Hi, I have a 67 Chevelle and am having problems converting it to a 4 speed. I am going with machanical linkage currently and cannot get the clutch to disengage If I went to a Hydraulic system what would I need to do, or what parts would I need to get? Any help would be greatly appreciated.

Thanks,
Rocky

Hi, I have a 67 Chevelle and am having problems converting it to a 4 speed. I am going with machanical linkage currently and cannot get the clutch to disengage If I went to a Hydraulic system what would I need to do, or what parts would I need to get? Any help would be greatly appreciated.

Thanks,
Rocky

Thousands ...perhaps hundreds of thousands of Chevelles run every day with mechanical clutch linkage. If you cannot get it to work you have some incorrect parts in the mix. Going to a hydraulic system introduces a new set of variables...bleeding the system, pedal throw and the amount of travel of the bearing (you blow TO bearing seals if you have too much extension) to name a few.

IMHO...work on fixing the mechanical linkage. Introducing the hydraulics sends you down another rabbit hole. You need to determine what parts you need in there and what parts you have in there. Making this work is no big deal if you get the right parts. Heading off into hydraulic linkage land could leave you right where you are as far as clutch problems. Different problems but problems none the less. Hydraulic systems are not "plug and play" !

Better to fix what you have.

Thanks for the input and I guess you are right to stick with the machanical linkage. Unfortunately I have done just about everything I can to try and get it to work with no luck. I agree there is something in the linkage that is not right but I am not sure what at this point. I have pulled the tranny out twice so far, tryed different throwout bearings and always end up in the same place. I even changed the bellhousing from a scatter sheid to a original 621 bell... Question, are there different size clutch forks, that is the only part I haven't changed...

Thanks again for your help and would appreciate any more help you can give...

Rocky

Thanks for the input and I guess you are right to stick with the machanical linkage. Unfortunately I have done just about everything I can to try and get it to work with no luck. I agree there is something in the linkage that is not right but I am not sure what at this point. I have pulled the tranny out twice so far, tryed different throwout bearings and always end up in the same place. I even changed the bellhousing from a scatter sheid to a original 621 bell... Question, are there different size clutch forks, that is the only part I haven't changed...

Thanks again for your help and would appreciate any more help you can give...

Rocky

The forks are different, there are a least two different length Pivot studs in the bellhousing. You might ave the wrong rods or one wrong rod. Also you don't mention what scatter shield you had. If you had one with a block plate that changes everything all over again. The block plate moves everything back from the engine and changes the clutch linkage geometry. Switching out the bellhousing (and thereby removing the block plate) can change measurements also. Also the flywheel thiickness comes into play. If the flywheel has been surfaced enough you change dimensions.

You are experiencing "shoting at a moving target from a moving location with no site on you gun". You have to get some known dimensions down from the get go.

What pivot is in there?
What fork is in there?
What bearing is in there?
Leave the 621 in there becaue it is a KNOW item.
How thick is the flywheel?
Get the correct rods.

As an example .125 on the block plate is enough to mess things up. Any variation in ANY component in the above list can be additive to the problem. Some mismatches of parts can cancel other mismatched (incorrect) parts . The forks are about 1/2 inch different in length. 1/2 is HUGE as far as getting the linkage to work right. H-U-G-E !!!! You can cycle around on this forever until you stop and get control of what parts you have in the car..

Going hydraulic is not any easier than the stock linkage. You end up with the same critical dimensions just different components effecting those critical dimensions. Yes the linkage arms go away but you throw in the variable of the amount of travel in the bearing you buy. You add in the need to PRECISELY space the clearance between the bearing and the clutch fingers with the clutch disengaged. . All the issues related to a scatter sheild and a block plate remain. Travel issues in the clutch master cyliner come into play, presure at the master cylinder has to be tailored to the bearing in question. You most likely need a pedal stop to prevent over extension of the bearing and consequent blowing out of the seals in the bearing. I hope you see what I am tryng to say here...the hydraulic is not a quick fix.

You have to go back to square one and figure out what you have in that mechanical linkage and what you need to make it work. You gotta lock down EACH piece in that linkage chaing (all the parts listed above are part of that chain) ) and determine if each one is right. You gotta get KNOWN dimensions on the parts that are in there and compare them with the dimensions that are called out for the correct parts.

That is all I can give you. Good luck.