76 auto, stuck in second gear...
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
76 auto, stuck in second gear...
Took the vette for a little longer cruise yesterday, about 30 miles...air temp about 53*, we had lunch at the lake and headed back home....exiting a counrty road inersection, (radio was up), I glanced down and noticed the tach riding at about 3800 rpm, dropped the audio and listened...the tranny wouldn't shift up to third, let off on throttle and it shifted up, after a bit...did it again shortly after. Got home and checked fluid, was at the correct hot mark and looks clean.
This morning took it out again, engine still cool, stuck again, home and discovered tranny vacuum was loose, just pushed on, I put a clamp on the hose which is on the manifold vac side of the primary quad and went back out. Seemed to shift normal, but from about 30 mph into passing gear, it kicked up to 3rd at 4700 rpm (a little close to that red line for me).
So, before I loose more sleep, can anybody verify that a vac leak might cause this...is 4700 rpm normal to shift to 3rd on passing speed....might this be a warning of a cash cow walking my way????
HELP!!
This morning took it out again, engine still cool, stuck again, home and discovered tranny vacuum was loose, just pushed on, I put a clamp on the hose which is on the manifold vac side of the primary quad and went back out. Seemed to shift normal, but from about 30 mph into passing gear, it kicked up to 3rd at 4700 rpm (a little close to that red line for me).
So, before I loose more sleep, can anybody verify that a vac leak might cause this...is 4700 rpm normal to shift to 3rd on passing speed....might this be a warning of a cash cow walking my way????
HELP!!
Intermediate
Joined: May 2005
Posts: 42
Likes: 0
I had a problem shifting into 3rd on mine and it was the linkage that is attached to the carb throttle. There is a procedure to "reset" the position of the linkage but I can't remember how to do it. I tried to look under my hood to jog my memory but my vette is under a mountain of stuff brought inside for hurricane Wilma. I am sure someone else fill in the details.
Intermediate
Joined: May 2005
Posts: 42
Likes: 0
Since no one else filled in the details, I found a website that describes the procedure to reset the transmission kickdown cable. This cable determines when to downshift and how much throttle keeps the transmission in second gear.
"To adjust (the cable stretches over time, I do this every 6 months or so), press the button on the cable adjuster at the bracket in (can be hard to press), and push cable in from the away from the carb. Then (engine off please) move the throttle to full throttle. Failure to do this last step can damage the transmission!! DO NOT drive a THM 200 4R or THM 200C with the TV cable out of adjust, this can kill one of these transmissions. It will click till it self adjusts to the correct setting. That is all. Very easy proceedure."
It takes less than a minute. Hope this fixes your problem.
Here is the link to the page, http://bnol.com/troberts/oldsfaq/oftrn.htm .
"To adjust (the cable stretches over time, I do this every 6 months or so), press the button on the cable adjuster at the bracket in (can be hard to press), and push cable in from the away from the carb. Then (engine off please) move the throttle to full throttle. Failure to do this last step can damage the transmission!! DO NOT drive a THM 200 4R or THM 200C with the TV cable out of adjust, this can kill one of these transmissions. It will click till it self adjusts to the correct setting. That is all. Very easy proceedure."
It takes less than a minute. Hope this fixes your problem.
Here is the link to the page, http://bnol.com/troberts/oldsfaq/oftrn.htm .
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Originally Posted by second76
Since no one else filled in the details, I found a website that describes the procedure to reset the transmission kickdown cable. This cable determines when to downshift and how much throttle keeps the transmission in second gear.
"To adjust (the cable stretches over time, I do this every 6 months or so), press the button on the cable adjuster at the bracket in (can be hard to press), and push cable in from the away from the carb. Then (engine off please) move the throttle to full throttle. Failure to do this last step can damage the transmission!! DO NOT drive a THM 200 4R or THM 200C with the TV cable out of adjust, this can kill one of these transmissions. It will click till it self adjusts to the correct setting. That is all. Very easy proceedure."
It takes less than a minute. Hope this fixes your problem.
Here is the link to the page, http://bnol.com/troberts/oldsfaq/oftrn.htm .
"To adjust (the cable stretches over time, I do this every 6 months or so), press the button on the cable adjuster at the bracket in (can be hard to press), and push cable in from the away from the carb. Then (engine off please) move the throttle to full throttle. Failure to do this last step can damage the transmission!! DO NOT drive a THM 200 4R or THM 200C with the TV cable out of adjust, this can kill one of these transmissions. It will click till it self adjusts to the correct setting. That is all. Very easy proceedure."
It takes less than a minute. Hope this fixes your problem.
Here is the link to the page, http://bnol.com/troberts/oldsfaq/oftrn.htm .
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Thanks second76 for that info...hopefully that is all I need to do and the problem will go away...I could see tranny work on the horizon, this is much better news...
