Question about Rear-Ends

[Silver03MM]

Okay, this is an area on cars that I am some what confused about. This is now in regards to the Marauder but to my 1967 Mustang. The bottom line is I want a Posi-rear in it. Right now it has the stock rear-end, where only one tire burns out. The question is how do I make them both spin? Do i just need to buy new gears or do I have to buy a whole new rear-end? What exactly am I looking for?

[Rider90]

You're looking for Posi-Traction...or I think ford calls it Trac-Loc...basically a limited slip rear differential available through most suppliers such as jegs or summit :burnout:

[Silver03MM]

So i just need a new differential that will fit in the stock rearend housing?

[fastblackmerc]

So i just need a new differential that will fit in the stock rearend housing?

Might also need new axles.

[Silver03MM]

Does this cost a lot of money? Cause I figure if I get a new differential, I should also get better gears (2.75) or something that i currently have, and now new axles? Why would the axle have to be changed? To work with the differential? I'm sorry I'm not good with the make up of the rears on cars. All I know is my Marauder has an Independant rear and my mustang is a solid rear.

[Rider90]

2.75? Unless you're pushing a lot of power I don't think you need a limited slip :P Sounds like a great highway cruiser...

[RF Overlord]

All I know is my Marauder has an Independant rear and my mustang is a solid rear.

Silver, the MM does not have an independent rear suspension...it's a conventional solid or "live" axle.

What you need for your 'stang is a Trak-Lok centre "carrier". You can re-use your existing ring and pinion gears, or get new ones of a different ratio if you desire. I've never bought just the carrier, so I have no idea what it would cost.

Unless you have experience replacing rear gears, it's not a DIY project, as special tools are needed. You may be better off searching the boneyards for a complete rear axle w/Trak-Lok and replacing the whole thing...that is a relatively easy job.

[CRUZTAKER]

Don't quote me, but I believe I paid less than $300 for a high performance Auburn LSD for my MM. I burned out the OEM LSD at the track.

Eaton also makes a great LSD. You likely need only call Summit to find your application size and price. The LSD should pop right in to your existing housing with no other changes. Perhaps while it's open you may consider gears as well.;)

[BillyGman]

I believe that the Eaton posi units are about $400 through www.summitracing.com (http://www.summitracing.com/) ...and while you're in there, I'd change the gars if i were you, IF better acceleration is what you're after. However, another option that you have is to purchase a Powertrax "No-Slip" unit made by Richmond gear through Summit Racing. The Powertrax sytem is available in models specifically for rear ends that are NOT posi, and installing one of them in such a rear end like your car has will change it into posi with out even having to change nor even remove the ring & pinion gears during the installation. I can't say that I've ever used one of the Powertrax rears, but the advantage to them is that they're a Locker type rear which doesn't have any clutches to wear out. And Richmond's claim is that these "No-Slip" Powertrax Lockers do NOT make noise around turns like their original Locker rear and other brands of Lockers always do. But you might want to call them to talk to a tech guy concerning that. I've seen them in Summit Racing for $400-$450. Below is a link to the Richmond gear webpage that has the Powertrax "No-Slip" rear. And you'll also see a couple pics of this product too. I've often thought about the possibility to use one of these in my Marauder should I ever destroy the posi ("Trac-Lok") unit because of the amount of torque I'm putting through it. I've viewed the installation instructions via PDF file, and I've learned that you don't even need to remove the differential (aka "carrier") from the rear end to install this unit. You simply remove the cross shaft pin, and the spider gears and clutch paks, and replace them w/the Powertrax system. So there's no messing with the ring & pinion gears nor w/having to shim anything. So it looks like mopst do-it-yourselfers can accomplish this.



http://www.powertrax.com/noslip.html

[merc406]

If your running a big block this is a great site for you, also here's more on rears, just don't do what this guy was thinkin about for street use. http://www.network54.com/Forum/message?forumid=74182&messageid=1103032597

[BillyGman]

That looks like a good site that Merc406 has supplied you with. Just keep in mind that there are two different "Powertrax" rears. Both are locker rears however, the "Lock-right" one is their original Locker, and is noisy arond turns. But Richmond Gear's claim is that their newer Powertrax "No-Slip" Locker is quiet around truns and is perfectly suitable for street cars. From what I've heard, guys with 4x4 trucks that often go off-roading use the original "Lock-right" model. But since that one is noisy, then you wouldn't want that for a street driven car. BTW, these aren't to be confused with spools nor with "mini-spools" that cannot be used for the street. But again, if you do consider one of these, I suggest that you make some phone calls to Richmond gear. Don't take my input here as being the final word, because as I've previously mentioned, I cannot claim to have ever used one of these Lockers before. it just looks like something that I would consider. I hope this helps you.

[Silver03MM]

Well the Mustang I have is a basic 289 with 225 horse, I just want better traction with both tires spinning. So i'm talking around $400 plus installation charge?

[BillyGman]

Well the Mustang I have is a basic 289 with 225 horse, I just want better traction with both tires spinning. So i'm talking around $400 plus installation charge?
I'd say that's about right, unless you opt for a gear change, which would be an addition $250 for the new Ring & Pinion gears along with related parts.

[JACook]

Okay, this is an area on cars that I am some what confused about. This is now in regards to the Marauder but to my 1967 Mustang. The bottom line is I want a Posi-rear in it. Right now it has the stock rear-end, where only one tire burns out. The question is how do I make them both spin? Do i just need to buy new gears or do I have to buy a whole new rear-end? What exactly am I looking for?OK first, you have to know what kind of rear is under your 'Stang. Ford used three different styles of
rearend in '67, depending on what engine was used.

