1951 Ford 8N Outer Hydraulic Lift Rockshaft Arm

[robertiford]

My lift arm snapped off and I need to replace it. I got the old one off but am unable to get the replacement to slip on the rockshaft. I ordered the standard replacement (9N543B) which has 37 splines, the same as the rockshaft, but it seems to have a wee bit smaller ID and the splines are not as deep as the rockshaft. I'm thinking there were two different types of rockshafts used during production of the 8Ns. Help please.

 

[wore out]

''I'm thinking there were two different types of rockshafts used during production of the 8Ns.''

I'm thinking you got a part from ''The Land of Almost Right''!

Oem part didn't change during the production run.

 

[Dean]

Agreed.

OP needs to buy a used OEM part.

 

[Kirk-NJ]

There was a change made in 1951 to the rock shaft arm. Its
more beefed up. You can see this on the top of the arm it was
more flat on top instead of oval. Dont know if splines were
effected. Usually when ford changed any part number they
added a letter at the end like the B at the end of the part
number you supplied. Check to see which arm you have. I might
have one if you need it. Email is open

 

[Kirk-NJ]

Im sorry change was made in 1952

 

[Dean]

No change to rock shafts but upper lift arms strengthened for 52 model year. No change to splines.

 

[robertiford]

Purchased a used one and it fit great. So much for the after market variety.

 

[BobW13]

(quoted from post at 23:01:42 03/03/23) Purchased a used one and it fit great. So much for the after market variety.

here did the aftermarket arm come from? For future reference.