Broken rearend, pictures inside

[mr. anderson]

broke the car on the first of the month on a test and tune, finally tore into it today, here's the snapshot. stock 3.73's, (has the upgraded diff stock ,2011 brembo 3.73 package). I've beefed up the rear end with a che axle brace and the FRPP rearend girdle with bearing supports. I was running MT ET drag 28x10S 15's doing 5k RPM launches. I got more than I thought I would out of the rear end. the only thing I hadn't upgraded was the diff and the transmission. everything else is beefed up in the drive line. 1pc ds, and a McLeod RXT clutch.

here's the results:

notice the weight reduction mod to the pinion gear:

spider gears and carrier:

other side of the carrier and spider gears:

the valley of the dead spider gears:

only good thing about this is the axles are still good.

 

[fdjizm]

Mine was on it's way there when I swapped it for a trutrac... lol

Don't bother getting another stock diff!

 

[mr. anderson]

not gonna. truetrac ordered today

 

[skwerl]

Non synthetic oil for the TrueTrac, I used Lucas. That stuff is thick as pig snot.

 

[mr. anderson]

any friction modifier needed or is it just gear oil? I guess just gear oil since there are no clutches huh?

 

[skwerl]

Correct, no clutches and no modifier.

 

[Sharad]

That's scary stuff. Sean Kelley just did that to his S197 this weekend too.

 

[wbt]

Broke it with the girdle and axle brace on the car?

 

[mr. anderson]

yup, looked to be the spider gears gave out and took out the pinion gear with the shards or the other way around, but it's more likely the little gears gave out first.

happened at the line on launch. first run I launched at 4500 rpm and she bogged a little, so the last run I launched at 5000 rpm and side stepped the clutch and gave it gas at the same time. front end lifted and crunch, crunch, crunch, that's all she wrote.

 

[wbt]

yup, looked to be the spider gears gave out and took out the pinion gear with the shards or the other way around, but it's more likely the little gears gave out first.

happened at the line on launch. first run I launched at 4500 rpm and she bogged a little, so the last run I launched at 5000 rpm and side stepped the clutch and gave it gas at the same time. front end lifted and crunch, crunch, crunch, that's all she wrote.

Damn..... Generally deflection is what kills the spider gears. I would expect the girdle and brace would minimize it. On my 2011 I broke the driver side axle in a similar situation. When I pulled everything apart the differential was in-tact. Cleaned the housing out, replaced the axle and went on down the road. I was running the CHE brace and a girdle out back.

 

[mr. anderson]

cool, that video could be a duplicate of my run when it broke. exactly how I described it. except mine was the diff. did you put the same stock axle back in it, or did you upgrade those?

 

[wbt]

cool, that video could be a duplicate of my run when it broke. exactly how I described it. except mine was the diff. did you put the same stock axle back in it, or did you upgrade those?

Ten Factory axles. Not sure if they are really any better than stock. A month later I traded that car for my 2012 which is also running Ten Factory axles.
http://www.tenfactory.com/

 

[mr. anderson]

finally got to tearing it apart since I got nothing better to do today:

axle gears, only one was damaged:

chunk out off the diff:

pinion gear tooth, crushed and broken:

spider gear reassembled:

apart:

[/QUOTE]

 

[philkilla]

ouch

 

[Falkinman]

I got lucky and cought mine before major damage. I only had two tine chips from one spider gear and lots of hairline cracks. Yup it probably would have shattered like yours the next time i launched it at 6,000. Turns out mine was caused by a bent axle housing. I ordered a detroit locker and I'm straightening my axle housing. I will be welding my axle tubes and installing a CHE brace as well.

 

[Sharad]

Ugh. I don't know why I look at these threads. Axle carnage pics are as bad as that old "faces of death" website was. The pics make my stomach turn.



Oh well, opportunity for upgrades I guess! So it seems like the cool kids are using Truetrac diffs? Is that a drag strip thing, or will it work well for cornering too?

 

[fdjizm]

I know plenty of guys that go to the track with a trutrac for years now.
Mines been holding up fine as well. I think I've only ever heard of 2 incidents where a truetrac broke in a mustang.

 

[Sharad]

I know plenty of guys that go to the track with a trutrac for years now.
Mines been holding up fine as well. I think I've only ever heard of 2 incidents where a truetrac broke in a mustang.

You mean they're running open track, like roadcourse? If so, I should probably go ahead and order the diff before I pull the axle housing to have the tubes welded. Might as well upgrade the diff while the guts are out, right?

 

[Falkinman]

Do some more research before you buy a truetrac for drag racing. They are definitely not made for drag racing although alot of guys use them for it and they do last longer than stock differentials. Truetracs are really a better all around differential made for street and road racing. If you plan on drag racing seriously then you will want a detroit locker like I bought.

 

[Sharad]

I use a Strange Engineering spool in my street/strip car. It works well, and it's light.