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DavidB
01-01-2005, 01:22 PM
I've been trying to read all the threads about replacements for our small rear rotors. I realize that wanting to upgrade them may be mostly a cosmetic concern, but what's wrong with cosmetics? :)

Anyway, the 2004+ armored Town Car comes with 13" nonvented rear rotors, which I was thinking should be a direct swap. I've also read elsewhere that these brakes came from the F150 Heritage?

http://www.lincoln.com/lifestyle/news.asp?item=15

The only stumbling blocks might be...does the armored Town Car have a different bolt pattern for the wheels? Maybe they're six-lug? And who knows if the price is reasonable, having to assemble a complete kit with Ford retail parts?

Any thoughts on this idea?

TTYL
David

cyclone03
01-01-2005, 04:05 PM
I don't know about the Town Car but the truck has a 5on5(or some metric type) bolt circle.The Marauder has the good ol 5 on 4.5".So that may trip you up a little.

Fourth Horseman
01-01-2005, 06:32 PM
I've been trying to read all the threads about replacements for our small rear rotors. I realize that wanting to upgrade them may be mostly a cosmetic concern, but what's wrong with cosmetics? :)


You and me, both. You'd think there'd be some easy bold-on replacement for the small rotors, but so far I haven't heard of anything.

BruteForce
01-01-2005, 07:06 PM
Even the Eradispeed BAER rotor replacements are the same size as OEM. I think its probably because the consensus would be that the major braking power needs to be up front. The rears just back them up.

Just as a side note. My BAER rears lock the rear so tight that I can't do a power brake burn-out without releasing the brake pedal about 35-40%. That's a pretty good grip I'd say.

fast Ed
01-01-2005, 07:52 PM
If that package is similar to the Limo package, the rear axle housing and axles will be different, with 31 splines and the "truck" size axle bearings, as opposed to the 28 spline in the regular Panther vehicles. The Limo package cars used to have drum brakes, that were based on the F-150 Heritage stuff. I'll take a look to see if I can find any listing for the rear brake parts on this Armoured package car when I'm back to work next week.

cheers,
Ed N.

DavidB
01-02-2005, 12:32 AM
If that package is similar to the Limo package, the rear axle housing and axles will be different, with 31 splines and the "truck" size axle bearings, as opposed to the 28 spline in the regular Panther vehicles. The Limo package cars used to have drum brakes, that were based on the F-150 Heritage stuff. I'll take a look to see if I can find any listing for the rear brake parts on this Armoured package car when I'm back to work next week.

cheers,
Ed N.


Thanks for the replies so far, guys.

Ed, if you access to the Ford parts listings, that'd be great!

I wasn't aware of different axle housings on the limo cars, I just assumed they used the same 8.8 axle assembly. Would that affect the external hardware I was thinking about retrofitting--backing plates/caliper mounts and calipers?

About the bolt pattern. If that's different, I assume the larger rotors can have the correct pattern redrilled? If it's a 5x5, there's room inside that to add our 5x4.5, but if it's a 6-lug, that could be a problem.

I think the most important piece would be the caliper mounts, to correctly place the caliper on a larger disc.

Would I get kicked out of the parts counter if I started asking this many questions in person?

Reading over this, I see I'm assuming a lot of things. That could be trouble!

TTYL
David

fast Ed
01-02-2005, 07:01 PM
I don't think Ford would have gone to 6-lug, because then they would have to change front hubs and rotors as well ... and from the specs shown, it would appear to have the standard 2003 - 2005 Panther brakes on the front.

The 31 spline axle shafts, with their appropriate larger bearings, generally are used in conjuction with a larger flange on the end of the axle housing, where the brake backing plate assy. bolts on ... this is the rectangular 4-hole flange on the very ends of the housing. If that's the case, then the Armoured vehicle brake assemblies would not bolt up to the flanges on your MM axle housings. As you probably know, the caliper mount is part of the backing plate.

In my parts dept., you may not get kicked out, but you might be asked to "leave it with us" if we were busy. ;)

cheers,
Ed N.

Todd TCE
01-03-2005, 06:37 AM
I'll toss out some info that might help. Or deflate your balloon.

Replacing the rotor is only half the problem. First thing you'd need is a rotor larger in dia, got that? Ok, now you'll need one that has the same bolt pattern. Check. Next you'll need one that fits the same parking brake shoes. Errr...? And of course it needs the same offset to do so.

Once you have all that covered you'll need to find a way to fit into the caliper bracket. Huh?

