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28 or 31 ?


2002edgeplussupercab

2002edgeplussupercab

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How can I figure out if my differential has a 28 spline or a 31 spline input ?
 


adsm08

adsm08

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Axle tube sizes are the easy indicator. If they are straight the whole way it should be 31 spline, if they neck down a bit at the end they are 28.

If you don't have an FX4 you probably don't have a 31 spline, unless a PO swapped it in.
 
2002edgeplussupercab

2002edgeplussupercab

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Thanks. Mine is 7.5" open 3.73 in a 2002 4dr Scab Edge with 3.0 and 5 sp auto so it should be 28 spline ? Correct ?
 
adsm08

adsm08

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Oh yes, all the 7.5s were 28 spline.
 
2002edgeplussupercab

2002edgeplussupercab

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Thank You ! That helps emmensely !
 
adsm08

adsm08

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Also, you phrased the question wrong.

The input to the axle is the pinion gear, which doesn't have different spline counts on the 8.8. The axle shafts are what changed, and those are the output.
 
2002edgeplussupercab

2002edgeplussupercab

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Thanks for the education !
 
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