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01 monttana 4t65 actuall gear ratio


l67ss

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i checked on a few fb pages b4 i l26 swapped....they all said an 01 montana had 3.29 gearing. do the swap and now the cel is still lit and the incorrect ratio code is still popping up. also av rpms at a given cruise speed ar 150-200 rpms higher than my olds trans(4t65 from an 01 monte ss that i kno had 3.29s) so what ratio does it actually have? i was guessing 3.43. and btw my pcm is from a 98 monte z34(l36/4t65 w/3.29) thanks

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what tag is on the new trans? if it's 1BCB, it should have a 3.29 final drive and a 35/35 chainset(so 3.29 overall).

 

the incorrect ratio code could be disabling 4th gear or TCC, which may explain the higher RPM observed. depending on what converter you're using could play into it as well.

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what tag is on the new trans? if it's 1BCB, it should have a 3.29 final drive and a 35/35 chainset(so 3.29 overall).

 

the incorrect ratio code could be disabling 4th gear or TCC, which may explain the higher RPM observed. depending on what converter you're using could play into it as well.

overdrive is working...unsure of tcc. didnt wanna use the 3400 tq converter so i used one from an l36 99 bonneville. i also didnt trust the converter from the old trans, it either had a bad pump or converter...seemed kinda dicey
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I checked one thought: both the transport and a 99 L36 bonneville use the same converter with the same K-factor (stall speed)

 

It is either a wiring difference, a bad trans, or a wrong trans install in the donor.

 

there are no final drive ratio 4t65e higher than 3.29, but it could be a used trans that has a lower gear ratio with the apparent higher gear feel caused by not reaching the proper overdrive range. basically what the tuned pcm I got at the meet did, it didn't like my trans. :(

 

info:

http://www.gmtuners.com/pda/4T65E-ID.htm

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only thing i can think of had to remove and rotate the vss(trans off a 3400 getting bolted to a 3800, wouldahit th intermediate shaft bracket otherwise).......speedo is dead on tho.....

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  • 2 weeks later...

gear ratio just magically dissapeared yesterday...down to 5 codes...all for egr and downstream o2...and i kno how to fix those. install the o2 and actually hook up the egr lol

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