Different gear carriers for gears over a certain ratio?

[Ryan87LX]

Every once in a while when I'm searching about differentials on the net, I'll see a reference about carriers such as 'for rear gears up to 4.10' or 'for rear gears above 4.30'

Why is this? I always thought I could use my carrier that is currently equipped with 3.55 gears, even if I had to install 5.13. Am I missing something? Is this a Chevy/Dodge thing perhaps?

[TheUnforgiven]

there is a carrier break after 4.10 i believe that use a different carrier. why i don't know. never looked into it. just read a little about it here.

[4DI2D]

You can only put so many teeth on a ring and then you need a larger ring. They can't just put smaller teeth on due to strength requirements.

[CJREX]

It depends on the axle.

For the Bronco D44, the carrier break is at 3.92.

The carrier for 3.73 gears has a lower mounting point for the ring gear than the carrier for 4.10 gears. As gear ratios go up the ring gear gets thicker. By moving the mounting point closer to the pinion, you don't need such a thick ring gear.

The 8.8 doesn't have a carrier break.

[f150inline]

for the 8.8 you will need a notched crosspin if you go with 4.56s and up.

[Moze]

Originally Posted by CJREX

It depends on the axle.

For the Bronco D44, the carrier break is at 3.92.

The carrier for 3.73 gears has a lower mounting point for the ring gear than the carrier for 4.10 gears. As gear ratios go up the ring gear gets thicker. By moving the mounting point closer to the pinion, you don't need such a thick ring gear.

The 8.8 doesn't have a carrier break.

If I got a d50 with 4.10s then i wouldnt need to change carries to go to 4.56? Also same question for a 9in pumpkin with 4.10s, from factory, if i find one.

[CJREX]

The D50 has the same carrier break as D44, so yes 4.56 gears will work on one that had 4.10.

The 9" does not have a carrier break so 4.56 will work there too.

[Ryan87LX]

Oh,I see.

So, it's safe to pick up a locker for my 8.8, but leave the front LSD until I change gears from 3.55 to something bigger.

That makes a lot of sense. Thanks!

[CJREX]

Choose your 8.8 locker properly.

If your 8.8 has a factory L/S (likely if the front has it), most of the drop in lockers (Spartan, Aussie, Lock Right, etc) won't fit.

I've read that there are some made for the L/S carrier but they are expensive to the point of being near a Detroit, which is better than any drop in locker because it replaces the 8.8 carrier.

If your 8.8 is an open carrier you have many options. My personal drop in preference is the Aussie. I had one in my CJ7 and it worked great.

[Ryan87LX]

I'm open front and rear right now, with 3.55.

I was thinking about picking up a Powertrax for the rear 8.8, and then looking for a factory traction-lok to put in the front.

However, I think I'll leave the front open, unless I could find a smoking deal on one.

Really appreciate all of the info.

[Moze]

Originally Posted by CJREX

The D50 has the same carrier break as D44, so yes 4.56 gears will work on one that had 4.10.

The 9" does not have a carrier break so 4.56 will work there too.

Thanks thats good info