Crown Vic ifs install question

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RustNdust65
Posts: 67
Joined: March 3, 2016, 12:53 pm
Location: St. Louis, MO
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Crown Vic ifs install question

Post by RustNdust65 »

Hey everyone. So to keep it short and simple I'm most of they way through installing the ifs but I have run into one little snag. For those that have done this, when you get ready to weld up the brackets to the frame for the trailing arm bushings what is the proper distance between them? I've looked high and low for this and only got one measurement and wanted to hear what everyone else did. I've already cut and spun the bushings then welded it back together to make the slot horizontal instead of diagonal.

The most sound advice I've received so far is to bolt in the suspension, set the bushings nice and flat and just eyeball it straight. I guess when it gets aligned they can dial it in from there??

Any help would be greatly appreciated.

Thanks everyone
mercuryv8
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Joined: November 8, 2013, 1:20 am
Location: Edmonton, Alberta
Canada

Re: Crown Vic ifs install question

Post by mercuryv8 »

Good question.

Especially for me because I'm in the exact same spot on my install.

Nic
SLICKCOLLECTOR
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Joined: January 26, 2007, 8:04 pm
Location: eudora ks
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Re: Crown Vic ifs install question

Post by SLICKCOLLECTOR »

i have done 5 of these installations and have never cut and welded any bushings. the brackets fit the frame just right regarding width but the back of the bushing meets the frame leaving a gap at the front from the bushing to the frame. a couple of 3/8 inch wedges seal that gap and then tack weld your bushing. for a mounting plate for the bushing i use 1/4 inch plate and cut a pattern to match the bottom of the bushing. the mounting plate is welded on the frame with wedges with the bushing bolted to the plate. tack weld this setup to the frame, remove the bushing, then weld the mounting bracket to the frame. every time i have done this i had to reinforce my welds after i drove the truck a little. apparently there is a lot of force on this weld. the wedges were the secret for me. i don't weld the brackets with the bushing attached as it will melt the rubber if you do a good job welding the bracket and you do need the heat to attach this to the frame. i could not do this with out a lift however.

jim
1966 F100 SW 428CJ C6
1965 F100 SW 428 TL sold
1966 F100 SW CVC 428CJ C6
1965 F100 SW CVC 428CJ C6
1966 F100 LB RANGER 390 C6 sold finally
1965 F100 SW CVC 460PI C6
1965 F100 SW CVC 428CJ C6
1972 F100 RANGER XLT SW 428 C6 SOLD
1967 F100 SW CVC 521 C6
1967 F350 390 4 SPEED
1970 F350 428 4 SPEED
1974 F350 428 4 SPEED
1966 F100 523 STROKER C6 GEARVENDORS OVERDRIVE finished
RustNdust65
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Joined: March 3, 2016, 12:53 pm
Location: St. Louis, MO
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Re: Crown Vic ifs install question

Post by RustNdust65 »

I went ahead and welded it all up last night. I used 3/16" plate for the bracket base then 3/16 for the gussets also. Turned out really nice though very strong but I wouldn't be surprised if I had to go back like jim said. As far as measurements go I just let it sit naturally under the frame.

As far as cutting, spinning and welding the bushings I did that for the purpose of alignment issues and the actual design of the trailing arms themselves. I'm not saying that I did it right or wrong it's just how I did it because it made the most sense to me don't want to step on anyone's toes.
SLICKCOLLECTOR
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Joined: January 26, 2007, 8:04 pm
Location: eudora ks
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Re: Crown Vic ifs install question

Post by SLICKCOLLECTOR »

RustNdust65 wrote:I went ahead and welded it all up last night. I used 3/16" plate for the bracket base then 3/16 for the gussets also. Turned out really nice though very strong but I wouldn't be surprised if I had to go back like jim said. As far as measurements go I just let it sit naturally under the frame.

