3.42 Gears and TruTrac

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,065
4,735
113
Phoenix Az
factory gears always setup the best imho but ive never had much issue with Yukons. i just setup a set of used yukon 5.13 gears for my ford 8.8 going from stock 3.73. only needed .004 more pinion depth and off set the ring gear to the driver side .0012 from factory shims. pattern is dead nuts center and great depth into the tooth. to get a used gear to setup like that is hard to come by.
 

ikeG

Oughta Know Better
Apr 19, 2011
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Western PA
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Any noticeable differences between the Yukon gears vs going back with the AAM gears - as far as quality/durability and gear set-up?

I've run the Yukon 4.56 and 3.73 gears in other set-ups. Was thinking about getting AAM if I decide to do this swap.
AAM are stronger. Sled pullers have proven this but unfortunately aam has discontinued the ratios most commonly used in pulling. I think they still make 3.42 3.73 & 4.10

Sent from my XT1585 using Tapatalk
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,065
4,735
113
Phoenix Az
AAM are stronger. Sled pullers have proven this but unfortunately aam has discontinued the ratios most commonly used in pulling. I think they still make 3.42 3.73 & 4.10

Sent from my XT1585 using Tapatalk

i dont think strength will be the issue in a 3.42. pinion is getting larger and still plenty of meat on the ring gear. under 3.0 might be an issue. i could definitely see where the AAM are stronger in a sled pull in the 4.56 gear ratios.
 

tanlly

diesel enthusiast
Mar 13, 2010
36
0
0
pennsylvania
I don’t really post much but I’ve decided to take on this project of 3.42 ratio change. I successfully replace the rear axle ratio. I’m and struggling with my front diff figment. Does anyone have any suggestions? If I need to I can start my own thread. I don’t mean to hijack this thread.
 

tanlly

diesel enthusiast
Mar 13, 2010
36
0
0
pennsylvania
I setup the pinion in the housing to proper spec with no pinion shims installed. I have my passenger side adjust backed all the way out. Set the carrier into the drivers side housing, set the drivers side housing down on the other case half, I tighten bolts down to bring case halves together evenly and I get to about a 1/16 inch gap and my pinion gets outrageously tight to where I can’t spin the pinion with the yoke on it by hand. I can attach photos
 

tanlly

diesel enthusiast
Mar 13, 2010
36
0
0
pennsylvania
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tanlly

diesel enthusiast
Mar 13, 2010
36
0
0
pennsylvania
I can loosen it but it seems to only allow the carrier to twist and become offset in the housing. So to sum it up it does not allow me to completely bring the housing together nor does it free up the pinion.