66 Clutch Rod and bell crank

[William G.]

I'm still trying to straighten out the little things on my new 66 roadster. The clutch rod in the car will either allow me to disengage the clutch fully or take pressure off the throwout bearing.... but not both at the same adjustment. Consequently my throwout bearing is audible at idle. I noticed that there are two different clutch rods in the Corvette Central book.The shorter one is listed as fitting a 67. So I ordered the longer 66 rod thinking that the problem was solved. Unfortunately, in order to install the longer rod the adjusting nuts are at the far end of their travel and it still doesn't function correctly. I have also noticed that there are two different bellcranks. With my luck I have the wrong one. Can someone tell me the difference between the two bell cranks and is that the probably source of my problem? As usual, thanks for any help.

[Joe L.]

Re: 66 Clutch Rod and bell crank

I'm still trying to straighten out the little things on my new 66 roadster. The clutch rod in the car will either allow me to disengage the clutch fully or take pressure off the throwout bearing.... but not both at the same adjustment. Consequently my throwout bearing is audible at idle. I noticed that there are two different clutch rods in the Corvette Central book.The shorter one is listed as fitting a 67. So I ordered the longer 66 rod thinking that the problem was solved. Unfortunately, in order to install the longer rod the adjusting nuts are at the far end of their travel and it still doesn't function correctly. I have also noticed that there are two different bellcranks. With my luck I have the wrong one. Can someone tell me the difference between the two bell cranks and is that the probably source of my problem? As usual, thanks for any help.

William-----

You didn't mention whether your car is a small block or big block and, in this case, it makes a difference. However, for the purpose of this question, I'm going to assume that you have a small block.

The difference between the 1963-E1966 small block lever assembly (bellcrank) is about 23 degrees difference in the angularity between the position of the arms on the shaft. 1963-E66 small block had about 135 degrees between arms; all (big block and small block) L66-81 have about 158 degrees of angularity between arms. I don't know exactly when the changeover occurred for 1966 but I believe it was fairly early in the model year. This creates a lot of confusion. To make matters worse, no part numbers will be found on the lever assemblies.

In any event, the clutch fork pushrod is specific to which lever assembly is on the car. The early lever assembly uses the GM #3844209 rod which is 10-9/16" in overall length. The later lever assembly uses the GM #3872960 rod which is 8-37/64" in overall length.

In addition, the pedal pushrod is different for the two clutch linkage set-ups. The 63-E66 small block used pedal pushrod GM #3819154 pushrod which is 18" overall length. The L66-81 used pushrod GM #3888213 which is 19-3/16" overall length. The GM #3888213 rod can be used for 63-E66, but the 3819154 cannot be used for L66-81.

So, you need to make sure that you have the right combination of parts.

[William G.]

Re: 66 Clutch Rod and bell crank

Joe, thanks for clarifying the subject so well. Now that I know that there are three parts involved I can figure out what I have and what I need to get.