is little tolerated, they would undoubtedly stumble. You are making them look like “deer in the headlights”. They don't want to hear that stuff. Ignorance is bliss.

Sure would be nice to be able to disagree, without being disagreeable.  Advice has been given and explained.  He is free to accept, ponder, or ignore.  Insults don't accomplish anything positive in the information exchange.  Your mileage may vary.