Turbo 350 won't shift out of 1st - The 1947 - Present Chevrolet & GMC Truck Message Board Network

csb#356 · 08-10-2009, 11:06 PM

Ok, ive been having this problem for a while. I replaced the vacuum modulator then found out that the transfer case was in low. Put the t-case back in high but now it still will not shift. I tried shifting it manually but couldn't get it to but I don't know how high you have to rev before you try and shift. Someone told be that there is a little rod that goes into the transmission behind the modulator but when I replaced it I didn't see one. does this sound like a vacuum problem or a governor problem. Please help!

68 TT · 08-11-2009, 07:58 AM

Usually if the trans won't shift out of first the vacuum modulator is not getting any vacuum from the engine. Make sure the line is connected at both ends. It is easy to knock it off and not realize you did it.

**old Rusty C10** · 08-11-2009, 08:26 AM

as long as the modulator and the line is good, ive had them blow where you lose everything but first so it may be time for a trans

Chlsnk · 08-11-2009, 10:47 AM

I am having the exact same problem except mine is 2wd . Were do the vacume lines run to?

csb#356 · 08-11-2009, 01:41 PM

The vacuum lines run to the back of the transmission right above the pan. Passenger side. Well Im gonna check out the governor gear on mine because Im not ready to give up on this transmission yet.

08-10-2009, 11:06 PM	#1
csb#356 Registered User Join Date: May 2009 Location: Pinehurst, Idaho Posts: 311	Turbo 350 won't shift out of 1st Ok, ive been having this problem for a while. I replaced the vacuum modulator then found out that the transfer case was in low. Put the t-case back in high but now it still will not shift. I tried shifting it manually but couldn't get it to but I don't know how high you have to rev before you try and shift. Someone told be that there is a little rod that goes into the transmission behind the modulator but when I replaced it I didn't see one. does this sound like a vacuum problem or a governor problem. Please help!

08-11-2009, 07:58 AM	#2
68 TT Still plays with trucks Join Date: Jul 2009 Location: Spokane, WA Posts: 3,556	Re: Turbo 350 won't shift out of 1st Usually if the trans won't shift out of first the vacuum modulator is not getting any vacuum from the engine. Make sure the line is connected at both ends. It is easy to knock it off and not realize you did it.

08-11-2009, 10:47 AM	#4
Chlsnk Registered User Join Date: Jan 2009 Location: Kansas city Posts: 756	Re: Turbo 350 won't shift out of 1st I am having the exact same problem except mine is 2wd . Were do the vacume lines run to?

08-11-2009, 01:41 PM	#5
csb#356 Registered User Join Date: May 2009 Location: Pinehurst, Idaho Posts: 311	Re: Turbo 350 won't shift out of 1st The vacuum lines run to the back of the transmission right above the pan. Passenger side. Well Im gonna check out the governor gear on mine because Im not ready to give up on this transmission yet.

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08-11-2009, 08:26 AM	#3
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,287	Re: Turbo 350 won't shift out of 1st as long as the modulator and the line is good, ive had them blow where you lose everything but first so it may be time for a trans __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!



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