Will a Dana 44 4.09 gear fit in a 3.31 axle?


From: DJLevesque@webtv.net (David Levesque)
 I think a 4- series gear will only fit in a 3.73 on up housing??? Or was
it 3.90 on up housing?? Any way, the bigger number gears fit one housing 
and the small number gears fit the other. The thickness of the ring gear
was different because of the different tooth counts on the different
pinions. The 4.55's used a thick ring gear because the pinion was small 
diam.  The 3.07 had a big pinion and a thinner ring gear. I know that 
some aftermarket companies started making some special ring gears of 
different thicknesses to allow fitting steeper gears into the more common
housings (A 3.31 housing is much much more common than a 4.55) , but with 
the usual gears out there, I'm afraid the housing you have will take only
tall gears (3.07, 3.331, 3.54 , etc) 

From: "Fred Buchholz"
It will fit in a Dana 44, 3:31 axle if you change the carrier assembly as
well. 3:07 to 3:73 use one carrier ass'ly, 4:09 and up another. 

From: John Kunkel
Dan Giblin Yes and no. The gears will fit but will require a different
differential case. One case was used for 3.73 and numerically lower and
another for 4.09 and numerically higher. John 

From: daytona62@mindspring.com 
John, Glad you said this. In the "44" there were 3-series and 4-series 
differentials. The difference being the thickness of the flange where
the ring gear mounts. The 4-series had a thicker flange to space the ring 
toward the smaller diameter pinion. If Dan is thinking of changing the 
entire diff he is OK. If he just wants to put the 4:09's on a 3-series 
carrier he will definitely have troubles. There simply will be no room.
 Lee

From: tedharbit@aol.com (TedHarbit)
I remember
about 37 years ago, I changed gears in the Chicken Hawk from 3.54 to 
4.55 and used a 1/4" spacer plate with the ring gear and it worked fine 
as long as I would keep the ring gear bolts tight. 
One more comment forgot about rear end gears. As was mentioned, 3.73 
and lower numbers take same carrier, but one number before the 4.09 
and up is the 3.92.