151AL dial ? & repair

[cvo]

The arrowed part in picture binds up. Phone dials but needs help rotating back to position.
I'm new and what I've read about repairing dials they can be tricky. I want to repair this myself.
Point me in the right direction? 
Thanks to this forum I was able to use my 302 as a subset for my 151.

[rdelius]

I think I see fine rust around the impulse cam shaft. What I have done if I think I do not want to make a major project is get some very light wight oil, place a drop on the screw slot.Tke a fine screwdriver and back the screw out several turns Back and forth untill the part moves freely.There is a "snubber" inside the dial that also might be out of adjustment
Robby

[cvo]

I think I see you comin' down to the hills of Tennesee cause I'm buyin your supper son!!!!!!!!!!!
That fixed it!
I think that parts called a "pawl", sure didn't want to get into the "snubber".
Having fun tomorrow putting the 302 & 151 together.
Thank you a bunch.