Centurion96

If Ford is using the same 31 spline 8.8 LS carrier it used in the Broncos and F-150s then I'm sc+&#^d. I grenaded both my '88 Bronco LS rear end and my '96 Centurion LS rear end in the same manor. Here are some photos of the '96. The white chalk marks the thickness of the tapered end opposite the ring gear. There is not much steel there and the problem is compounded by the sharp 90 degree cuts for the dog eared clutches. Those sharp cuts are an excellent place for cracks to start and when the rear end goes it opens up like a clam shell at that end.

Pardon the rust as these parts sat out in the weather for a couple of months before I got a digital camera.

BB

06GT4RAD

The Factory LS unit is actually a pretty weak unit overall. The case is very thin. I myself plan on going with the Eaton LS. You can also by the upgraded spring kit and bump them to 800Lb. I run one in my F150 4x4 and it has held up like a champ even with running the larger tires.

Richard

metroplex

The 8.8" carriers have worked fine for the past 20+ years unless you really abuse them.

I've heard lots of good things about the Toyoda/Zexel/Gleason (whoever owns the patent now) Torsen differential (the original). I got burned badly by TracTech (or whoever owns TrueTrac) with my grenaded 8.8" trueTrac and won't ever buy another TrueTrac.

MrClean

the deal is that I drive my car up to ~105 every day, and I have a vibration at those speeds...so I'm having the Spydershaft balanced on Friday to see if that's the source of the problem...if it isn't, then it could be tires (yeah, I'm gonna go through a rotation to eliminate that from the mix), or it could be the LSD. If the DS and tires/rims aren't the problem, then its likely the rear end/LSD, so that is why I would spend the dough on the Torsen or Truetrac (sounds like I'll go FRPP Torsen T-2 from what Metroplex is saying) to eliminate the problem...or I might just take the balancing sheet back to the stealership and tell them to fix the rear end vibes, although they're likely to say they can't test it at 105 mph or some bull like that.
Or, I could just re-install the stock DS, which is a noodle/damper, and which masks the rear end problem, and do w/o the Spydershaft.

Centurion96

With having to deal with Ford's Trac Lok 8.8 in my 4x4s for over 20 years I personally think it's a piece of junk. I don't abuse my vehicles, I'm well within the stated towing capacity when pulling my boats. All of my 4 wheeling consists of sand trails or algae covered boat ramps at low tide. No mudding and no rock climbing. I've grenaded two Trac Locs in the exact same manor. I am not alone with this assessment, several others on my Bronco forums have experienced similar problems.

I don't have any problems with the 8.8 open diff carrier, it's what Ford did to that carrier to accept the passenger side clutch plates that frustrate me. Having the same carrier in my Mustang bothers me, especially considering that I'm leaning towards FI on this car.

BB

metroplex

The loads applied to the carrier are kind of different when you're towing a heavy load or off-roading in a heavy vehicle. The Mustang weighs 3450 lb and shouldn't be towing anything, and is driven on nice paved roads and tracks. Short of dumping your clutch at 6000 RPM w/ drag slicks behind a forced induction motor, the stock Traction-Lok will take quite a bit of abuse. I have yet to hear of any 8.8" 28/31 spline T-lok carriers grenading in the Trilogy Marauders or the supercharged Crown Vics. I snapped every side bolt on my 8.8" TrueTrac in my 15 second Crown Vic using street tires and the 4R70W.

Centurion96

Okay but I'll be keeping my fingers crossed.

BB

pville piper

You're my hero!

LAK3RS

I've heard nothing but great things about the Tru Trac. IMO, Don_w has who knows how many runs on his and he's putting out quite a bit of power with his Kenne Bell. Plus it's a dd as well!

