The Ford Barn

Dave Mellor NJ · 03-19-2025, 12:51 AM

This happened to me a few years ago and i know of about 4 others, You can't release the clutch. I got it off and got a foreign replacement from Brattons it was slightly small. Trying to beat it on it ruined the fork. I got an original,pulled the rear, trans,and bell, drove the shaft out and removed the bad one, reassembled the fork and original arm with pins,put the trans and rear back and swore not to buy any more foreign crap

TomInCologne · 03-19-2025, 05:50 AM

Quote:

Originally Posted by Dave Mellor NJ

This happened to me a few years ago and i know of about 4 others, You can't release the clutch. I got it off and got a foreign replacement from Brattons it was slightly small. Trying to beat it on it ruined the fork. I got an original,pulled the rear, trans,and bell, drove the shaft out and removed the bad one, reassembled the fork and original arm with pins,put the trans and rear back and swore not to buy any more foreign crap

I had the same problem, cracking the arm. Obviously my feet are too heavy.
But don't blame this on 'foreign crap', this arm was a bad engineering from Henrys men...

Y-Blockhead · 03-19-2025, 07:18 AM

Quote:

Originally Posted by Dave Mellor NJ

This happened to me a few years ago and i know of about 4 others, You can't release the clutch. I got it off and got a foreign replacement from Brattons it was slightly small. Trying to beat it on it ruined the fork. I got an original,pulled the rear, trans,and bell, drove the shaft out and removed the bad one, reassembled the fork and original arm with pins,put the trans and rear back and swore not to buy any more foreign crap

I think the problem arrised from you “bearing” it on.

nkaminar · 03-19-2025, 07:41 AM

I agree with Tom on this. The original design has a smaller pin and when that was increased in diameter the arms started cracking. I carry a spare arm. I wonder if a heavy duty hose clamp or two would prevent the arm from cracking.

Marshall V. Daut · 03-19-2025, 09:14 AM

Besides being of questionable design, after almost 100 years of use, we are seeing more and more cases of this arm failing due to metal fatigue these days. I have replaced three in the last year alone! Old-timers in the hobby can attest that this wasn't a major problem 20-25 years ago and has increased in frequency since then. The new repo arm is much stronger, although the staking pin area will always be the Achilles heel. Too bad that you'll probably have to replace the new arm again in another hundred years.

M.

Kurt in NJ · 03-19-2025, 11:37 AM

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If it was a design problem there would have been a service bulletin.
If it was a common problem when the cars were less than 10 years old Pep Boys and other aftermarket parts catalogs would have them advertised.
Yes to have them start failing after 75 years is a design failure— they were made too good.

jb-ob · 03-19-2025, 02:35 PM

Replace it with an original '28 version for more leverage................

JayJay · 03-19-2025, 06:54 PM

There used to be a billet steel version of the clutch arm available, but I don't see it now. I think I may have one laying around somewhere...

Richard Knight · 03-19-2025, 07:16 PM

I think some of the failures nowadays may be related to the modern pressure plates with springs that are too strong, out of spec.

Vic in E-TN · 03-19-2025, 09:01 PM

This happened to me approx 30 years ago. The replacement had a bigger round part and worked well. It looked like a forging, not a casting. I do not remember where i got it.

Vic

alexiskai · 03-19-2025, 10:04 PM

There are two versions of the A-7511 clutch release shaft arm being sold currently. One is a replica of the original, while the other uses significantly more material. Both claim to be US-made.

Tom Endy wrote an article in which he speculates that some instances of broken clutch arms may be due to an erroneous service bulletin that recommended modifying A-7511-B arms to accommodate a larger pin, while the A-7515-B fork would need to be replaced as it could not be safely adapted. He hypothesized that this advice was reversed from what the engineers intended – that the fork be modified and the arm replaced.

Y-Blockhead · 03-19-2025, 10:15 PM

The second one alexiskai shows is longer than the original to make it easier to disingage the clutch. I have been using those for years, no problen, no fit problem either.

Ford eliminated the woodrof key when they went to the larger pin on both the fork and arm (Service Bulletins page 351).

oldspert · 03-19-2025, 10:43 PM

Quote:

Originally Posted by Y-Blockhead

The second one alexiskai shows is longer than the original to make it easier to disingage the clutch.

The longer arm would also require more force at the pedal end to release the clutch. Which would be worse, more force at the pedal or less force at the clutch?
Ed

Y-Blockhead · 03-20-2025, 01:03 AM

Quote:

Originally Posted by oldspert

The longer arm would also require more force at the pedal end to release the clutch. Which would be worse, more force at the pedal or less force at the clutch?
Ed

You are wrong. Longer arm makes it easier at the pedal.

oldspert · 03-20-2025, 09:05 AM

Quote:

Originally Posted by Y-Blockhead

You are wrong. Longer arm makes it easier at the pedal.

You are right , what I meant was longer stroke at the pedal. Thanks for reminding me of my mechanical engineer training. After all I am 80 turning 81 in a couple months.
Ed

TomInCologne · 03-20-2025, 10:11 AM

Quote:

Originally Posted by Y-Blockhead

You are wrong. Longer arm makes it easier at the pedal.

