Importance of "Breaking in" new Gears?

[BreBar21]

I was just making sure I was on the same page.

Do you just use a big ass pry bar to spread the case a little to slide in an extra .001"-.002" shim on the right side? Or did you fabricate some sort of turnbuckle with plates on the ends to bolt to the case to help spread? I'm curious.

OP, I would first take it around the block a couple times and see if they make any noise first before you drive it all the way home.

Closer to the latter. The guy that installed my gears the second time worked for Ford, so he had the Ford case spreader. IIRC, it was a square that bolted to the case and you cranked it to spread it apart.

 

[quick01snake]

Closer to the latter. The guy that installed my gears the second time worked for Ford, so he had the Ford case spreader. IIRC, it was a square that bolted to the case and you cranked it to spread it apart.

This. Google image search "ford IRS case spreader" and you will find plenty of pics.

Though I am not a gear installer myself, just have talked and learned a lot from very good rear end guys, but I think when you spread it you have to add equal amount of shims to each side to keep the position of the ring gear relative to the pinion gear the same.

 

[Stanger00]

This. Google image search "ford IRS case spreader" and you will find plenty of pics.

Though I am not a gear installer myself, just have talked and learned a lot from very good rear end guys, but I think when you spread it you have to add equal amount of shims to each side to keep the position of the ring gear relative to the pinion gear the same.

I figured if you setup without spreading the case for .004" back lash and then spread the case and add another shim it should bring you down to around .0025 - .003". You only need to change the shims on the other side if you are really out of spec if I read FRPP instructions correctly. I'll google those images.

Edit: I checked out some pictures and those are some hefty friggin tools to get that case to flex!

 

[CJK440]

fyi, the break in period is also for the new tapered roller bearings that are under preload, than just the gears themselves.

 

[Conrad B]

fyi, the break in period is also for the new tapered roller bearings that are under preload, than just the gears themselves.

I figured as much... Took the car quite a few miles now, and all seems well. On a completely unrelated note, where did you find the "COBRA" bumper inserts that appear to not be black or chrome? Also, do you know if they'll fit the '01 bumper?

Thanks

 

[Top Fuel Friday]

Drive normally for a couple of days then drop the hammer, there is a lot of prep that goes into making these gears strong from the factory. Your first driving cycles on them aren't really going to affect much one way or the other.