TH350 will not shift up from 2nd
Thread Starter
Heel & Toe
Joined: Aug 2013
Posts: 19
Likes: 0
TH350 will not shift up from 2nd
Tranny has been great but today it will not shift out of 2nd gear.
First to second is fine.
I have checked all vacuum lines, replaced one questionable one and all others look good.
I did damage the EGR control valve since the last drive when I was cleaning the engine bay, but I have blocked off all the vacuum lines to it and still have 18" vacuum at the modulator valve.
Shifter has never lined up perfectly with the letters. When in 3rd, shifter is just below the third marker in the shift plate ( in the cockpit)
I have browsed the forum but don't see anything that I have not already tried.
Any comments would be great.
First to second is fine.
I have checked all vacuum lines, replaced one questionable one and all others look good.
I did damage the EGR control valve since the last drive when I was cleaning the engine bay, but I have blocked off all the vacuum lines to it and still have 18" vacuum at the modulator valve.
Shifter has never lined up perfectly with the letters. When in 3rd, shifter is just below the third marker in the shift plate ( in the cockpit)
I have browsed the forum but don't see anything that I have not already tried.
Any comments would be great.
Thread Starter
Heel & Toe
Joined: Aug 2013
Posts: 19
Likes: 0
No I have not adjusted anything with respect to linkages. I'm afraid I do not know too much about it. Any guidance would be great.
One of my co-workers suggested changing the modulator.. does that make any sense?
One of my co-workers suggested changing the modulator.. does that make any sense?
Thread Starter
Heel & Toe
Joined: Aug 2013
Posts: 19
Likes: 0
When I checked vacuum, I did so at the manifold.
I will have to get down and check the actual modulator, and for 18 bucks, will just change it regardless.
Is 18 " vacuum at idle about right!??
Instructor
Joined: Jun 2013
Posts: 222
Likes: 0
From: Toronto Ontario
This happened to me when I first got our 1980. After being driven for a while after being neglected, all the rubber vac hoses have started breaking down and the smaller damper piece from the steel line to the modulator had a crack in it. It would have broken eventually, but it was just a crack... and it wouldn't shift.
When it first started having trouble it would only shift at 4000+. When that stopped working I would manually shift it and it worked okay. Basically, to get home again, I would ride it hard up to 4000+ with selector in 2, then I would shift down to 1 and back to 2. The interruption from shifting blocked the vac line I guess but it allowed the vacuum to build high enough to shift even with the slight vac leak. I replaced the 2" piece of hose right at th modulator and haven't had any trouble since.
It is in a very difficult location to reach, lying on my back I had to do the work with 1 hand slid in up to the elbow. Not difficult, just do it while the car is cool!
edit: read back to the OP and see you've checked the vac lines already... good luck!
When it first started having trouble it would only shift at 4000+. When that stopped working I would manually shift it and it worked okay. Basically, to get home again, I would ride it hard up to 4000+ with selector in 2, then I would shift down to 1 and back to 2. The interruption from shifting blocked the vac line I guess but it allowed the vacuum to build high enough to shift even with the slight vac leak. I replaced the 2" piece of hose right at th modulator and haven't had any trouble since.
It is in a very difficult location to reach, lying on my back I had to do the work with 1 hand slid in up to the elbow. Not difficult, just do it while the car is cool!
edit: read back to the OP and see you've checked the vac lines already... good luck!
Last edited by brainsoft; Nov 23, 2013 at 06:36 AM.
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Thread Starter
Heel & Toe
Joined: Aug 2013
Posts: 19
Likes: 0
Changed modulator this morning with no improvement. I did notice today that there is no engine braking while I 2nd and decelerating. I am worries this means the issue is internal to the trans.