On saturday at the track I broke the passanger side axle cup (the part of the axle that goes into the diff and bolts to the "real" axle.

Does anyone make stronger versions of these?

Who else has broken these or other drivetrain bits? I thought the TII drivetrain was pretty stout but after a week of driving with real power my transmission is starting to make noise and I broke this... I'm thinking I'm going to be breaking a lot.

 

how much power are you putting out that'll make a big difference

 

well sure it will. No idea on power numbers, was running 18PSI and ran a 11.66@120mph
but obviously I'm not going to be making less power to make them last longer, I need stronger parts!

 

http://www.rotaryextreme.com/fcdrivetrain.html

I think these might be available elsewhere too.

 

those are awesome, but that's not the part I broke : (

 

considered just swapping in another S4 diff? Although they're hard to come by where we are it might be an option to explore...

But personally I don't think I've seen those particular pieces (the cups with the bolt studs in them that the 1/2 shafts bolt to, right?) in upgraded form.

Maybe a driveshaft/machine shop can re-produce them with a different material?

 

Yeah just the cup broke. Sheared right where the splines end. About 1.5" thick metal.

I am considering drawing them up in CAD and having them made in a sturdier form.

the diff itself is fine, same with the axle. though apparently worn out because I'd think that with limited slip it would still move the car with one broken axle.

 

mmmaybe, but correct me if Im wrong here, but there is a point where the diff will slip. I.e. going around a corner at low speed, the outer wheel moves faster than the inner...with that in mind - wouldn't it make sense that with ZERO resistance on the side with the busted cup that the side still intact would slip? I could be wrong, but the diff may be fine....

 

yeah I think that maybe the diff is OK,.

I've looked around a bit but can't find these parts anywhere!

Even the dealer says they can't get them, WTF.

 

running those numbers you will likely be breaking the diff itself soon. consider upgrading the whole axle assembly.

 

I called the other local dealership (they're a bit further away but less retarded) and they said there are several in stock in the US that they can get to me, $96 later and I have a new stock one coming with a 1 year warranty. I still need stronger ones though

 

your diff housing will soon to be going out. like i said...you can only push the thing so hard before other things are going to blow up.


don't waste your time or money trying engineer new ways of holding the carrier to the case, the power will find new ways of escaping one way or another. your time/money will be better spent on a whole new upgraded rear end.

 

there isn't one though really!

The supra diffs are pretty tough apparently but mount completely differently. Same with the mustang IRS setup.

 

bah - throw a solid Ford 9" in there man!! lol

 

i was sure there was a company or 2 that made complete upgrade units.

 

I have an FB coming for that.

Ford 8.8" Swaps in very nicely and is like 50LB lighter than the 9" and just as strong.

 

When you get the new part you could possible have it cryo hardened. That might extend the life some.