[98formulals1]

hello everyone i just rebuilt the 4l60e in my 95 tahoe. now i am getting only 3rd gear starts. if i manually shift it into 1st or 2nd it will start in those gears. it has 1st 2nd and 3rd gear only if manually shifted. no od or tcc apply. i have read that these trucks have ignition switch problems. could this be it or is it something electronic in the trans? thanks for any help

[tnsmith10]

Originally Posted by 98formulals1

hello everyone i just rebuilt the 4l60e in my 95 tahoe. now i am getting only 3rd gear starts. if i manually shift it into 1st or 2nd it will start in those gears. it has 1st 2nd and 3rd gear only if manually shifted. no od or tcc apply. i have read that these trucks have ignition switch problems. could this be it or is it something electronic in the trans? thanks for any help

if it were a case where you have 3rd gear starts and could get manual 2nd then, id say your not getting 12v to the trans but, with it having manual low like you said, i dont believe that is the case here.
from here, id check for any dtc's in the system. if no codes stored, id say you have an assembly error or, if you have a scan tool with a live data stream, id make sure that the pcm is giving proper gear commands.
out of curiosity, what was the original failure?

[98formulals1]

the rear planetary was broke and the 3-4 clutch pack was fried

[motosyco]

There is a exhaust hole behind the 2 shift solenoids that needs to be enlarged or you get 3rd gear starts Ill dig out this tsb and post it for you the bigger hole is to let more oil exhaust when solenoid is off I see it in pretty much every second 4l60e that I build before that though there is an ignition problem to check with truck running check for power at the trans fuse in your dash if theres no power on either side you need a new ignition switch hope this helps and Ill dig up that tsb for you.

[98formulals1]

ok so i bought a code reader today and got the following codes:
59,66,67,81,82,83 any help would be much appreciated thank you

[hpete]

Quite a few codes, I would bet that you've got some wires pinched or not hooked up properly.

[tnsmith10]

Originally Posted by 98formulals1

ok so i bought a code reader today and got the following codes:
59,66,67,81,82,83 any help would be much appreciated thank you

its not likely (but possible) that you pinched the main harness between the block and bell housing because of how the harness is routed but, i have seen in the past where the builder (not knowingly) when putting the pan down has pinched a wire on the internal harness.
with the amount of codes you have, its either that or the main harness going to the trans is not hooked up or plugged in solidly.