06GT4RAD

The carrier for the Trac Lok is Junk as Centurion said. I also have eaten a few of the 8.8's in my F150's. One of the reasons why Ford stepped up to the 9.75" Rear Ends with the 5.4L Engine the 8.8 cannot handle the added loads And it is most likely the cause of the vibration issue. And as they say" One Man's trash is another man's treasure"

Richard

bob

Your saying the 8.8 can't handle the current Mustang???????????

metroplex

Our mustangs aren't 4x4 trucks. Different loads, different applications.

Our 2003 E-250 has a Dana-60 (9.75") rear-end, but it also weighs 5500 lb and is a 8800 GVW vehicle with Load Range E tires and wheels (8 lugnuts), comparable to those used on the HMMWV.

The S197 GT w/ manual is 3450 lb and doesn't tow anything, nor should it be off-roaded in stock configuration. The wheels are rather flimsy compared to Load Range E wheels, and the tires certainly cannot handle the same load.

Essentially a 5.4L 2V/3V/4V truck with a Dana-60 is apples to oranges compared to any Mustang.

Now, if you had drag slicks or drag radials on a 400+ hp Stang and did 7k RPM clutch dumps (significant driveline shock), you're likely to grenade weaker differentials. The PowerTraxx units are known to grenade one after another in such an application but work just fine on off-roading trucks/4x4s.

I hear what you are saying though - the stock 31 spline units will sacrifice some material to fit in those splines. However, the 05-up Police Interceptors all have 31 spline 8.8" carriers and axles and haven't grenaded any Traction-Lok carriers. I'm sure you can find someone who has even grenaded an open 8.8" carrier. The stock LSD carriers are not bulletproof but offer a lot of bang for the buck.

bryanthomas

MrClean

After taking the Spyder to a driveline specialist, and having the balance checked (it's good), I rotated the Spyder 180º and the murmur is greatly reduced and threshold is raised...so I'm happy w/it...I was gonna do the 4.10's next week (my wife's bday present), but decided not too...it would raise the DS speed at the same vehicle speed, and I don't want to mess with what is an ok situation.

I'm gonna wait until the warranty wears out of the TracLoc grenades to make the change to a Torsen T-2, and for the 4.10's. The stealership Serviuce Manager said he's work with me on the rear end vibes even with the aftermarket DS...especially now that I can prove it's balanced (I got documentation from the driveline shop).

BTW, he used the Spicer J3253 critical speed claculator to calc the critical speed for the Spyder: 5800 DS RPM (132 mph with 3.55's, 114 mph with 4.10's)

MrClean

Are you married dude?

Hey what gives? Your profile says you joined the forum in September 2006 and only have 15 posts to your name? Have you been just lurking?

kevinb120

They are holding up fine with modded GT500's right now, So its currently #459 on my things I worry about on my car list driving a CAI GT. Its right between peanut butter in the cd player and scratches on the jack handle on the list.

EDIT: label flaking off the baggie with the wheel lock key just bumped it one more down.

MrClean

theedge67

I'm with you on this one. I don't see the need for a new rear end unless you intend on doing more drag racing than daily driving. Like Kevin said, if the GT500's are doing fine with the 8.8 Limited Slip, then I don't see how people think they are weak. Just don't do any 6,500rpm clutch drops...you'll be fine.

06GT4RAD

I am not saying that the 8.8" overall is weak. I am strictly referring to the LS unit. And you all can sit here and argue about it all you want it isn't going to change my opinion of them. The 9.75" Is way to large to stick under the Mustang so I do not see that Ford has much of a choice other than the 8.8" They at least beefed it up to a 31 Spline Axles which i think will help greatly but that may have weakened the LS Carrier even more.

I am not bashing the 8.8 it hasn't been around as long as it has by being and inferior axle but what they do to the LS housing to get it to fit the clutches is not a good thing and it makes the wals very thin. Unless they have changed that method.


Richard

theedge67

So...if the walls of the unit are thin, what does that mean? How does that make it weak? I'm not arguing, I'm just failing to see how that matters. Granted I'm no expert on gears. I know engines, not gears.