manifold nuts

[Jim N.W.Mi]

Hi all,
Replacing manifold on my 8N. When removing the old manifold there was flat washers behing two nuts,a split lock washer behind one and no washer behind one. When I install new manifold should I use flat washers or no washers at all. I know to tourque to 27#. Thanks in advance for your help.

 

[Dell (WA)]

Jim.........according to my N-Ford MPC (master parts catalog) the N-exhaust manifold is held on with p/n: 351436-S7, 7/16 lockwasher; and of course the p/n: 33816-S, 7/16-20 BRASS hexnut torqued to 27ft/lbs........Dell

 

[Randy(PA)]

The 351436-S7 lock washer is an interesting beast. It looks like a standard helical spring steel lock washer, .446/.464 I.D. and .784 max OD, .109 nominal thickness, but it had the snagging corners (what would tear up the brass nut on removal) ground off 3/32 back from the ends at the split. I have never seen this on a Ford lock washer drawing or in a fastener standard before, but looks like a great idea to me.

 

[Bob Harvey]

I think the idea was to replace the (soft brass) nuts at every change.