Allis Chalmers D17 - Fuel Tank Studs

[trevor68]

Anyone happen to know what size and thread the two nuts would be to secure the fuel tank using the pre-installed studs on the bottom of the fuel tank? It is only held by the straps currently and I would like to pickup the correct nuts to secure using the studs also. Without removing the tank the studs are difficult to see.

 

[DrAllis]

Is this an older series D-17?? You say "straps", which to me means more than one (cross) strap. Tractors before chassis s/n 24001 never had the strap that goes from the steering column forward to the battery area. Many of them got updated to that extra strap improvement and you can tell because the strap is retained to the steering column by a U-bolt muffler clamp.The reason they settled in on TWO straps was because the fuel tanks were cracking using just one cross strap and those two studs you are referring to. The cracks were at those studs !! and the tanks had to be replaced. So, if it was mine I'd leave it as-is. If you insist on nuts, use rubber washers with flat washers to isolate the tank and use "nylock" plastic lock nuts. Tighten the nuts just snug and no more. The nylock plastic lock nuts won't vibrate loose when left snug. The nuts are 3/8" NC I think.