The caliper bracket anchors a fully floating caliper on the MM. This is not a bolt on caliper which removes the bracket with two bolts like the front. This means that your found rotor simply won't fit inside the torque arms of the cast iron plate. Not to mention that you'd never get the caliper back onto it....

Ok so what to do?? The only way you're going to achieve this is to find a complete rear brake package you can adapt to the axle housing. This is to include ALL the parts- caliper anchor bracket, parking brake parts, drum/disc and new caliper. Keep in mind that the bracket and shoe things go together and can't be mixed and matched very well. I'd start with an F150 to have a look see- it has a 13" x .500 solid package and is complete in this manner.

Or...you can weld completely new mounts onto the axle tube and bolt on some completely different package. One to include a caliper fixed parking brake perhaps.

Or...you can review my rear kit and see that I've been down this road already. To do the rear kit it took a bit of wild engineering on my part to pull it off. The final parts DO fit and DO the job well. But cost may be a bit more than you'd hoped. Actually the F150 idea won't be cheap either unless you do it the junk yard route.

This is not a sales pitch, in fact I'll be surprised if I sell many more rear kits at all given the cost, but it IS an alternative.

If you are going on a parts bin hunt I'd start with a caliper bracket that fits the axle flange. From there it needs the parking brake (maybe) and from there I'd worrry about the rotor and caliper.

No free lunch on this one.

SergntMac
01-03-2005, 06:48 AM
Thanks, Todd, I knew that if anyone could work it out, you would.

RoyLPita
01-03-2005, 07:05 AM
Aren't vented rear rotors more efficient? Race cars use them. MMs, CVs, & GMs use them. Vented rotors cool faster then nonvented.

Just my .02 and then some.

Todd TCE
01-03-2005, 07:08 AM
No arguement from me. I'm only tossing out ideas. And the F150 comes to mind. And it would probably be fine anyhow, but 'yes' to your question. On the other hand cold brakes don't work well either so it's a balance thing.

DavidB
01-03-2005, 08:07 AM
Todd, thanks for the reply. It has already occurred to me that if these Town Car parts work, I may have to use ALL of its associated parts, not just the rotors. The larger parts bin rotors are my goal, not the complete solution.

I haven't heard of anyone else considering this yet, this BPS Town Car is pretty new, announced only last April.

I haven't given up on this yet, I've just started. It's not like I'm trying to force completely dissimilar parts to work and fit, this is off a Town Car, a virtual mechnical twin to our cars.

[Edit: deleted this part which wasn't relevant to the discussion.]

About the non-vented rotors, that's what the MM has in the rear already. It's not uncommon for the rears to be solid.

About the cost, I don't know that either yet. It's possible this may end up costing as much as Todd's kit anyway, but I don't know that yet. If the parts require any more than minor machining to fit, then the project is out ot the scope of my skills.

It's entirely possible this won't work, but equally possible it will.

TTYL
David

Todd TCE
01-03-2005, 09:53 AM
David,

I hope you stumble upon something here. Who knows? More options are always welcome.

Brake tech 101-

One VERY important issue you have incorrect: pad swept area.

There are many kits (front and rear) that are not to you liking I suspect. When a caliper is moved outward on a rotor (or larger rotor fit) the caliper simply grabs a different part of the rotor. That's why you have 'unswept area' nearer the center or hat.

On the face of it this may seem a poor design. Not so. Pad size has little or no impact on braking. What? Yes, it's true. A small pad or a large pad with the same piston area has the same brake torque. It's piston area that clamps the rotor not pad area. So a pad that is 8Sq" for example exerts the same pressure if it is 4x2 or 2x4 when viewed.

But....a tall slendor pad is FAR more effective than one which is short and fat. This is called the "Effective Radius" of the pad. For most equations this is just the mean radius of the pad. (pad width/2- again actually called pad height but we don't look at it that way) This is where the brake torque is generated.

When you put the same pad on a larger rotor you increase its leverage thus reduce its dependancy on clamp force.

Now let's look at some examples. (simple ones please)

On a car with a 10 rotor and a pad that is 3.5" tall and 2.5" wide (backwards actually from how they are really measured but this is how you view it) the effective radius is 3.75" (10/2)-(2.5/2)

When you put on a 12" rotor with a pad such as those in a Wilwood caliper- 4.75 x 1.75 you lose .75" of your concern. But the effective raius is now 5.125" (12/2)-(1.75/2) This is a HUGE change in brake torque or performance.

