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Discussion Starter #1
Whats up all! Just put 285's on my truck, went into tcm and put adjustment in for speedo. shifts great but when i have tow mode on it shifts fine from 1st to 2cnd, the rest of the shifts dont happen till about 2800-2900 rpm dont remember it being that high before. Any info will be appreciated!
 

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Discussion Starter #2
anyone?
 

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So you changed the tire size in the TCM, therefore changing shift points?

I've never touched mine, just changed tire size in the ECM.

Remember by changing tire size you have in effect changed the gear ratio as well.
 

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Discussion Starter #4
yes i changed it in the tcm, when i went to 285's the tranny seemed to shift quicker< thats when i changed it in the tcm. shifts great holds shifts a little longer but in tow haul mode seems to shift at a higher rpm then it ever did before. It shifts at about 2800-2900 rpm. If thats a ok range im gonna leave it.
 
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