...but the longer arm makes it easier to crack it... ;-)

JayJay · 03-20-2025, 10:18 AM

Quote:

Originally Posted by TomInCologne

...but the longer arm makes it easier to crack it... ;-)

The force applied at the shaft is determined by the resistance from the pressure plate springs. If the shaft did not turn then yes, the force applied would be higher with the longer arm (assuming this same push by the leg), but since the shaft does rotate, no the longer arm would not make the bracket more prone to breakage.

TomInCologne · 03-20-2025, 11:20 AM

Quote:

Originally Posted by JayJay

The force applied at the shaft is determined by the resistance from the pressure plate springs. If the shaft did not turn then yes, the force applied would be higher with the longer arm (assuming this same push by the leg), but since the shaft does rotate, no the longer arm would not make the bracket more prone to breakage.

and then, when the clutch is totally released, your foot works against the stop. with a longer lever. Don't ask me how i know, explaining it will be embarrassing for me.

Edit: only true if the 'stop' is within the clutch and not within the pedal mechanism...

Y-Blockhead · 03-20-2025, 11:56 AM

Quote:

Originally Posted by oldspert

You are right , what I meant was longer stroke at the pedal. Thanks for reminding me of my mechanical engineer training. After all I am 80 turning 81 in a couple months.
Ed

Happy Birthday Ed!!

Y-Blockhead · 03-20-2025, 12:06 PM

Quote:

Originally Posted by TomInCologne

...but the longer arm makes it easier to crack it... ;-)

Me thinks it would be pretty hard to crack one of these bad boys.

Although I did break my original one!!

03-19-2025, 07:41 AM	#4
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 5,854	Re: Clutch release arm crack I agree with Tom on this. The original design has a smaller pin and when that was increased in diameter the arms started cracking. I carry a spare arm. I wonder if a heavy duty hose clamp or two would prevent the arm from cracking. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

03-19-2025, 09:14 AM	#5
Marshall V. Daut Senior Member Join Date: Apr 2011 Location: Davenport, Iowa Posts: 2,626	Re: Clutch release arm crack Besides being of questionable design, after almost 100 years of use, we are seeing more and more cases of this arm failing due to metal fatigue these days. I have replaced three in the last year alone! Old-timers in the hobby can attest that this wasn't a major problem 20-25 years ago and has increased in frequency since then. The new repo arm is much stronger, although the staking pin area will always be the Achilles heel. Too bad that you'll probably have to replace the new arm again in another hundred years. M.

03-19-2025, 11:37 AM	#6
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,553	Re: Clutch release arm crack Sponsored Links (Register now to hide all advertisements) If it was a design problem there would have been a service bulletin. If it was a common problem when the cars were less than 10 years old Pep Boys and other aftermarket parts catalogs would have them advertised. Yes to have them start failing after 75 years is a design failure— they were made too good.

03-19-2025, 02:35 PM	#7
jb-ob Senior Member Join Date: Jun 2010 Posts: 787	Re: Clutch release arm crack Replace it with an original '28 version for more leverage................

03-19-2025, 06:54 PM	#8
JayJay Senior Member Join Date: Jan 2020 Location: SF Bay Area Posts: 2,104	Re: Clutch release arm crack There used to be a billet steel version of the clutch arm available, but I don't see it now. I think I may have one laying around somewhere... __________________ JayJay San Francisco Bay Area ------------------------ 1930 Murray Town Sedan 1931 Briggs S/W Town Sedan It isn't a defect, it's a feature!

03-19-2025, 07:16 PM	#9
Richard Knight Senior Member Join Date: Mar 2021 Posts: 243	Re: Clutch release arm crack I think some of the failures nowadays may be related to the modern pressure plates with springs that are too strong, out of spec.

03-19-2025, 09:01 PM	#10
Vic in E-TN Senior Member Join Date: May 2010 Location: Maryville, TN Posts: 531	Re: Clutch release arm crack This happened to me approx 30 years ago. The replacement had a bigger round part and worked well. It looked like a forging, not a casting. I do not remember where i got it. Vic

03-19-2025, 10:04 PM	#11
alexiskai Senior Member Join Date: Apr 2018 Location: Mebane NC Posts: 2,848	Re: Clutch release arm crack There are two versions of the A-7511 clutch release shaft arm being sold currently. One is a replica of the original, while the other uses significantly more material. Both claim to be US-made. Tom Endy wrote an article in which he speculates that some instances of broken clutch arms may be due to an erroneous service bulletin that recommended modifying A-7511-B arms to accommodate a larger pin, while the A-7515-B fork would need to be replaced as it could not be safely adapted. He hypothesized that this advice was reversed from what the engineers intended – that the fork be modified and the arm replaced.

03-19-2025, 10:15 PM	#12
Y-Blockhead Senior Member Join Date: Jul 2011 Location: Redondo Beach, CA Posts: 6,641	Re: Clutch release arm crack The second one alexiskai shows is longer than the original to make it easier to disingage the clutch. I have been using those for years, no problen, no fit problem either. Ford eliminated the woodrof key when they went to the larger pin on both the fork and arm (Service Bulletins page 351). Last edited by Y-Blockhead; 03-19-2025 at 10:23 PM.