Now lastly if we put the same Wilwood pad on the smaller rotor we get an ER of 4.125" vs 3.75 or an increase of .375". Not huge but there.

Keep in mind that pad area of both pads are nearly the same: 8.75 vs 8.81"
So, if the piston area pushing the pads is the same then the TOTAL rotor toque will be GREATER with the LONG SKINNY pad. Despite its not coming in on the nose of the caliper as far down the rotor surface.

Done.
If you'd like more specifics, just keep the tech q's coming...!
This is the kind of info you don't get on "point, click and order" sites.


**ADDED info: For those following and wondering where you go from here- One of the problems with some kits on the market today (in general) is that companies fit huge rotors and huge calipers to a car thus producing lots of clamp load at larger EFs. At first glance this seems a great idea. But in fact you tend to Over Bias the front of the car. To counter this a set up of this sort should have an equal upgrade to the rear, keeping bias in check. Remember, with the bigger rotor you need less piston. Not more.

TechHeavy
01-03-2005, 10:37 AM
This is not a sales pitch, in fact I'll be surprised if I sell many more rear kits at all given the cost, but it IS an alternative.
Todd, I hope you don't stop supplying before I get my kit from you this Spring, (I'm not quite sure how to interpret your above statement...). I'll be wanting the full 4-wheel set-up, and possibly SS lines as well, (not sure what performance benefit that has but I don't want to de-rail this thread... I'll ask later).
Will you still have the rear kits in the Spring?? :confused:

Todd TCE
01-03-2005, 11:09 AM
They aren't going anywhere really. So to speak.
I'm only suggesting it may not be the most cost effective choice so few are expected to sell.

I have two more sets of hats on the shelf for them and about 6 sets of brackets etc. etc. They use the same rotor and caliper as my Impala, CTS, Magum and others.

What I DON'T have a lot of are the cast iron plates on your car now. One set in fact from the last exchange. I doubt I'll buy more to pre build. Most likely is that you'll pay a healthy core charge on them and I'll wait for yours to come back. And they will be machined to order from here forward. Unless there's a big spike in requests that mandate I get a bunch from Ford.

And never worry; all my kits come with hoses.

TechHeavy
01-03-2005, 11:13 AM
They aren't going anywhere really. So to speak.
I'm only suggesting it may not be the most cost effective choice so few are expected to sell.

I have two more sets of hats on the shelf for them and about 6 sets of brackets etc. etc. They use the same rotor and caliper as my Impala, CTS, Magum and others.

What I DON'T have a lot of are the cast iron plates on your car now. One set in fact from the last exchange. I doubt I'll buy more to pre build. Most likely is that you'll pay a healthy core charge on them and I'll wait for yours to come back. And they will be machined to order from here forward. Unless there's a big spike in requests that mandate I get a bunch from Ford.

And never worry; all my kits come with hoses.
Ok, thanks Todd... I'll be in touch.

looking97233
01-03-2005, 11:56 AM
Humm, my thought is... If you are set on the armored limo brakes, by the time you figure in labor and machining to get the parts to fit our axle housiong... why not just get the whole axle assy. complete? Not only would you get the brakes, but the stronger 31 spline axles too. Any parts guys care to look up the price?

Todd TCE
01-03-2005, 01:21 PM
Never seen them.
But I'd not be surprised to find they are the F150 parts.
Ford can't have too many 13" solid rear disc/drum set ups.
Let's see....8.8 axle, 28 or later 31 spline....hmmm.

David Morton
01-03-2005, 11:40 PM
David, I got a good deal on the KVR 14" package through Dennis Reinhart and the rear rotors are stock sized. All 4 rotors are cross drilled and the cosmetic look is just fine. Plus the whole kit was a bolt-on, no modifications, and brother! I only thought I had good brakes before. The 14" fronts work so well I wouldn't dream of adding more power to the rears for fear of spinning the car around. This thing is gonna scrape the front bumper one day it dips so hard and the rear end rises up so much I worry the tires are gonna leave the road.

fast Ed
01-04-2005, 02:46 PM
Took a quick look today, I don't see anything listed specifically for an armoured vehicle. Regular limo package on 2003 - up Town Car does list different rear brake parts, I'm going to see if I can get some dimensions on them. Axle housing is a different part number between limo and basic TC. MM uses the same axle housing as the regular TC.

I'll post again if I can find some more info on this.


cheers,
Ed N.

DavidB
01-04-2005, 03:15 PM
Ed, thanks for looking up this information.

I'll admit that the chances I'm stumbled onto a bolt-on package are pretty low. I tend to think that if the Limo uses a different axle housing, the BPS car will too.

