TCCoA Forums banner

1 - 20 of 21 Posts

·
Registered
Joined
·
278 Posts
Discussion Starter #1
I bought a trac loc (Not the whole pumpkin, just the trac-loc carrier) from a 97 Mustang. Can I use this in my T-Bird or would I have to get one that came out of a Bird or Mark VIII?

- Mark
 

·
Registered
Joined
·
1,131 Posts
From what I gather as long as the pumpkin size is the same(i.e 8.8 or 7.5 or 9) then it will work. It gets a little tricky with the IRS though but I've heard from people here that it will work if you use a solid axle unit in an IRS pumpkin. Do a search and you'll find some informative threads.

Adam
 

·
Registered
Joined
·
7,758 Posts
I'll jump into this... :D

Yes and No. :leftright

Here's the general take from multiple sites:

"Officially" there is a difference in the side gears between an IRS and a non-IRS (Mustang) 8.8 differential. The IRS side gears have a groove machined in them to hold the spring clip that is on the half-shafts, whereas the non-IRS differential does not.

With that said, some people have used the Mustang 8.8 in an IRS vehicle and report no problems.

My personal recommendation is to get one from a Cobra (pre-supercharged, but with the IRS – supercharged Cobra’s have 31 spline half-shafts), a Mark VIII w/traction lock, or a T’Bird/Cougar w/traction lock.

Again, just my opinion. :thumbsup:
 

·
Registered
Joined
·
1,131 Posts
Yeah the clips are the only difference I belive from the IRS to non-IRS. The clips are supposed to hold the halfshafts in but they will be held in by the knuckles at the other end.

Adam
 

·
Registered
Joined
·
7,758 Posts
I don’t want to start an argument or anything and I’d like to get a little clarification if possible since I’m not 100% sure on this.

But I think the clips do more than hold the shaft in, I think they also allow the inner CV joint to operate as designed. (Obviously the big honking nut on the end of the shaft is the main load bearing device for keeping it installed. :) )

Don't quote me on this because I'm not sure of my information, but the outer CV joint is just a standard "U" joint type of assembly whereas the inner CV joint is a dual function "U" joint and also a lateral movement joint. (Or vise-versa, I may be revered and/or completely wrong! :D )

But the slight lateral motion of the half-shaft as it moves in its arc is supposed to be handled by one of the CV joints. Without the clip, the half-shaft can slide in and out of the pumpkin. It’s a very slight movement and won’t hurt anything and the shaft surely isn’t going to fall out or anything, but will it create more wear on the seals.

Again, I’m just trying to get some clarification and I’m not saying the Mustang won’t work. I figured this post was as good as any other to analyze how the rear IRS actually works. :thumbsup:
 

·
Registered
Joined
·
1,131 Posts
I hear ya. I'm by no way an expert in the rear diff. I'm just regurgitating info that I've recieved from people here and other places. Any info is great as it contributes to everyone reading.

Adam
 

·
Boom.
Joined
·
5,238 Posts
94 Daily Driven 4.6L said:


My personal recommendation is to get one from...a Mark VIII w/traction lock
Good luck finding that ;) j/k Marks only came with traction control, which means no TL.
 

·
Registered
Joined
·
7,758 Posts
Um, my 97 LSC has TL and TC. :D

I think the Gen I's only didn't have both, but not 100% sure. :thumbsup:
 

·
Registered
Joined
·
1,544 Posts
The sticker on the door jamb should indicate that a 97 LSC came with a 3.27 open (AX code = 5) . I haven't seen them all but afaik all Marks came with TC and no TL. If one has TL it was added by the owner. I'm pretty sure any Mark owner that's at all worried about performance wants a FRPP pumpkin w/ 3.73 or 4.10 TL for Christmas...
 

·
Registered
Joined
·
7,758 Posts
The factory tag on my differential (aluminum) says 3L27 (One of the first things I checked)

If I disable traction control I leave two black marks when flooring it from a dead stop

If I turn on traction control, the car barks one tire and then falls flat on it's face as it pulls timing and won't get out of it's own way (and it illuminates the "spinning tire" emblem on the dash :D )

I really don't think this car has been modified at all based on the condition. I have found nothing that isn't OEM.

I'll have to check the door this evening since I'm in the T'Bird today. :thumbsup:
 

·
Registered
Joined
·
1,544 Posts
94 Daily Driven 4.6L said:
....If I turn on traction control, the car barks one tire and then falls flat on it's face as it pulls timing and won't get out of it's own way (and it illuminates the "spinning tire" emblem on the dash :D )
......