As far as cutting, spinning and welding the bushings I did that for the purpose of alignment issues and the actual design of the trailing arms themselves. I'm not saying that I did it right or wrong it's just how I did it because it made the most sense to me don't want to step on anyone's toes.
i don't understand cutting welding and spinning the bushings. by loosening the nut at the back of the trailing arm you can position the bushing parallel with the frame negating the need to cut and weld the bushing. i saw someone else do this and he didn;t know the nut allows the repositioning of the bushing different than the angle presented on the original crown vic frame installation.. but it is your truck. i look for ways to make it as easy as possible. ie. i used the existing holes in the frame for the alignment pins.

jim
1966 F100 SW 428CJ C6
1965 F100 SW 428 TL sold
1966 F100 SW CVC 428CJ C6
1965 F100 SW CVC 428CJ C6
1966 F100 LB RANGER 390 C6 sold finally
1965 F100 SW CVC 460PI C6
1965 F100 SW CVC 428CJ C6
1972 F100 RANGER XLT SW 428 C6 SOLD
1967 F100 SW CVC 521 C6
1967 F350 390 4 SPEED
1970 F350 428 4 SPEED
1974 F350 428 4 SPEED
1966 F100 523 STROKER C6 GEARVENDORS OVERDRIVE finished
RustNdust65
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Joined: March 3, 2016, 12:53 pm
Location: St. Louis, MO
United States of America

Re: Crown Vic ifs install question

Post by RustNdust65 »

I'll try to explain it has best as possible and again I want to reiterate I'm not saying I'm right or anyone else is wrong. I'm a firm believer in doing what works best for you. There's a thousand ways to skin a cat...I'm just stating what my opinion is and I could be wrong.

Ok so on an unmolested crown vic lower control arm (trailing arm) we are all aware they mount to the crown Vic's frame at an angle. All though the bracket is angled to the crown Vic frame the bushings is actually horizontal and parallel to the ground. Loosening the bracket and setting it flush to the f100 frame has now oriented the bushings to a diagonal angle. Knowing the function and purpose of the trailing arm is to absorb impact in transfer that energy inboard via bushings it makes a linear motion going perfectly lateral across the slot in the bushing instead of traveling diagonally almost violently possibly breaking welds or jerking the wheel from the drivers hands. Plus it really helps during the alignment process
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unibody madness
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Re: Crown Vic ifs install question

Post by unibody madness »

Matt I sent you a pm, and copied url to my son Matt. pictures would be great!
Turk build thread at:
viewtopic.php?f=32&t=18944

It does not matter what you think, it only matters what you do about it!
orangeRcode
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Location: Mustang, OK
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Re: Crown Vic ifs install question

Post by orangeRcode »

Following for future reference. :cheers:
RustNdust65
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Joined: March 3, 2016, 12:53 pm
Location: St. Louis, MO
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Re: Crown Vic ifs install question

Post by RustNdust65 »

Ok i have some pics to help explain what im trying to say

Image

Ok so this is the bracket and bushing straight off a CV held in the orientation it is mounted to the frame. Notice the slot in the bushing is horizontal.

If the nut holding this to the trailing arm was loosened and the bracket laid flat under the f100 frame that bushing slot would be diagonal in relation to the frame and bracket. The problem with that is like i said when something like a pot hole or rough roads or such are experienced the CV suspension will transfer that energy from the trailing arm pushing the end of the trailing arm straight in/horizontally inward up against the bushing.Now with it being diagonal that is a tremendous force pushing straight inboard and hitting a diagonal direction change going almost downward at this point. Could possibly break welds on brackets or cause premature ball joint wear.

Image

To fix this i simply cut the bushing barrel open spun the bushing horizontal then clamped and welded it close

Image

Very easy to do took maybe 15 mins to do both of them. Now you can see that slot of the bushing is now parallel to the ground and frame of the truck

Image

Again, there is a very good possibility that those that havent done this would even know the difference honestly but i didnt want to take a chance on something this important and easy.
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