What years do I look at? And does it have the same lug pattern as the CV IFS.

 

89-97.. here are some threads and sites for your perusal:

Team 321 Cougar/T-bird MN-12 Independent Rear Suspension Kit
Classic Trucks: MN-12 IRS Retrofit Thread
FTE Thread: elgemcdlf's '70 F100 CV IFS & MN-12 IRS

 

'89-'97. It does not have the same pattern. You have a few options available though. The pattern of the CV is 5x4.5 & the MN12 is 5x4.25. You can use spacer/adapters to get the correct pattern, wheels that are drilled for both patterns (this is what is currently on my truck), you can have the hubs & rotors redrilled for the larger pattern or you can swap out the hubs for hubs that fit the Cobra IRS. They have the same pattern. You then either have your rotors drilled or use rotors from a Cobra. They are larger so with that option you will need adapters that move the caliper outward from the axle. I have information on a pair of those adapters. I also posted a list somewhere & may still have it around of potential rotors that will go right on the Cobra hubs & should work with the stock caliper location.

 

Thanks elgemcdlf I like what you did on yours for a rear end nicer then channeling the frame but didnt see the years for the IRS so now I know what to go find, Right now I'm in the preplanning stage so it will be quite a while before anything gets going but I can gather the parts.

 

You're welcome. The 2nd link HIO Silver posted is an article I did on just the rear swap. I think there may be more detailed info in it than my build thread here. Been a bit since I wrote it so I am not positive.

 

The Mark 8's last year was '98. Why isn't that year included? Something different about it?

Jim

 

The Lincoln unit is actually '93-'98. It is know as a FN10 not the MN12. The difference being MN stands for Mid-Size North American & the FN stands for Full-Size North American. Other than the center sections being different (case is all aluminum) I know of no other difference between the MN12 & the FN10. To the best of my knowledge the FN10 came with 3.08 gears. The MN12 came with a variety of different ratios even including a Limited Slip (very difficult to find). The FN version was an 8.8 center section. The MN could have came with either a 7.5 or an 8.8. The version I recommend is the 8.8.

Both rears are 28 spline axles/inner CV joints. As I understand it all car 8.8 units are 28 spline along with almost all Rangers. Truck 8.8 units are 31 spline. 31 spline inner CV joints can be bought but they are not cheap & really would do a person no good as the outers are still 28 spline. If you are swapping in a Limited Slip to the MN or FN center section be aware the spyder gears are different for the IRS. They have a groove machined in them for the circlip on the end of the CV joint.

Some have run without machining this groove into the gears with no circlip & report no problems. Others have retained the circlip & say when it comes time to remove the axle shaft it is basically frozen in place. I am currently attempting to buy a set of spyder gears for the IRS & Limited Slip but have not been able to locate a set. I most likely will look for a set out of a car & have the groove machined in them using the open gears as the pattern. My Limited Slip unit came out of an Explorer so it is set up for 31 spline axles.

 

A list I just found....Not sure if its all right or if they'll work

INDEPENDENT SUSPENSION

93-98 Lincoln Continental Mark VIII

99-04 Mustang SVT V8 (31 spline from 03)

89-97 Thunderbird

00-up Lincoln LS (V8)

98-up Explorer/Mountaineer

97-up F150

98-up Expendition/Navigator

02-up Explorer/Mountaineer

03-up Expedition/Navigator (4.6L V8)

Cover Bolts: 10

Ring gear diameter: 8.8”

Pinion shaft diameter/splines: 1.625/28

Axle shaft diameter/splines: 1.29/28 or 1.32/31

Available ratios: 2.26, 2.47, 2.73, 3.08, 3.27, 3.45, 3.55, 3.73, 3.90, 4.10, 4.30, 4.56, 4.88, 5.13, 5.71, 6.14

 

These are easy swap into our trucks.

This rear was designed by Jaguar. It has an 8" carrier & there is practically no support for this rear. You can not get a Limited Slip diff for this rear.

 

IIRC the limited slip diffs for the Mark 8's were only in LSC models.

Jim

 

I believe you may be thinking about the traction control on Lincolns. It is not Limited Slip. When it "sees" a spinning tire it intentionally bogs the engine down to reduce torque.

I have not read anything about Lincolns having Limited Slip. The Mustangs & Super Coupes did.

 

No, actually I am talking about limited slip differentials on Lincolns. I am a member of a Mark 8 forum, and they mention on their site that LSC's came with limited slip differentials, and a lower (3.24:1) ratio compared to the standard Mark 8 which came with 3.08:1. They also came with true dual exhaust.

Jim

 

Well that's good to know. Makes shopping for pieces parts easier. Thanks for the info.

 

TL unit

Traction-Lok Assembly for 8.8" Rear End - 28 Spline - IRS Specific!, Driveline & Transmission | Super Coupe Performance Parts

Traction-Lok Assembly for 8.8" Rear End - 28 Spline - IRS Specific!
Complete new Traction-Lok (TL) assembly from Ford! This TL unit is designed to specifically fit the Independent Rear Suspension (IRS) cars such as the '89-97 Tbirds/Cougars, the '93-98 Mark VIIIs, and the 28-spline IRS Cobras. The TL units from a solid axle car are NOT compatible with the IRS applications.

This unit is for 28 spline half shafts and is perfect for replacing your existing worn out TL or great as an addition to a car that came from the factory with an open differential.

The following cars came from the factory with an open differential and can be retrofitted with this new TL unit:
All '93-98 Mark VIIIs
All '94/95 Tbird SCs with automatic transmissions
Many V8 Tbirds/Cougars from '91-97...check your axle code on the door and use a Ford shop manual to decode if you have a TL installed or not.

These units are rebuildable with an inexpensive new friction/steel kit.

Price: $319.99

 

No Mark VIII came with a track loc rear, but the LSC had 3.27 and the regular had 3.07. 89-93 MN12's with ABS came with rear disk and a track loc rear. Auto trans got 3.27 and manual got 2.73 ratio.

there was one weird ratio that was 3.26 and I think it was in 94-95 SC with traction control, but I don't remember.

Also note the Mark VIII control arms don't have the provisions to hold coil springs because they have air ride. I've done a few conversions and made perches for the mark VIII and its not to complicated.