Yup, there's a locker in there.... the fact it's aluminum would seem to eliminate the obvious that it was swapped from an SC, they were all iron. I know the LSC is supposed to be a "performance enhanced" model but it seems curious that it would come from the factory with both considering it acts as it does w/ TC on, and if I understand the traction control correctly that's what it should do with a locker. Original owner probably ordered it that way? So much for grandpa being the only Mark VIII customer when they were new. :)
 

·
Registered
Joined
·
2,936 Posts
94 Daily Driven 4.6L said:
My personal recommendation is to get one from a Cobra (pre-supercharged, but with the IRS – supercharged Cobra’s have 31 spline half-shafts), a Mark VIII w/traction lock, or a T’Bird/Cougar w/traction lock.
Just to add a little more. The '01 cobra had 31 spline inboard shafts also. :D The '99 is the only one that didn't.


Russell
 

·
Registered
Joined
·
7,758 Posts
Yep, I stand corrected!! I thought they went with the 31 when they went with the supercharger. :eek:

Sorry for the misinformation. :leftright

Oh well, live and learn huh! :thumbsup:
 

·
Registered
Joined
·
2,129 Posts
94 Daily Driven 4.6L said:

If I disable traction control I leave two black marks when flooring it from a dead stop

If I turn on traction control, the car barks one tire and then falls flat on it's face as it pulls timing and won't get out of it's own way (and it illuminates the "spinning tire" emblem on the dash :D )

I have T/A and the FRPP unit. With T/A on, I floor it, the car launches like a mofo. With T/A off, car launches like a mofo. I can't really tell a difference with it on or off. When I had the open rear-end the difference was huge.
 

·
Registered
Joined
·
7,758 Posts
So you're saying that you can't spin a wheel with it either on or off?!? (Sounds like you're lacking in power..... j/k... :rofl: )

Just kidding. :thumbsup:

I really think the traction assist on the Gen II's are a lot different than on the Gen I and/or the MN-12. I'm going to research all three (94 MN-12, 96 Mark VIII, and 97 Mark VIII) tonight to see exactly what the differences are (if any). :D

I'll post my findings tomorrow and hopefully put this to rest. (Mainly because I've been wondering this myself for a while now) :thumbsup:
 

·
Registered
Joined
·
4,205 Posts
Man, I've posted this quite a few times, I have done the swap, and here is the EXACT differences.

The IRS Trac-Lock has a BEVEL in the gear, not a slot. It is there to make it so that you can take the halfshafts out of the car without dissassembling the entire rear. You can put the solid axle Trac-Lock in the IRS with NO RETENTION PROBLEMS, because the circlip will slide all the way past the gears, and expand. Where you run into a problem is when you have to take a halfshaft out for some reason. Without the bevel, the circlip will not compress itself and slide out, which leaves you 2 options, pry hard enough to break the circlip (not really an option for me!) or take the cover off the rear, and pop the circlip off with a pick, and then pull the halfshaft out. There are NO safety issues with running a solid axle trac-lock in a IRS rear, and it will not allow the halfshafts to slide around.

Another option is to order the side gears from Dan Newman, he found the part numbers for Ozzman, and swap them out, no big deal, and I believe they cost $70.
 

·
Registered
Joined
·
2,129 Posts
94 Daily Driven 4.6L said:
So you're saying that you can't spin a wheel with it either on or off?!? (Sounds like you're lacking in power..... j/k... :rofl: )
Expensive tires help alot. As long as it's above 45 out, they hook up very well. I run SUMMER tires in the summer and snows in the winter. BIG BIG difference in the performance of a summer tire vs a all-season.

I was quite surprised with the trak-lok unit that i could hook up as well as I can, thought I would have needed alot wider tire to hook up as well as i do. Haven't been to track (autocross) yet to see how well I can hook up there. But no problems giving her hell from a stoplight thus far.
 

·
Registered
Joined
·
1,131 Posts
Thanks for the clarity Rich. Somehow I've missed/missunderstood that from my previous searches. Makes a lot more sense now.
 

·
Registered
Joined
·
129 Posts
Rich95XR7 said:
Man, I've posted this quite a few times, I have done the swap, and here is the EXACT differences.

The IRS Trac-Lock has a BEVEL in the gear, not a slot. It is there to make it so that you can take the halfshafts out of the car without dissassembling the entire rear. You can put the solid axle Trac-Lock in the IRS with NO RETENTION PROBLEMS, because the circlip will slide all the way past the gears, and expand. Where you run into a problem is when you have to take a halfshaft out for some reason. Without the bevel, the circlip will not compress itself and slide out, which leaves you 2 options, pry hard enough to break the circlip (not really an option for me!) or take the cover off the rear, and pop the circlip off with a pick, and then pull the halfshaft out. There are NO safety issues with running a solid axle trac-lock in a IRS rear, and it will not allow the halfshafts to slide around.

I am not trying to cause problems, but I pulled my axles out with no problem. I changed nothing. They "popped" in and out just like my factory on did. Maybe I am just lucky, maybe. I just know I have a 97 stang trac loc with a load spring out of a 4x4 truck.
 
1 - 20 of 21 Posts
Top