The Ford Barn

Jeff M · 09-11-2012, 03:09 PM

Does anyone know what the correct size of the perch bolts are? I'm looking to clean up/straighten the threads and need to know what size die to buy.

Thanks

Randy in ca · 09-11-2012, 05:50 PM

I believe the thread for the spring perch bolts is 5/8 - 18

Jeff M · 09-12-2012, 08:23 AM

Thanks!

Kurt in NJ · 09-12-2012, 08:34 AM

It's the same size as the rear axle threads ---if you know of a axle rethreader to use, this tool opens up and clamps on the good threads, is then screwed off making the threads match the pitch of the good threads, if you just run a die down from the damaged end you can make new threads that won't match the remaining threads, the other tool that can be used to save a mushroomed first few threads is a thread file---
http://shop.advanceautoparts.com/web...ci_kw={keyword}
starting with the file 1/2 in good threads you work out to the end, this will give you a starting point for the die to give a good start to match the original threads.

Kevin in NJ · 09-12-2012, 11:29 AM

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Some of the threads are tighter tolerance threads and running a common die on them will make them loose and reduce the surface area which reduces the clamping force.

I now use thread files unless I am sure the threads are common tolerance. I hand pick the nuts clean.

This may all sound like I am going overboard, but Ford was very clever in using odd standards for a reason. I do not want to undo his fine engineering.

09-11-2012, 03:09 PM	#1
Jeff M Senior Member Join Date: Nov 2011 Location: CA Posts: 104	Perch bolt size Does anyone know what the correct size of the perch bolts are? I'm looking to clean up/straighten the threads and need to know what size die to buy. Thanks

09-11-2012, 05:50 PM	#2
Randy in ca Senior Member Join Date: May 2010 Posts: 1,640	Re: Perch bolt size I believe the thread for the spring perch bolts is 5/8 - 18

09-12-2012, 08:23 AM	#3
Jeff M Senior Member Join Date: Nov 2011 Location: CA Posts: 104	Re: Perch bolt size Thanks!

09-12-2012, 08:34 AM	#4
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,156	Re: Perch bolt size It's the same size as the rear axle threads ---if you know of a axle rethreader to use, this tool opens up and clamps on the good threads, is then screwed off making the threads match the pitch of the good threads, if you just run a die down from the damaged end you can make new threads that won't match the remaining threads, the other tool that can be used to save a mushroomed first few threads is a thread file--- http://shop.advanceautoparts.com/web...ci_kw={keyword} starting with the file 1/2 in good threads you work out to the end, this will give you a starting point for the die to give a good start to match the original threads.

09-12-2012, 11:29 AM	#5
Kevin in NJ Senior Member Join Date: May 2010 Location: South East NJ Posts: 3,398	Re: Perch bolt size Sponsored Links (Register now to hide all advertisements) Some of the threads are tighter tolerance threads and running a common die on them will make them loose and reduce the surface area which reduces the clamping force. I now use thread files unless I am sure the threads are common tolerance. I hand pick the nuts clean. This may all sound like I am going overboard, but Ford was very clever in using odd standards for a reason. I do not want to undo his fine engineering.