th350 won't shift out of first
04-29-2010, 12:27 PM
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th350 won't shift out of first The other day I finally finish up the LSx swap in my Thirdgen and I go to drive it. The only problem is the trans won't shift out of first. It won't shift manually or in the Drive position. I have a Megashifter and I'm pretty sure the cable is adjusted properly. I put 11 quarts of fluid in the trans (I have a deep trans pan). I'm not sure why it won't shift out of first gear. Could it be the shifter cable? Low trans fluid? Bad transmission? Vacuum modulator? Governor?
04-29-2010, 12:47 PM
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First check the modulator & see if you are getting vacum.Check line for cracks if that is good pull governor see if the gear is good & see if the valve is stuck.Is the trans used or rebuilt?
04-29-2010, 12:59 PM
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It was supposedly rebuilt with a kit from Probuilt Automatics which includes a TransGo shift kit. I just put a new vacuum line on the modulator so that's good. It has an adjustable modulator. Could it be adjusted too high?
04-29-2010, 09:36 PM
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I traded a SBC roots supercharger for it. The guy I traded with owns a speed shop and built it to my specs for me. He's a nice guy, always responds to emails and calls and is generally helpful. I don't think he's trying to pull anything over on me. I'm thinking something isn't adjusted right, whether it be the vacuum modulator or the shift cable.
04-30-2010, 09:07 AM
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I will check the line for vacuum at the trans. I know it's connected to manifold vacuum because I connected the vacuum line to a nipple on the intake manifold. I'll adjust the modulator and see what that does. I got a new shifter cable and I'll install that and readjust the linkage. As a last resort I'll check out the governor. Hopefully I'm just not getting vacuum down to the modulator or it needs to be adjusted.
05-04-2010, 12:31 AM
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I installed the new shift cable today and checked out the governor and the modulator. Both the governor and the modulator are fine, and I'm getting vacuum at the modulator. I haven't had a chance to drive it yet. I'll probably do that tomorrow after work. We'll see what happens!
