In Reply to: 8n hydraulic cover/seat mount location posted by Doug on January 29, 2020 at 15:26:36:
The OEM Ford 8N seat spring, p/n 9N-400-C, is fastened using two 7/16" studs (#883836-S8), 2 lockwashers (351436-S8), and 2 hex nuts, 7/16-20 (#33792-S8), not bolts, however a previous owner may have swapped them out for hex bolts. You may or may not know that studs are engineered with the same major size but each end has a different thread pitch, one coarse and one fine. Cast iron requires thread sizes to be coarse -it's the nature of the beast. The end that accepts the hex nut fastener is always the fine thread. The stud used is 7/16"-14 and 7/16"-20 x 1-3/8" L. It would depend on how much of the broken stud or bolt you are working with. Have you tried an Easy-Out? I, too, do not think you should try and drill out the hole unless you have the proper tools. You arenít going to get it using a hand drill. If the drill walks, it will cause the broken stud to encroach into the base thread and you could end up with more of a mess. A good magnetic base drill unit would be best and a carbide drill bit and an experienced machine shop would be a good place to have that done if you need it drilled out. Worse case is to have it repaired at a professional shop and if need be insert a Heli-Coil. If you get the broken stud out, donít drill it out Ėonly chase a tap to clean up the 7/16-14 threads. Look first to see if it is a blind hole. You donít want to bottom out the tap and break it.
FORD N-SERIES TRACTOR HYDRAULIC LIFT TOP COVER: