Ramaci12

Hey guys I have a 2001 Silverado cammed with 4:56 gears. Has a 4l60e transmission and transgo hd2 shift kit. The kit came with a 1-2 shift valve that allows you to hold 1st gear up to any speed without shifting out. Put it in cause I thought why not. The other day I was doing burnouts and donuts on pavement with the truck in Manual 1 and I did not shift out. Truck bounced of the rev limiter like crazy and I did this about 3 different times. Had good ride until the next day my trans started to skip second gear and go into third. Even if I try manually shifting into second it won't. And if I put the pedal to the floor it immediately hits the rev limiter. I looked up common problems with the 4l60e and this does not come up. I dropped the pan and fluid is fine and no major metal on the magnet. Hooked it up to a snap on scan tool and the truck thinks it's in second gear when it's actually still in first. I'm thinking that the new shift valve I put in broke but I'm not sure. Any ideas?
Thanks

GMCSIERRA5.3

probably broke the band anchor..if you have no second theres no 4th either

bbond105

Do you have 4th gear?

Ramaci12

I have 4 gear still. The truck drives fine except that it skips second.

mrvedit

I don't understand what hydraulic mod the HD2 "Gear Command" shift valve performs; I've never installed it as it sounds like a dumb idea as it would allow a (unintended) manual downshift into an over-rev condition. Even without it, my trans won't upshift past the selected gear.

Perhaps you should try re-installing the stock 1-2 shift valve.

My only other suggestion is to check the servo end play - while holding a ruler next to the servo cover, press on it with a crow bar and estimate how much it moves.
End play much past .175 (3/16") indicates a worn band; usually 2nd gear then starts to slip.

Ramaci12

I called transgo and they said with with the truck in neural and tires off the ground press on the servo while someone spins the driveshaft and it should stop it. I did this and my friend was still able to turn it but it was a lot harder almost to the point where he couldnt turn it. Transgo said I need a longer pin then. I don't understand why I would need a longer pin if it drove fine before.

mrvedit

The band was well worn before you had your fun.

Here are some related threads that might be useful to you.

Lengthened Servo Pin:
https://ls1tech.com/forums/automatic...t-trouble.html
https://ls1tech.com/forums/automatic...-gear-all.html
https://ls1tech.com/forums/automatic...ckup-help.html
Worked:
https://ls1tech.com/forums/automatic...cond-only.html
https://ls1tech.com/forums/automatic...e-2-fixed.html
https://ls1tech.com/forums/automatic...-4th-gear.html


No 2nd Gear:
https://ls1tech.com/forums/automatic...t-trouble.html
https://ls1tech.com/forums/automatic...-my-4l60e.html