Crown Vic crossmember install/Rear Truck arm install

Ford IRS ???
Marcus...

 

Thanks, so far so good. First time for me.

 

It is, the crossmember is from a 04 Town Car. I put all new components on it and used a reman. rack for a 08 which has no electronics on it. I used Cop car struts which have a heavier spring ( or so they say ).

 

I have the info recorded in a file but the cop car springs have several hundred pounds more pressure per side. The wire is larger diameter making it easy to tell which is what.

 

TA, Thanks for the info, I like it's bolt-able vs welded, I see some of the ifs is aluminum, gotta look closer I guess. Crossmember & lower a-arm AL? Upper a-arms & spindle-carrier = ??? But I was asking if the rearend will be from some ford irs. I saw a comment about truck arms, but ???
TIA.
Marcus...

 

The Crossmember, steering knuckles, rack and LCA's are aluminum. The UCA's are steel. The trailing arm brackets that locate the rear of the LCA are aluminum. Those came from a company called Range products.
Right now I will probably use a 9in. I have given some thought to a IRS but have not looked at it very hard. Something from a Ford may work or a unit from a Hellcat. I don't know about Fords but the Chrysler stuff has a 7.5 in. ring gear and that is pretty unimpressive to me. In the beginning I thought about truck arms and that could still happen. I have access to those in that I can go pick a pair up from friends shops on a loaner basis lol. But a parallel 4 link with coil overs is more than likely what will end up under the rear. The 4 link would be the easiest to tune. I have always used Dana's and leaf springs so this is all new ground for me. But I have friends to set me up with what I need how ever I go.

 

Thanks for the reply. Are there any Ford bolt-in/up A-arms in Alum? May as well... .
Fords' IRS does seem interesting, if not ugly as sin.
Ain't no Jag, much less a T/A from some corvette, but those aren't cheap either(when finished). & since most boneyards don't have the stuff I'd prefer, I've been contemplating the stuff that's available. Maybe(???) it could be made to look right? After all, even the Jag gets uncaged 1st...
Just was thinking since you're using the front IRS from a Crown Vic, maybe the rear IRS from a similar model??? .
Marcus...

 

The Ford IRS use an 8.8 center section, so they can handle reasonable power. Plus the bolt pattern will match the front. But can't go wrong with a solid 9-inch.

FWIW, I have Jag IRS and IFS in my avatar 52 GMC. The Jag is basically a Dana 44 center section. But bolt pattern is 5x4.75. A real easy swap though in my truck.

 

I have not seen any aluminum uppers, a person could always polish the lowers and the crossmember or just paint it all chassis black.

 

The cop car front spring is rated at 1940lbs. The standard is 1650lbs. There are both steel and alum lowers. In case anybody is curious, the 2015 and newer mustang's irs is a super 8.8. It is way different from the earlier irs's. It has 34 spline axles a different clutch pack. All are posi trac no matter what ratio. You can't install a 3.55 and lower gear in a 3.15 carrier.

 

Thanks wfo,
That is good info to know, especially on the carrier.

 

wfo , What rearend did you put under your truck ? I wonder if the pinion is centered in the super 8.8 ? A quick search shows you can find them for around a grand. This sounds much more inviting to me than having to build a complete axle or spending my friends 2-3 k. for a finished 9in. Plus the rear brakes would be finished with some nice big disc's.

 

The pinion is offset to the right side as I recall. I have 1.25" stuck in my mind but that could be wrong. The rear brakes are large enough that the correct 17" wheel will be required to clear. I had to grind on the caliper ribs to use the Mustang Bullitt wheels. The earlier mustang 17" wheels cleared easily. That rear has 12mm studs, also. I drilled the corvette front to the 4.5" bolt pattern and 12mm studs so I could use one lugnut. That rear is the same width as the wide crown vic rear. That could be a reason to use the earlier 90's cougar and tbird 8.8 assembly. I have used both on trucks so if you look at my youtube channel you will find some video of what it looked like installed.

 

More info on the 2015 Mustang rear. I went out and did some measuring on the rear of my truck. I laid 2x4"s flat on the ground and measured inside to inside to see what the outside to outside on the tires was. 75". That's with the 2x4's laying down so the fattest part of the tire still protruded lightly. The wheels have an everyday tire on them, nothing with a wide bulging sidewall.

 

wfo guy, thanks for all the info. I will have to put my hands on one and go from there.

 

I went buy a friends yard and they had a 2017 assembly in the core pile so I got to take a up close look and a few measurements. Probably not what I am looking for for this truck. I went by another friends shop and barrowed a pair of Cup Car truck arms. I have the drivers side setting in place and this looks promising. So shit we'll be riding next week ! It is sitting at ride height in the photo. And I have the 9in. on hand so we will see where this leads.

 

If you go with leaf springs, life is simple. If you go with a normal (?) 4 link with panhard and coil overs, that is a good choice but not cheap. If you use the triangulated 4 bar, some say it isn't as flexible as the straight 4 link. Getting the correct ride height before deciding might be something to think about. There's plenty of choices. Something I don't do well anymore. LOL.

 

Nothing wrong w/the 2-link truck-arms.
Marcus...

 

I got the arms , now I have to visit another shop for brackets and a look at how the crossmember is done. " I get by with a little help from my friends "

 

Are those 2 left-side arms? Or do my eyes deceive me?
My pair of oem arms are mirror-images of each other.
Marcus...

 

They are left and right , the one with the tall bracket is for the drivers side and the bracket is for the track bar. Good eye though they do look the same in the photo !

 

Old eyes suck... They appear to have the same directional bend, instead of mirror-image, to properly form an "A" w/the axle-mount perpendicular to the axle-tube. Glad they're correct.
Marcus...

 

We will be ridin next week ! well maybe not. I have got things laid out to see what has to happen next ? The 9in may work offset wise ? I just haven't gotten there yet. I think I want a piece of 2 x 4 for the frame rail instead of the 2 x 6 , time will tell.

 

So I have the axle housing centered in the frame and a too short driveshaft slid in the trans and eyeballing it it looks to be about a inch and a half to far to the right ? not a Ford guy so I have some looking to do and see how they offset some other housings.

 

Axle offset is real common. As far as I know, that was done for steering apparatus clearance. It's common to shorten the housing and use a different axle on the modified side.

 

I have access to more housings both Cup Car full floaters and stockers. The budget plan is to find one to fit as is. Time will tell what I find. The hard part is getting the stuff where you can get to it to get good measurements as I sure can't pick them up any more. Fat man fabricators had a huge pile of them in his auction a couple weeks back. They probably all went to the crusher.

 

Just in case you didn't see, the risers on a crown vic crossmember are for an offset engine mount.

 

Pinion does not need to be centered.

 

That would be correct, but it needs to be centered to the output shaft of the trans. That is what we are after here. On the cheap, without cutting or buying a new housing , but there may not be a stock 9 inch with the right configuration .
The floaters which are Cup Car pieces are pinion centered .

 

It does not have to be centered to the transmission.There are many Ford and probably others that came from the factory like that.