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Shackle adjustment


Mertz

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I have read some of the threads on installing new shackle bushings and the manual on how to set them up. From the threads I understand that the front drivers side and the rear passenger side are left hand threads. The manual says to space the front shackles 3/4” from the frame and the back 7/8” from the frame. All mine are currently fairly tight to the frame except the rear passenger side which is about 5/8”. My question is since the bushings are threaded will they move over time and be forced inward?  Do I need to move them out or are they good the way they are and should I move the rear one in?

 

I see there is a Marcel Backs on this forum. My name is also Marcel. There aren’t many of us around. The manager of my NAPA store is also Marcel but goes by Marc. 

 

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The “Silent U” spring shackles are threaded their whole length and if they are worn enough to allow the distance to the frame to change then they are worn well past the point where they should be replaced. To adjust, you will have to unscrew the bushing, re-align things properly, then screw in the bushing. How hard this is depends on how frozen the bushing is in either the spring eye or the holder on the frame.

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After getting a better look I see that someone at one point welded the shackle to the support. I got the bottom bushing out but could not get a hold of the nut on the upper bushing.  It looks like it has been pulled through the frame. Also the mount has ovaled and the upper bushing is very loose. Going to need a new support bracket probably on both sides. A six point impact socket, breaker bar and a heavy foot got it loose. I think the truck has been overloaded. The side of the door has 8000 GW painted on it. Is grinding the rivets off the best way to go or should I try drilling them out?

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Rivets by nature expand when hit and get tighter in the hole. Grind the heads off, drill a small hole in the rivet to allow the rivet to expand into the hole you drilled, and drive them out. Worked for me.

 

 

 

 

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Agree with BobK, when I removed the various riveted parts to my frame I drilled a hole through the rivet, ground off the one side then used an air hammer to push the rivets back out.  Then I opened the holes slightly to use 7/16" hardware to fasten items back on(like the running board brackets).

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21 minutes ago, Mertz said:

I assume that you would use grade 8 hardware. 

 

I did use grade 8, almost exclusively in my on-going project.  Cost wise since I'm replacing all the hardware in the truck, Grade 5 vs. 8 didn't result in much difference, however I will say despite they should be the same(all grade 8), I've had very bad luck with big box store grade 8 hardware, therefore I buy most of my hardware from Fastenal.

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2 minutes ago, Lingle said:

 

I did use grade 8, almost exclusively in my on-going project.  Cost wise since I'm replacing all the hardware in the truck, Grade 5 vs. 8 didn't result in much difference, however I will say despite they should be the same(all grade 8), I've had very bad luck with big box store grade 8 hardware, therefore I buy most of my hardware from Fastenal.

 

I thought most automotive hardware was Grade 5 as 8 is more brittle?

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I have found that the hardware on my truck is much less susceptible to rounding and stripping. I believe I read somewhere that it is hardened steel. I am using all the original hardware I can on my truck for that reason. It also saves a lot of money and there is no confusion what will fit. I soak everything in citric acid clean it with a wire wheel and rebag it and spray it with WD40. It has taken a long time but heck what else is there to do when it’s to cold to work outside. 9E39F6C8-BFAF-4EE4-993E-679D9986266F.jpeg.a946f8033163d025a969f8e029bdafe8.jpeg

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Yes, I would think grade 8 would be correct. Make sure the bolt has a shoulder on it (non threaded portion under the head). You want that shoulder part of the bolt to fit snug in the hole, so be careful if you have to enlarge the hole to fit the bolt. As Lingle said in the above post. After everything is set and bolted tight, I would consider a few short beads of weld to keep the pieces from sliding around and enlarging the holes. There is a lot of stress on suspension parts as you go down the road, that's why the factory used rivets and not nuts and bolts to hold them together.  

 

I'm no expert...... feel free to correct me.

 

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Brittle? Never heard that...most automotive arguments are "is it ok" to use grade 5 instead of a grade 8. I've always used grade 8 on suspension stuff and grade 5 for less stressful stuff like brackets.

 

48D

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It is my impression that the steel used in the original rivets was relatively soft. Otherwise how could it have yielded properly when formed into a rivet? I agree that the shoulder of the bolt needs to be a snug fit in the hole to work properly in this application but am not so sure that a grade 5 or 8 is needed.

 

If you have access to a torch to heat the rivet and a way to get behind for holding a set, then riveting is not much more difficult than some other restoration procedures. At least consider it when putting the spring shackle back on. Way back when a spring repair shop used a cutting torch to remove one of the rear spring shackles on my car. When I had everything apart I filled in the damaged holes in the frame, re-drilled them, and finally riveted the shackle back in place (Bolted in for alignment, then replace bolts one at a time with rivets). That is the only time I ever attempted this type of task and while it took some effort and work it was not impossible for a newbie to pull off.

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When I replaced the ball joints on the QuadCab, the new ball joints were mechanically fastened with grade 5 bolts supplied.  Grade 8 bolts have a higher shear stress rating than grade 5s, and tho the QuadCab frame is 100k, the control arms sure felt and sounded like 50k.  The older Dodge frames more than likely have 36k, so going grade 5 on body attachments and grade 8 on suspension is good practice.  As the original rivets clamped and locked parts in place by expanding in mounting holes when set that were probably not concentric, replacement bolts are only clamping in mounting holes, with some space in the mounting holes for parts to move around.  To restrict this movement, more final torque must be applied to the bolts to generate enough clamping force equivalent to the original rivets clamping and locking force.

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When i had the box off the frame, i took the time to remove all the rivets and replace them with bolts. Knowing i have to go back into it at some point. In my 80 truck shop manual it described the process. Remove rivet and drill to next oversize and replace with grade 5 bolts. I used grade 8 as they resist corrosion better. 
when i built the lift for my 80, thats exactly what i did, 20 years ago, and i havent been kind to that truck. Its held up fine and nothing has moved. 

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Just a FYI: The Pilot-House Truck used rivets for the 48-49 frame attachments, then switched to bolts starting in 1950.

The early trucks 39-47 used rivets also, so I think of the mid to late 1950 truck as a  transitional year for the PH. 

 

Other stuff (not completely related to the thread, but related to the frame)

 

Things that changed in 1950 mid year was the floor shifter moving to a column shifter,  the king pin increased in size, and the steering box was changed to fit the new steering brace design.  

 

48D

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Got the one shackle bracket off. Ground off the head of the rivet and drilled the rivet until I could pound them out.  The rivets were harder than expected but once I figured out my technique with the grinder it wasn’t to bad. F0D7DBCB-F968-4ADD-B478-269E5CCB6D5D.jpeg.7f86ffb02643e926576b5822932aa4a7.jpeg

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