c6 stuck in first gear?

[madrockwyo]

I am posting this for a friend who just had a used c6 installed in his 80's bronco by a retired master mechanic, but now the trans is stuck in first and the mechanic has not seen this before. what could cause a c6 to not shigt out of 1st?

[Lazy K]

I`m not an expert but my guesses would be kickdown rod not fitted right or no vacuum to the modulator or bad modulator.

[jimmyjoejr]

My C4 had same problem after a friend took the pan and valve body off for inspection, turns out he didn't line up the gear selector linkage correctly when installing the valve body causing it to not shift out of first gear. It was a simple fix, just remove the pan and valve body and make sure the linkage is lined up. Hope that helps!