Drop In Replacement Differential? Help Needed

[Swarzkopf]

Well, I burned out my traction-lok for the third time today while at the track. I'm sick of dealing with it.

I'm looking a DROP IN replacement differential; meaning an upgrade which retains the stock axle shafts, stock carrier, stock case, stock cover, ect.

I've got my eye on a "Powertrax Lock-Right Locker" from Summit for $349. This differential works with the 8.8" axle and with 28 spline axle shafts.

Here is Summit's write up on what vehicles it fits:

Axle Model Ford---- 8.8 in.
Axle Location------ Rear
Make-------------- FORD
Model------------- MUSTANG
Beginning Year---- 1982
Ending Year------- 2001
Stock Case Style-- Open case

I'm concerned about the "Stock Case Style- Open Case" line. Will I need to get a new case to accomodate this differential, as stock I have a traction-lok case?

Does anyone have any other recommendations for a replacement differential, affordably priced?

I know it would be better to upgrade to 31 spline axle shafts, but quite honestly, I want to run the car this year and a total rear axle upgrade is NOT in my budget, so please don't tell me to do this.

Feedback is appreciated. Thanks,
Shawn

 

[v6v8swap]

I was thinking that the Powertrax unit is to convert an open diff into something like a locker. So, if this is true, it wouldn't do you any good anyway. I do not have any experience with it personally, but I think I read that somewhere before.
It seems that Auburn and Eaton both get a lot of press, so both of them seem pretty reliable (more so than the stock Trac-Lok). Both of them would be more or less a drop in deal I would think.
That Eaton Ected looks really cool, but it's big bucks and a little more involved than a "regular" limited slip to install. It goes from a limited slip to a locker with the push of a button.
Sorry to hear about the troubles and good luck in your search.

 

[Swarzkopf]

Thanks for the feedback.

I was thinking that the Powertrax unit is to convert an open diff into something like a locker. So, if this is true, it wouldn't do you any good anyway. I do not have any experience with it personally, but I think I read that somewhere before.

Yeah, it's a true locker style differential, not a limited slip piece...anyone else, is he thinking the right thing by thinking that it won't work because I already have a limited slip piece?

It seems that Auburn and Eaton both get a lot of press, so both of them seem pretty reliable (more so than the stock Trac-Lok). Both of them would be more or less a drop in deal I would think.

Well, the other option I was looking at was an Eaton limited-slip type differential from Summit for $449...it's listed the same way, saying "Stock Case Style-- Open case". Quite honestly, I have no idea what this means.

I'm staying away from the Auburn- I've heard too many horror stories of the cones breaking.

Thanks for the feedback.

Anyone else?

 

[Swarzkopf]

Gonna give this a little bump...

Heeeeeeeeeelp meeee!

 

[wytstang]

Try Pming zenboy99 he's running an Eaton if memory serves my right. He may be able to give you some insight, that all I got but when you find out post the info please.

 

[Swarzkopf]

Thanks wytstang. I sent him a PM asking him to take a look at this thread.

 

[Swarzkopf]

Come on guys...

One more try.

 

[FORCED2DV8]

both Eaton and Auburn make drop in units that replace the trac lok, You can stay with your 28 spline axles, Giv ethem a call they will help you with what you need, Summit and Jegs carry these. You may be able to find a better deal online somewhere, You probably know this but the axles are usually the thing that breaks in the rear, You might consider rebuilding the trac lok with extra clutch paks, And try running with that ( If you havent already) Or shop the classifieds for a whole setup, axles and locker together.

 

[Swarzkopf]

Thanks Forced2dv8. Yeah, I rebuilt the traction-lok this winter with as many clutches as I could cram in, but it still only lasted one burnout...

I'll probably try Eaton at this point, unless anyone else cares to comment on the original Powertrax piece I asked about....

Thanks again.

 

[Killercanary]

Powertrax is the only drop in that I know of that will not require resetting the gear lash since it uses the stock diff. case.

A quick search netted me this...
http://www.powertrax.com/fordcarns.pdf
http://www.powertrax.com/faq.html

From that list it looks like you can use it in replacement of your trac lok. Basically it just involves removing the "guts" of your trac lok and replacing them with their stuff. I'd call them just to be sure before you spend your money, but I think it'll work fine for you.

