'91 Automatic OD trouble
Thread Starter
Instructor
Joined: Sep 2012
Posts: 249
Likes: 2
From: Watkins Glen NY
'91 Automatic OD trouble
Trouble today. Headed 1 hour into a 2 hour trip and noticed that my shift light was on. (1991 Automatic)
The car would not go into Overdrive even though the shifter was there. Acting very weird, all fluids good, nothing leaking, ran perfectly up to then.
Drove back home and get another car to complete the trip. Have to research it and figure out WTF. Sucks to have issues on such a perfect day.
BTW thanks to the guy in the white '10 Z06 that came over in the gas station @ the Steam Valley exit (15s) to see if he could help.
Just starting the research on the Forum today.
The car would not go into Overdrive even though the shifter was there. Acting very weird, all fluids good, nothing leaking, ran perfectly up to then.
Drove back home and get another car to complete the trip. Have to research it and figure out WTF. Sucks to have issues on such a perfect day.
BTW thanks to the guy in the white '10 Z06 that came over in the gas station @ the Steam Valley exit (15s) to see if he could help.
Just starting the research on the Forum today.
Thread Starter
Instructor
Joined: Sep 2012
Posts: 249
Likes: 2
From: Watkins Glen NY
Drove over an hour home with car in (OD) 3rd @ 3,000 rpms. Never slipped on the hills, and ran great.
A couple times on the down hills the tach would go down to 1,200 rpms like it went to OD but any throttle made it go back to 3rd @ 3,000rpm.
Is there any vacuum that controls the tranny? I just can't figure out what would make it act up when every thing was fine on a gentle cruise.
A couple times on the down hills the tach would go down to 1,200 rpms like it went to OD but any throttle made it go back to 3rd @ 3,000rpm.
Is there any vacuum that controls the tranny? I just can't figure out what would make it act up when every thing was fine on a gentle cruise.
Le Mans Master
Joined: Feb 2005
Posts: 6,479
Likes: 565
From: Clearwater Florida
..... No vacuum influence , the only external input is through the TV cable ... 4th gear shares the same clutches as 3rd but also applies the band to force power through the planetary gear set for multiplication ... there is a possibility that the shift cable or lever are at fault but that would usually affect other gear selections , particularly Park ... on the plus side the 2nd and 4th servos are accessible without removing the trans ... its on the pass side just behind the dipstick tube .........
Thread Starter
Instructor
Joined: Sep 2012
Posts: 249
Likes: 2
From: Watkins Glen NY
It did act funny when I tried to down shift it. Almost like the shifter was off by a half a click. I wonder if that can come loose?
I left the car at my shop so I can work on it, can't look at it until tomorrow. Got a lot of snooping to do.
Where to start?
I left the car at my shop so I can work on it, can't look at it until tomorrow. Got a lot of snooping to do.
Where to start?
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
There is an adjustment for the shifter cable on the shift lever on the transmission. It's possible that it slipped.
There is a 15mm nut that holds the pin that the shift cable attaches to. It adjusts by sliding in a slot on the shifter lever:
There is a 15mm nut that holds the pin that the shift cable attaches to. It adjusts by sliding in a slot on the shifter lever:
Thread Starter
Instructor
Joined: Sep 2012
Posts: 249
Likes: 2
From: Watkins Glen NY
Finally had time to check out my '91.
I adjusted the TV cable which seemed to end up in the same place it was before. Drove the car and it seemed fine, but after about a 1/6th of a mile I went to turn around and I couldn't get the car to move.
I had some trouble getting it into park. so I reset the TV cable to make sure it was right. The car ran good back down the road but then it acted like it was running out of fluid.
Took it back to the garage, shut it off. 5 minutes later it tried just moving forward and backward in the garage. Worked fine but then seemed to run out of fluid. I have been checking the fluid all along and it was right on. The filter was changed and new fluid 5000 miles ago.
Is there a pump that can go bad? Could it be my converter? I did here a whirling sound when I got it out this spring that I never remembered before.
Anyone ever have the same issues? I'm hoping this will be something simple, if not the car will be taken off the road until I can fix it.
I adjusted the TV cable which seemed to end up in the same place it was before. Drove the car and it seemed fine, but after about a 1/6th of a mile I went to turn around and I couldn't get the car to move.
I had some trouble getting it into park. so I reset the TV cable to make sure it was right. The car ran good back down the road but then it acted like it was running out of fluid.
Took it back to the garage, shut it off. 5 minutes later it tried just moving forward and backward in the garage. Worked fine but then seemed to run out of fluid. I have been checking the fluid all along and it was right on. The filter was changed and new fluid 5000 miles ago.
Is there a pump that can go bad? Could it be my converter? I did here a whirling sound when I got it out this spring that I never remembered before.
Anyone ever have the same issues? I'm hoping this will be something simple, if not the car will be taken off the road until I can fix it.
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
Finally had time to check out my '91.
I adjusted the TV cable which seemed to end up in the same place it was before. Drove the car and it seemed fine, but after about a 1/6th of a mile I went to turn around and I couldn't get the car to move.
I had some trouble getting it into park. so I reset the TV cable to make sure it was right. The car ran good back down the road but then it acted like it was running out of fluid.
Took it back to the garage, shut it off. 5 minutes later it tried just moving forward and backward in the garage. Worked fine but then seemed to run out of fluid. I have been checking the fluid all along and it was right on. The filter was changed and new fluid 5000 miles ago.
Is there a pump that can go bad? Could it be my converter? I did here a whirling sound when I got it out this spring that I never remembered before.
Anyone ever have the same issues? I'm hoping this will be something simple, if not the car will be taken off the road until I can fix it.
I adjusted the TV cable which seemed to end up in the same place it was before. Drove the car and it seemed fine, but after about a 1/6th of a mile I went to turn around and I couldn't get the car to move.
I had some trouble getting it into park. so I reset the TV cable to make sure it was right. The car ran good back down the road but then it acted like it was running out of fluid.
Took it back to the garage, shut it off. 5 minutes later it tried just moving forward and backward in the garage. Worked fine but then seemed to run out of fluid. I have been checking the fluid all along and it was right on. The filter was changed and new fluid 5000 miles ago.
Is there a pump that can go bad? Could it be my converter? I did here a whirling sound when I got it out this spring that I never remembered before.
Anyone ever have the same issues? I'm hoping this will be something simple, if not the car will be taken off the road until I can fix it.
Thread Starter
Instructor
Joined: Sep 2012
Posts: 249
Likes: 2
From: Watkins Glen NY
Some people have told me that I might have a loose filter. Something about double O-rings.
I'm gonna check that first then decide what to do.
How much should a rebuild cost? Not positive I can do it myself (a little chicken)
I'm gonna check that first then decide what to do.
How much should a rebuild cost? Not positive I can do it myself (a little chicken)
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Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You do need at least one O-ring. If that were a problem you'd have major slipping, especially in 3rd gear, because the pump would be sucking air and the pressure would be very low.
Price for a rebuild varies greatly depending on what you want done to the trans (and who does the rebuild). I have had two 700r4 rebuilds. Both of them cost $950 for a mostly stock rebuild. The second trans had a lot of mods in it but the rebuilder just re-used the modified parts that were already there.