67 656 transmission (geared)

[Pete656]

I have a knocking in the gear case, left side,right where the step bolts on. Quiet at first,louder when warmed up. I've never taken the top off before. Any and all tips appreciated. I've got all winter to work on it.
Also what is this spring loaded lever with wires ?

 

[muleman51]

Isn't a 656 trans basically the same as a 560, could that be a start safety switch.

 

[flying belgian]

Is the sprong a return spring for the
clutch?

 

[used red MN]

Hello Pete welcome to YT! I believe the only thing with
a switch like that is the clutch safety switch. Been a
while since I have seen a 656 so that is all I can think
of. It may be mounted in the wrong location. You will have to open the cover on the back there is
a pressure oiling system under the rear cover that will
require you to disconnect a hose or two through the
hole. See link. If you are not aware of the online parts
catalog to view all the parts sections click the ..656
Farmall Tractor.. to the right of the ..Home.. icon. You
should get a I&T repair manual, see 2nd link.
CNHI Farmall 656 parts catalog

YT IH 656 manuals