C2 Idler Pulley Mounting

[Larry M.]

For a 64 SHP/FI, the way I read the AIM there is no lock washer under the adjusting stud for the idler pulley. They would be removing a bolt from the water pump which would have a lock. Should that lock be kept under the stud? Also, the lower mounting bolt is a 122126. Can anyone tell me how long that should be?

[Joe L.]

Re: C2 Idler Pulley Mounting

For a 64 SHP/FI, the way I read the AIM there is no lock washer under the adjusting stud for the idler pulley. They would be removing a bolt from the water pump which would have a lock. Should that lock be kept under the stud? Also, the lower mounting bolt is a 122126. Can anyone tell me how long that should be?

Larry-----


Waterpump retaining bolts use no lockwashers between the bolt head and pump body. So, the stud which replaces one of the bolts for the idler pulley does not use one, either.

I don't have specs on the GM #122126 bolt.

[Larry M.]

Re: C2 Idler Pulley Mounting

Joe- thank you. After my post I found in the archives that the stud had no lock but did not know about the others. My car had locks but pics on the forum do not show them although one car does show them, owned by a meticulous guy....I was surprised.

The AIM does show a lock when you replace the bolt for the alternator brace.

[Dan H.]

Re: C2 Idler Pulley Mounting

Hi Larry, correct on the alt brace LW. It was already installed under a bolt and was painted chevy orange, but received a new longer bolt at St Louis, which will be natural unpainted.

[Joe L.]

Re: C2 Idler Pulley Mounting

Joe- thank you. After my post I found in the archives that the stud had no lock but did not know about the others. My car had locks but pics on the forum do not show them although one car does show them, owned by a meticulous guy....I was surprised.

The AIM does show a lock when you replace the bolt for the alternator brace.

Larry------


I've never seen a lockwasher on a waterpump bolt installed between the bolt head and the pump. When an alternator or other brace is installed on a stud or bolt also retaining the waterpump, that's different. There is virtually always a lockwasher installed between the bolt head or nut and the bracket.

[Larry M.]

Re: C2 Idler Pulley Mounting

Joe - what you say makes perfect sense to me. This would lead you to believe that the AIM would call for both a new longer bolt and a lock washer by part number for the brace....pull the old bolt and toss it. But the AIM actually has a note as Dan says above to use the existing lock. So this implies that engine assembly would put a lock on the upper right bolt only....I guess to make it easy for the poor guys in St. Louis.
Or more likely a mistake and St. Louis had to supply the lock contrary to the AIM. Don't know that it matters anymore as long as we put the lock on the brace bolt.