Personally, I'd buy an $80 rebuild kit and just rebuild the clutches. It will cost a lot less than any other diff you will find and you won't be wasting your money on a 28 spline differential. Rebuild it now and buy a 31 spline later.

 

[Swarzkopf]

Great links! Thanks for the info.

 

[Killercanary]

Well, I typed too slow.

Why did it only last one burnout? There's something wrong if that is true. I ran my stocker at the track and on the street for YEARS and only had to rebuild it once. It functioned fine even when I replaced it with my eaton.

I have an eaton, and its a very good unit except for one VERY big drawback. The actual case of the unit has been known to fail, and it does so with quite a bit of frequency when used on HARD launches with sticky tires. The pin actually cuts through the case like a knife through butter. I didn't know this when I bought mine. Steelcity from SCS had one in his last '03 (the white one) and it blew apart into a million pieces on the starting like in a run against Mikeymustang. You may want to check with Steelcity too before buying the eaton. If all out drag racing ins't a conern then the eaton is a GREAT unit.

I do not like the auburns as they use a "cone" instead of clutches to lock both wheels, and when I was researching buying one MANY MANY people told me to stay away from them. They have been known to fail prematurely if your brunouts are not done properly with both tires in the water box, etc.

If I had to do it all over again I'd have bought a 31 spline traction lok like my dad runs in his '91GT. Its beefier than the 28 spline unit, its rebuildable, and I have yet to hear of anyone breaking on like the eatons. My dad launches HARD on his and has done so for a number of years and we haven't had to even replace the clutches yet.

 

[gmkillr]

I know you said not to do this but, its cheaper than you think.
Ford 31 spline trac-lok, totally rebuilt on ebay from reputable sellers go for $100 shipped all day long, hell, thats what im running in my car. And get your self a set of Superior Axles from Summit for $249. By time you add in fluid & stuff your looking under $400.

 

[Swarzkopf]

It seems to be hit or miss with the factory traction-loks- some guys run into the 10s on a stock piece, others, like me, have chronic issues at relatively low power levels.

Good friend of mine has a BONE STOCK '04 GT..he rebuilt his traction-lok once himself and had it done once professionally once and it's one wheelin' again. I've talked to a few others with these problems.

I'm going to try to find the right Powertrax model number at the right price. Then I'm going to pay someone to put it in. I absolutely DESPISE working on the rear axyle, and would be perfectly happy if I never had to smell differential fluid/friction modifier ever again.

 

[Leezure]

The powertrax will certainly be an easy install into the 8.8 and will provide you with a great deal more traction than the Tru track unit you are currently running. When you move to a locker from a limited slip set up (Tru track is just another limited slip) you will notice a huge difference in driveability. The locker will keep both axles turning at the same rate until the force from the tires (one turning faster than the other such as in a turn) causes the locker to disengage and snap back into place when the tires are both at the same speed.

This process is loud and unnerving at first but perfectly normal. You will experience increased tire wear from running a locker and you will need to be very careful on slick roads and powering out of turns. I run a powertrax no-slip on the rear of my Jeep. It is a bit more quiet than the normal powertrax locker and probably worth the extra money on a street car.

That being said... Understand that you will no longer have a smooth running rear end . You are moving into a race setup that no longer takes driveability into consideration.

I suggest riding in someone elses car with a locker before you go down this route.

The other way to go (and I highly recommend it) is to go with a selectable locker such as the Ected or ARB units which allow you to switch from locked to limited slip at the flip of a switch.

The choice is up to you but make sure you want to step up to a locker before you take the plunge.

Here is how the different diffs stack up from lowest to highest traction:

Open diff least amount of traction
Limited slip
Tru Track
lunchbox locker Powertrax
Detroit Locker
Spool Highest traction

 

[Leezure]

Good friend of mine has a BONE STOCK '04 GT..he rebuilt his traction-lok once himself and had it done once professionally once and it's one wheelin' again. I've talked to a few others with these problems.

Once again... Tru trak, Traction lok whatever Ford calls their diff setup is still only a limited slip. It's not a locker. This will happen with all limited slips.