Like Todd said, they've probably just used an entire F150 housing, and its associated brake hardware.

No free lunch indeed! :)

TTYL
David

Krytin
01-04-2005, 04:03 PM
Just read an article in last Sunday's paper about The BPS. It tips the scales at a little over 6000lbs. and they left the stock drivetrain intact - 239 hp 4.6. The 0 - 60 times were pathetic. That thing better be missle proof - you might be able to outrun it on foot!

fast Ed
01-04-2005, 04:48 PM
Like Todd said, they've probably just used an entire F150 housing, and its associated brake hardware.

TTYL
David
I would doubt that it is an F-150 housing. The trucks are still using leaf springs, with no sort of axle locating device like the Watts linkage on the 98 - up Panther cars. One thing I did see in the listings was that there was NOT a different part number for the outer axle bearings ... meaning that they should be the same spline count. I forgot to try the axle shaft numbers themselves.

As I said, I'll try to get some dimensions on the Limo pkg. stuff. I did see different numbers for brake pads, rotors, calipers, and the backing plate assemblies. The Limo pkg. also had unique left and right backing plate assys., unlike the other Panther cars.

I'll report back when I have anything more. I'm a bit curious about this for my own use as well. I had plans to use the 96 - 02 style Panther rear brake assemblies on the 8" diff. in my old Cougar, they can be adapted on without too much fuss. But if I can put 13" brakes on the rear, to go with the monsters I have planned for the front, that would be even cooler. :D

cheers,
Ed N.

fast Ed
01-17-2005, 10:22 AM
Well, I ordered in a 2003 TC Limo pkg. rear rotor, since I couldn't find anything specific on the Armoured vehicle pkg. It is 13" diameter. It also has a HUGE hat area to cover the larger, F-150 sized parking brake shoes. I think that would spoil the look of it, the face of the hat would be visible about 1-1/2" all the way around behind the factory MM wheels. Taking a quick measurement, the hat area is just under 10" in diameter, approx. 3" larger than the factory MM rear rotor hat area. The actual surface for the pad area is no larger than the MM rotors. So the only benefit would be the increased clamping force from the leverage of having the pad area farther out from the centre. The brake pads have roughly the same surface area, I'm not sure about the caliper piston diameters, I don't have that info for comparison.

So considering that you would be into spending pretty big money for two rotors, two calipers, brake pads, the backing plate / caliper mounts and the associated hardware, and all of the parking brake shoes & mechanism, I don't think this would be a cost-effective way to do a rear brake upgrade, with questionable benefits. My guess is the only reason Ford put the larger rotors on the Limo pkg. cars, was to accommodate the bigger park brake shoes, for the extra vehicle weight.

cheers,
Ed N.

Todd TCE
01-17-2005, 07:17 PM
Ed,

Yup, we hit this one on the head. That's the F150 rear brake package. BIG problem with it for the aftermarket is the rotor surface width. That hat of about 10" leaves only about 1.5" of swept area to work with. Bad news is that every caliper I can work with reguires about 1.75" or a tad more to accomodate the pads AND the body of the caliper. The 'nose' of the caliper bumps the hat well before the pad is sitting at the proper radius, thus leaving about 1/8-1/4" of pad overhang. Not the end of the world but not right either....

What WOULD be a decent compromise is this package on the rear and my kit up front. The bias might be in pretty good check. Cost wise however if these parts run the normal guy $1000 total to do; rotors, calipers, brackets, cables, pads, hardware, parking brake parts, yada, yada, yada....You'd still be dollars way ahead with my rear kit even at $1500.

Warpath
01-17-2005, 07:21 PM
Sorry if I repeat anything. Thread is too long for me to read at the moment.

BPS should have the same bolt pattern. As far as I understand, its a limo with armour. Limos get a unique rear end. I don't know what's in it though. No drum brakes anymore.

DavidB
01-19-2005, 12:22 PM
Ed, thanks for all your research on my question--I think you provided more information than I ever expected from the board, and I appreciate it much.

Sorry my idea didn't pan out. :)

TTYL
David

fast Ed
01-19-2005, 01:12 PM
No problem David. I enjoy researching the potential mixing & matching of OE Ford parts on to other applications. You would be amazed at the amount of non-stock stuff on my 68 Cougar that does have some sort of Ford number on it. :P

I was hoping for a fairly easy 13" rear brake combo myself, to go with the 14" that will likely be going on the front.

cheers,
Ed N.