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Unread 05-23-2012, 02:34 PM   #1
Registered User
2000 TJ Wrangler 
Join Date: Oct 2011
Location: Chino, Ca
Posts: 93
Going from 3.73 to 4.56

Hi All,

I am going from 32's to 35" tires and will probably need to reagear on my 200 TJ 4.0 3spd Auto.

I currently have a D30 with a spartan locker and 3.73 in the front and a Dana 44 with the limited slip 3.73 in the rear.

Can anyone tell me exactly what I will need to get to go to 4.56 gears. I will probably have a shop do the work but I am looking to be educated here so that I know exactly what I am getting into.

I have read things like carrier break and Thick gears but it's all a mystery to me... Will I need a new locker or will mine work, do I need a carrier or thick gears...

Also is 4.56 the right choice for my setup and what would be the consequenses of just sticking with my 3.73's???

Thanks in advance

2000 Wrangler Sport 4.0L Auto, SYE, D44 3.73, 4.5" Lift, 15X10 MT Classic Lock, 35x12.50 Cooper Discoverer STT, Rampage Frame less top
Jeremywrags is offline   Reply With Quote
Unread 05-23-2012, 04:13 PM   #2
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2005 TJ Wrangler 
Join Date: May 2009
Location: Eaton Rapids, Michigan
Posts: 6,369
I believe the Spartan locker is a lunchbox locker and will work in either Dana carrier, but your 3.73 carrier will take 4.56 gears anyways, so it doesn't matter.

Your rear needs a 3.92+ carrier, or you can use thick cut gears and your current 3.73 and down carrier. The thick cut gears make up the difference between the 3 and 4 series carriers.

I feel that 4.56s would be a good choice. It would put you at almost 3000 RPM at 65 MPH. I run about 2800 RPM at 70 MPH. 3.73s isn't enough gear for the 35s; it would drop you out of the power band.
Jason is offline   Reply With Quote

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