new carrier with 4.10s?
04-12-2009, 09:05 AM
#1
JK Freak
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new carrier with 4.10s?
i know ive seen it on here,about needing a new front carrier for my front d30 when going from 3.21s to 4.10s what is the reason for this??i searched it on here and didnt come up with anything, but i thought i saw somewhere the only reason why was because "the bolt holes on the 3.21 carrier were too small"but i thought that i also read that they could be drilled out!
does anyone have the proper answer to this thanks!!
does anyone have the proper answer to this thanks!!
04-12-2009, 12:00 PM
#2
JK Super Freak
Yes, you will require a new carrier for the front d30. MOST differentials make a split around the 3.73 and lower and 3.73 and higher, or 3.55 and lower and 3.55 and higher. The JK D44 however, due to it's thick ring gears I am told, allows you to maintain the 3.73 and lower carrier for all ring gear sizes.
Now to answer your question why? I believe it has something to do with the offset on the carrier and how the gear mounts to it, and if you were to use the wrong carrier with the wrong gear size you may not be able to run an appropriate mesh and setup of the gears would be out of wack. I believe I've heard of spacer rings being used to mount behind the ring gear to allow a numerically higher ratio to be used on a smaller carrier...but again, I'm not an expert on this. I think some people have tried accounting for the difference by making dramatic adjustments to the shims, but I've heard its next to impossible to adjust accordingly and premature bearing and/or gear failure can result.
Best to just get the new carrier, they're relatively inexpensive...or upgrade to a locker or LSD.
Now to answer your question why? I believe it has something to do with the offset on the carrier and how the gear mounts to it, and if you were to use the wrong carrier with the wrong gear size you may not be able to run an appropriate mesh and setup of the gears would be out of wack. I believe I've heard of spacer rings being used to mount behind the ring gear to allow a numerically higher ratio to be used on a smaller carrier...but again, I'm not an expert on this. I think some people have tried accounting for the difference by making dramatic adjustments to the shims, but I've heard its next to impossible to adjust accordingly and premature bearing and/or gear failure can result.
Best to just get the new carrier, they're relatively inexpensive...or upgrade to a locker or LSD.
04-12-2009, 12:41 PM
#3
JK Freak
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Right, it is because of the thickness of the ring gear. Shims will not make up for the difference, at least not correctly, and the meshing with the pinion gear will never be right.
It is worth noting that the JK carriers thicknesses are the opposite of the older versions, meaning that in the JK, the 4.10 ring gear is thicker that then higher (numerically lower) gears, and on the older verions, the numerically lower gears are the thicker ones.
So to install a 4.10 ring gear in a JK, you need a carrier from an older Dana 44 which had 3.21's.
Took me forever to figure this one out too....
It is worth noting that the JK carriers thicknesses are the opposite of the older versions, meaning that in the JK, the 4.10 ring gear is thicker that then higher (numerically lower) gears, and on the older verions, the numerically lower gears are the thicker ones.
So to install a 4.10 ring gear in a JK, you need a carrier from an older Dana 44 which had 3.21's.
Took me forever to figure this one out too....