No overdrive

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Feb 24, 2007 | 07:37 PM

dglad

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From: Beloit Wisconsin

No overdrive

Hello all im looking at buying a 91 vette the only problem is it wont go into overdrive all 3 gears work just not overdrive could this be something simple like changing the trans fluid the car has been sitting for a while.

Feb 24, 2007 | 08:07 PM

Deakins

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Joined: Sep 2005

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From: Iowa

What do you mean when you say it won't go into overdrive? Does it free wheel or does it just stay in third? How does it shift? Does it shift at normall RPM? These will tell us if it is a simple problem or a more complex one.

Feb 24, 2007 | 08:25 PM

dglad

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From: Beloit Wisconsin

it shifts fine in the first three gears but it wont go to overdrive it just stays in third and the faster you go the higher the rpms go

Feb 24, 2007 | 10:07 PM

Pete K

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If you are lucky, it is misadjusted shifter linkage. If not, it is likely in the valve body. 3rd gear and 4th gear share the same clutch pack. The servo applys the band for 2nd and 4th . The fact that you have 2 and 4 suggests the band and reaction shell is fine.

Feb 25, 2007 | 12:24 AM

VetteTech81

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Joined: Nov 2002

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From: Charlotte, NC

you may need the trans rebuilt... you can always try flushing it... but it probably won't help... I agree it could be linkage or valveing issue.. or possibly the torq converter is not locking up?
-=Rick

Feb 25, 2007 | 10:47 AM

dglad

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From: Beloit Wisconsin

if i need to have it rebuilt is it better to rebuild the one in it or is it the same trans as whats in like an iroc or gta

Feb 25, 2007 | 12:46 PM

Pete K

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Quote:

Originally Posted by dglad

if i need to have it rebuilt is it better to rebuild the one in it or is it the same trans as whats in like an iroc or gta

Yes and no. There are dozens of differences between the iroc and vette transmission. You can mod the f-body trans to work, but it will not have the same "character" as the vette trans.
In my opinion, rebuilding yours is wise.

Feb 25, 2007 | 01:24 PM

Aardwolf

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Joined: Jun 2004

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From: WI

Mine had trouble getting fourth last year. I changed the fluid, added Sea Foam trans. fluid and drove the car about fourty miles, the gear came back. I had a shift kit waiting on the bench to install so I popped the pan, it didn't look to bad in there. Dropped the valve body, found hard clear plastic looking debris (varnish?), almost like popcorn husks. There was not many of them, I figured that was what the problem was. I also changed the TV cable, it would not adjust correctly. The new one works great.