What caused this Break?!

[VortecJeep]

Any ideas on what caused this break (crack at the pinion)? Ford 9", spool, 4.56 gears in my TJ with the 4.0. I was riding URE, but don't recall any major hit or noise. Sorry for the poor pic, right now my cell phone is the best camera I have.

 

[RenegadeT]

is that milk chocolaty stuff supposed to be gear oil?

 

[Jeff B]

to much pinion preload???

 

[VortecJeep]

is that milk chocolaty stuff supposed to be gear oil?

The gear oil looked fine when I drained it, I think the way it looks in the picture is because I was having my wife hold a work light over it while I took the picture.

 

[Yay!Gurrr]

What do the pinion bearings look like ?
Were you running a solid spacer ?
How old is the case ?

Id say pinion preload went away allowing the pinion to walk around.

What do the pinion support and bolts look like ?
Did you take a hard hit on the pinion/yoke or drive shaft ?

 

[MarsFab]

Is there any in or out play in the pinion? My guess would be that the pinion bearing went bad and let the pinion gear climb the ring gear. Can you take a close up of the crack from the same angle you took the first one. It looks like the inner pinion bearing is pushed in some.

 

[smittybronco4]

im not sure but i have busted about 4 or 5 cases like that ranging from a stock setup to a setup i put in...

 

[rock-lucky]

I have broken a case like that as well. My issue was the ring gear came into contact cith the pion bearing support under heavy torque load situations. I had everything set up right but it would still deflect. I bought a nodular 9+ by currie with a daytona pinion support and it solved my problems till I sold the jeep.

 

[VortecJeep]

Thanks for the info. I didn't have time to look at it any closer last night. I'll do some further inspections on it tonight and try to get some better pics.

 

[4x4K5]

If you look closely just below the crack, there is a silver spot amongst the brown area, that looks like the ring gear kicked it pretty good. Being that it is spooled, the carrier might have moved over under stress from turning or something and hit the spot by the crack..... not quite sure though

 

[Cperry]

it happens could have been deflection could have been contact do to deflection. an aftermarket case will fix it. the case is 30 years old or more she was tired. we can build you a sick 9" with a five year warranty.

 

[strange1]

the case is 30 years old or more she was tired.

true

 

[VortecJeep]

it happens could have been deflection could have been contact do to deflection. an aftermarket case will fix it. the case is 30 years old or more she was tired. we can build you a sick 9" with a five year warranty.

Chase, you've always done me right with everything else I've gotten from you. I'm going to take the R&P to a mechanic I know and ask him if the gears look ok or if I should replace them. Once I know that, I'll be contacting you either for an empty third member or the whole thing. It was driven for probably about 30 miles like that before I took the driveshaft out, then about another 15 miles in front wheel drive with no rear driveshaft.

 

[WARRIORWELDING]

this is the only real weakness that 9's have, its more common on higher horsepower and torque applications. go with chase on this one, a nodular case and a daytona pinion support and she'll be bullit proof (pending your axle spline count)

 

[VortecJeep]

this is the only real weakness that 9's have, its more common on higher horsepower and torque applications. go with chase on this one, a nodular case and a daytona pinion support and she'll be bullit proof (pending your axle spline count)

Yep, I'm going with Chase. It is 31 spline.

 

[Metto]

we have billet steel pinion supports as well, they take rock hits better than the aluminum one