Big Crown Vic swap question

Suspension, steering, brakes, wheels & tires

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cdc3jj
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Big Crown Vic swap question

Post by cdc3jj »

When I bought my truck (64 f100) it came with a nice set of 5x5.5 wheels that were a selling point. Currently the truck still has the straight axle up front, original drums all the way around and the original ford 9" rear. Several months back I bought a front disc brake conversion from speedway but have not installed it yet. I recently bought a crown Vic front suspension with intentions of making the swap to upgrade the steering and ride height. My issue is the lug spacing.

So... The million dollar question is... Is there a way to make the 5x4.5 crown Vic hub into 5x5.5? I've searched here, on the slick site and all over Google and everyone wants to talk about making the rear match the front. I want to make the crown Vic front match the back. Can it be done? Could I somehow use my disc brake kit (which is the original 5x5.5) to convert the CV over? Am I better off looking at different steering upgrade options and keeping the straight axle and installing my brake kit?

I have not unboxed the kit because... Well, life. Wife and I sold our house before we had somewhere to go, so no space to do much wrenching during the winter. But I digress... Thanks in advance for the advice.

Wheels are "Riddler" brand. I just like how they look.

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ultraranger
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Re: Big Crown Vic swap question

Post by ultraranger »

I have a 2003 civilian CV front suspension sitting in my shop. In looking at the front rotors, it looks light it MIGHT be possible to have them redrilled for a 5 x 5.5" lug pattern (??).

The problem will be with wheel clearance above the caliper, if you're trying to run a 15" wheel --since you mention the lug dimensions but didn't mention what the diameter is of the wheels you have.

Half of a 15" wheel diameter is 7.5". If I measure from the center of the CV rotor hub outward, the 7.5" mark puts me pretty much even with the highest point of the caliper. In other words, with a 15" wheel, there isn't sufficient room to clear the caliper.

If the disc brake kit is designed to put front discs on a straight axle F100, I highly doubt its configuration will come anywhere close for you to be able to adapt them to the much later model CV front suspension.

This is not a stead fast rule but, the general rule for wheel size is they should be 4" larger in diameter than the diameter of the largest rotor on the vehicle. A 2003-up CV rotor is 12" in diameter. This means the wheels should be at least 16" in diameter to have ample room for the inside of the wheel to clear the brake calipers.

The only upgrade to the Crown Vic front rotors/calipers I know of is to adapt '94-'04 SN95 Cobra Mustang 13" front rotors and their corresponding twin piston aluminum PBR front calipers. This will require at least a 17" diameter wheel but, these brakes take you right back to a 5 x 4.5" lug pattern.
Steve

1969 SWB F100 Ranger. 240-6, C-4, 9" N-case 31-spline Traction-Lok w/3.50 gears.

1968 Mustang. My high school car. Owned since 1982.

2003 Azure Blue Mustang Mach1.
cdc3jj
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Re: Big Crown Vic swap question

Post by cdc3jj »

The wheels currently on the truck are 18's.
ultraranger
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Re: Big Crown Vic swap question

Post by ultraranger »

cdc3jj wrote:The wheels currently on the truck are 18's.
In that case, it would go back to determining if the CV rotors can actually accommodate being redrilled for a larger lug spacing.
Steve

1969 SWB F100 Ranger. 240-6, C-4, 9" N-case 31-spline Traction-Lok w/3.50 gears.

1968 Mustang. My high school car. Owned since 1982.

2003 Azure Blue Mustang Mach1.
cdc3jj
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Re: Big Crown Vic swap question

Post by cdc3jj »

Ok. I'll do some investigation tomorrow and see if there's enough meat to drill it out.

Just out of curiosity... Would it be possible to remove the CV rack and pinion and mount it on the frame of the truck? I see unisteer and flaming river make cradles for mustangs and tri5's. Is the cradle used to get the rack closer to a straight line across the knuckles?

Is this even something worth investigating or would I be screwing up the steering geometry? I would love to end up with a manual rack as the little 223 (which I would like to keep) never had or wanted a power steering pump.
ultraranger
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Re: Big Crown Vic swap question

Post by ultraranger »

The CV front suspension is fairly wide. This means the R&P unit will also be wide --especially compared to a MII R&P. Don't know how adaptable the CV unit would be off the suspension assembly it was designed for.

It is certain, however, none of the CV R&P units were manual steering. They were all PS. A PS R&P unit with no hydraulic pressure applied to it will be sloppy.
Steve

1969 SWB F100 Ranger. 240-6, C-4, 9" N-case 31-spline Traction-Lok w/3.50 gears.

1968 Mustang. My high school car. Owned since 1982.

2003 Azure Blue Mustang Mach1.
cdc3jj
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Re: Big Crown Vic swap question

Post by cdc3jj »

I came to that same conclusion regarding the manual rack. If I try to graft a rack onto my current set up I think I would buy a mustang ii rack for better a fit. Hopefully I can pull a rotor and hub off the CV clip today and compare it to the wheel's lug spacing.
cdc3jj
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Re: Big Crown Vic swap question

Post by cdc3jj »

Pulled the rotor and hub assembly from the crown Vic and held it up to the 5x5.5 lugs on my truck... Ain't gonna happen. Not enough meat on the hub.

My drag link is 55 1/2" from the center of the bolts. So if I were to build a cradle attached to the frame, and mount a rack and pinion behind my straight axle (not on, but in line with attached to the frame) and the rack was in a straight line between the two knuckle mounts, would I be experiencing messed up geometry and unsafe bumpsteer?

This would probably be a good question for someone who has installed a rack on a 32 ford or something similar.
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