An "A" or "C" code '67 will have come with an 8" rear. The 8" doesn't enjoy nearly as much aftermarket
support, as the 9" or 8.8". That's going to limit which of the options given so far that will be available,
to you, unless you change your entire rear to a 9" out of a HiPo or big block Mustang. (Or a Lincoln
Versailles disk brake rear, but that's probably more modification than you're looking to do right now.)

The 8" rear is perfectly capable up to around the 300HP level, and is considerably lighter than the 9",
unless you pop for the aluminum carrier.

The factory 8" Traction-Loks are kinda rare, but they can be found. Expect to pay ~$300-$400 for a
used center section at the swap meet. Then you'll need to have it refreshed, and it'll probably still have
the 2.79 gears in it. If you're going junkyarding, look for an intermediate-size car, then look at the axle
code on the door data plate. Cars with TractionLok will have a letter here instead of a number.
The ratio tag on the rear will also have a letter "L" inserted into the ratio. i.e., 3.25 becomes 3L25.

Or better yet, Check with Currie Enterprises (http://www.currieenterprises.com/).
Currie is regarded as one of the best one-stop-shops for 8" and 9" rears. They're located out here in The O.C.

Currie makes a 4-pinion replacement LSD for the 8" that's stronger than the factory piece. They also offer an
aluminum 8" carrier for those looking to further minimize the weight and add strength. (But at a price...)
You can find all their 8" stuff at: http://www.currieenterprises.com/html/custom/8inch/rearend8ford.htm

[Silver03MM]

Thank You much JACook, that alum. 8" sounds good but I would have to build it with a differential and my gears but looks really good.

[JACook]

Thank You much JACook, that alum. 8" sounds good but I would have to build it with a differential and my gears but looks really good.
No problem, I'm sure Currie will be happy to sell you those parts as well... :)

[jaywish]

Hi Silver,

Where are you located?

Did you determine what size rear you have? 8. pr 8.8 or 9?

Ford Raceing has new locking 8.8 diffs for about $180 + shipping.

If you want a used 8.8 diff let me know I'll put you in touch with someone.

I just had a 8.8 posi installed in my wagon.

Jay

[Silver03MM]

I'm in Northern Jersey

[ModMech]

OK first, you have to know what kind of rear is under your 'Stang. Ford used three different styles of
rearend in '67, depending on what engine was used.

An "A" or "C" code '67 will have come with an 8" rear. The 8" doesn't enjoy nearly as much aftermarket
support, as the 9" or 8.8". That's going to limit which of the options given so far that will be available,
to you, unless you change your entire rear to a 9" out of a HiPo or big block Mustang. (Or a Lincoln
Versailles disk brake rear, but that's probably more modification than you're looking to do right now.)

The 8" rear is perfectly capable up to around the 300HP level, and is considerably lighter than the 9",
unless you pop for the aluminum carrier.

The factory 8" Traction-Loks are kinda rare, but they can be found. Expect to pay ~$300-$400 for a
used center section at the swap meet. Then you'll need to have it refreshed, and it'll probably still have
the 2.79 gears in it. If you're going junkyarding, look for an intermediate-size car, then look at the axle
code on the door data plate. Cars with TractionLok will have a letter here instead of a number.
The ratio tag on the rear will also have a letter "L" inserted into the ratio. i.e., 3.25 becomes 3L25.

Or better yet, Check with Currie Enterprises (http://www.currieenterprises.com/).
Currie is regarded as one of the best one-stop-shops for 8" and 9" rears. They're located out here in The O.C.

Currie makes a 4-pinion replacement LSD for the 8" that's stronger than the factory piece. They also offer an
aluminum 8" carrier for those looking to further minimize the weight and add strength. (But at a price...)
You can find all their 8" stuff at: http://www.currieenterprises.com/html/custom/8inch/rearend8ford.htm

Your '67 almost certainly has the 8", most cars did, even the v-8s thru '69 as I understand it. They are easy to set up, but not as easy to install a LSD in as the 8.8 because the whole carrier must be removed.

There are two carriers, 3.08 and lower #, and 3.08 and higher # as I recall, you cannot change gears outside of those ranges ane re-use the carrier, ther is not enough room for the gears. I've run into this before.

As suggested by others, ther is really no reason to change the entire axle assembly just to get a LSD, it can be easily installed in the carrier you have, and what you have is more than good enough for the power for a stock engine up to a 302. The Power Trax may very well be the best bet for you, but they will NOT take the punnishment of high Tq manual transmissioned cars at the track, and they can be tricky in the snow/ice/rain because they are a "locking" differential system and not clutched which will allow some slip.

[jaywish]

Silver,

You have PM

Jay

[JACook]

There are two carriers, 3.08 and lower #, and 3.08 and higher # as I recall, you cannot change gears outside of those ranges ane re-use the carrier, ther is not enough room for the gears. I've run into this before. Can't say as I've ever personally run into this with an 8" or 9", but that's just my experience.
But I can say I've personally installed 4.11s in an 8" that originally came with 2.79s.

I do know some rears, like the GM 12-bolt and Dana 40/60 have different carriers depending
on ratio, but IIRC the split is up in the 4.11/4.56 range.