French locks
Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
French locks
I posted over in C3 about this maybe someone here knows? Can French locks be replaced with lock washers? Why were they used to begin with, and Loctite was recommended to use instead of the french locks, is this ok?
I have them installed but the "corners" of the locks are ripped. Anyone have a trick to installing these without ripping them? I used never-sieze and brought them up even but as soon as I got to about 50 ft/lbs they start to twist as the bolt head clamps down.
Thank you,
Gary
I have them installed but the "corners" of the locks are ripped. Anyone have a trick to installing these without ripping them? I used never-sieze and brought them up even but as soon as I got to about 50 ft/lbs they start to twist as the bolt head clamps down.
Thank you,
Gary
Racer
Joined: Mar 2001
Posts: 438
Likes: 0
From: Houston, Texas
Re: French locks (gtr1999)
Gary, I didn't have that problem. The stayed put as I tourqued things up. You have a good question.. what ~would~ be the advantage of the Franch locks over a lock washer. The only thing I can think of is that the washer wold be to thick and not allow the bolt threads to totally engage.
Pro
Joined: Aug 2001
Posts: 605
Likes: 1
From: Hernando Beach Fl
Re: French locks (noskillz)
Can French locks be replaced with lock washers?
Yes but lock washers are not a positive lock and can loosen.
Why were they used to begin with,
They provide an absolute lock than no other method car when the "ears" have been bent only unbending or rust will allow them to loosen.
and Loctite was recommended to use instead of the French locks, is this ok?
Not really an alternative to French locks especially in areas where heat is a factor, i.e. exhaust manifolds.
I do not have torque specs handy although I should know them by now, I believe you are overtorquing the fasteners past the French locks shear capacity.
jer
Yes but lock washers are not a positive lock and can loosen.
Why were they used to begin with,
They provide an absolute lock than no other method car when the "ears" have been bent only unbending or rust will allow them to loosen.
and Loctite was recommended to use instead of the French locks, is this ok?
Not really an alternative to French locks especially in areas where heat is a factor, i.e. exhaust manifolds.
I do not have torque specs handy although I should know them by now, I believe you are overtorquing the fasteners past the French locks shear capacity.
jer
Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
Re: French locks (3X2-427)
Thanks Jerry for the reply. I too, didn't like the lock washer or loctite option.
I think the original type of bolt will work better then the threaded bolts I used to replace the rusted originals. The torque spec in my Gm manual and a couple of other books said 70-90 ft/lbs. I agree that the torque was twisting them off past 60 ft/lbs so what spec should I use?
Thanks,
Gary
I think the original type of bolt will work better then the threaded bolts I used to replace the rusted originals. The torque spec in my Gm manual and a couple of other books said 70-90 ft/lbs. I agree that the torque was twisting them off past 60 ft/lbs so what spec should I use?
Thanks,
Gary
Drifting
Joined: Jun 2000
Posts: 1,596
Likes: 52
From: Southern NJ
C2 of Year Finalist (stock) 2019
Re: French locks (gtr1999)
gtr1999
I dont know what the exhaust manifold torque specs are for the 69 however they are only 20 ft lbs for a 66 BB and the french locks are only used on the two ends not the middle. 50 ft lbs seems way too high -- the intake manifold is only 30 ft lbs.
john lolli
I dont know what the exhaust manifold torque specs are for the 69 however they are only 20 ft lbs for a 66 BB and the french locks are only used on the two ends not the middle. 50 ft lbs seems way too high -- the intake manifold is only 30 ft lbs.
john lolli
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Thread Starter
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
Re: French locks (JL66REDCPE)
John
No problem,thats why we're here,to help each other out.
I have them on, but I don't really like them and I was shooting for 70-75 ft/lbs. When ever I get the car on the ground again I'll check them from time to time and change over to the ss locks if they loosen.
Thanks again for the input guys.
Gary
No problem,thats why we're here,to help each other out.
I have them on, but I don't really like them and I was shooting for 70-75 ft/lbs. When ever I get the car on the ground again I'll check them from time to time and change over to the ss locks if they loosen.
Thanks again for the input guys.
Gary
