Click on image for the lowdown. 
====
| | | Forums66 Topics128,026 Posts1,055,404 Members48,422 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Sep 2007 Posts: 31 Apprentice | | Apprentice Joined: Sep 2007 Posts: 31 | I have a 350 automatic in my '49, behind a 250 6 cyl. Have been running this for about 2 years, no trouble, about 5,000 miles.
The other day, drove about 30 miles on highway, got into a small town and slowed down, then the tranny started missing while trying to get back up to speed. Basically would not go into "high gear". Engine RPMs went high, as if a clutch was pushed in (remember this is a 350 AUTO). I slowed to about 35-40, it slid into high gear and was "fine" after that.
Last couple days it has been doing it again, but now slipping out of gear at speed, around 50-55. RPMs shoot way up, I pull over or slow down, gets better.
Fluid is at the right level, not burnt at all. I checked the vacuum line, does not appear cracked but I am going to replace anyway.
I have hear of a small part on the tranny that can go bad (forget name), near the rear of the tranny. Or the whole thing may just be toast.
Any ideas?
Thanks in advance.
1949 5 Window 3100
| | | | | Joined: Dec 2001 Posts: 14,522 Moderator: Welcome Centre, Southern Bolters, Legion Hall | | Moderator: Welcome Centre, Southern Bolters, Legion Hall Joined: Dec 2001 Posts: 14,522 | .... would you be talking about the modulator? | | | | | Joined: Feb 2000 Posts: 5,195 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,195 | Could be the modulator, does it free wheel or is it stuck in second gear?
| | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy Meyer, 350s have a "nylon" governor drive gear, which tends to fail, with no governor pressure the tranny will not shift up. the governor is at the rear of the transmission, under a stamped steel cover retained by a wire clamp I can't remember which side it is on. If you pry the clip off and take the cover off you should be able to pull the governor out of the transmission, the damage to the gear will be obvious. You can replace the governor with a rebuilt one, but the way I understand this problem, a bushing in the rear of the transmission housing or tailshaft housing has worn, allowing the output shaft to put pressure on the governor drive gear, wearing it out, so mearly replacing the damaged part will only give you a short lived repair, hope that helps. | | |
|
|
