drive or overdrive
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Joined: Jun 2002
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From: Oakville CT
Rebuilt Performance Transmission
i just had my automatic transmission (1985 700r4)rebuilt as a street / strip tranny by Gran Trans in West Haven :hurray: - cost me $1,600.I have never had a high performance tranny before. There is a significant difference between drive and overdrive as far as the shifts are concerned - it shifts really hard in drive, especially between 1st and second and also on the down shift between 1st and 2nd. They told me there is no real reason to use drive and i should keep it in overdrive. So far i think that i do get better performance and harder shifts out of drive rather than overdrive. For normal street driving i do prefer overdrive, but if i were to race i think i would leave it in drive.
Is there any real performance gain in drive? what is drive primarily used for? can i cause any damage by using drive in normal driving condition? Is there really a break in period for rebuilt performance transmissions? is there any other concerns that i should have?
Thanks
Paul
[Modified by luck38, 4:01 PM 4/29/2004]
Is there any real performance gain in drive? what is drive primarily used for? can i cause any damage by using drive in normal driving condition? Is there really a break in period for rebuilt performance transmissions? is there any other concerns that i should have?
Thanks
Paul
[Modified by luck38, 4:01 PM 4/29/2004]
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From: Connectivette
Re: Rebuilt Performance Transmission (luck38)
I'm a Gran Trans member also. I don't remember Grant or Mike telling me that when they re-built my 700R4. I leave mine in "D" in the city and "OD" on the highways. From what I've heard it is not the best thing for your tranny to keep going in and out of "OD" during city driving.
I also like the sound at higher RPM's :thumbs:
I also like the sound at higher RPM's :thumbs:
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: Rebuilt Performance Transmission (luck38)
I agree with the last two posts. Beside comfort, I think it is better for the trans, also. My last performace (race?) rebuild has a brutal 2-1 downshift when I come to a stop. Even if I downshidt to 3rd while slowing down for a freeway ramp, I have to shift back to OD before the trans wants to go into first , just to save my teeth. I think the trans is stout as hell. They told me it's good for 700+ hp, but as good as the hardware may be, I don't think they are valvebody or programming genius's.
RACE ON!!!
RACE ON!!!
Le Mans Master
Joined: May 1999
Posts: 6,517
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From: Windermere FL
Re: Rebuilt Performance Transmission (luck38)
Funny, I just noticed that the one Mad Dog built for me does the same. In D the shifts and especially the down shifts are very hard. OD is crisp, and the down shifts are not hard at all.
When I shift from R to D or Park into any gear it feel like it is going to rip my U-joints apart :lolg:
When I shift from R to D or Park into any gear it feel like it is going to rip my U-joints apart :lolg:
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Joined: Oct 2001
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From: Connectivette
Re: Rebuilt Performance Transmission (luck38)
Chuck, do you also have a great difference in shifting between OD and D? Does your 1-2 and 2-1 shift in D really hit hard?
Burning Brakes
Joined: Dec 2002
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From: Lakeland fl
Re: Rebuilt Performance Transmission (luck38)
There is no break in period for an automatic transmission. The only thing in there are clutch plates/steels, and some lip seals and bushings. None of which require a break in. Problems with gear selection are not attributable to a "break in", but are more likely a blocked passage (that may become unblocked), poor clutch clearances, or an internal leak. The last two will change their "feel" with changes in tranny temperature.
I leave my OD in OD most of the time, but I would recommend D for most in town driving due to most Vettes already numerically low (high) axle ratio. Pushing that kind of ratio puts alot of stress on the trans when going slower than 50 or so.
I leave my OD in OD most of the time, but I would recommend D for most in town driving due to most Vettes already numerically low (high) axle ratio. Pushing that kind of ratio puts alot of stress on the trans when going slower than 50 or so.
Team Owner
Joined: Apr 2000
Posts: 27,818
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From: CT
Rebuilt Performance Transmission
Heh, this ought to be a GT thread.
I had them re-do mine when the rossler build failed at 5000 miles. Grant and Mike are stand up guys and do a nice job.
Mine shifts firmly 1-2 2-3 at lower speeds such as traffic etc. The downshift is firm as well.
I have 3.45 gears in my D44 and I keep mine in "D" around town(under 65 mph) on the highway, obviously O/D.
MrNuke just had a 700 done by Grant and Mike. I couldn't believe the difference from his old "slushy slippy" 700 to the one they did for him.
203.933.0053 to those who'd like one done by them. :cheers:
I had them re-do mine when the rossler build failed at 5000 miles. Grant and Mike are stand up guys and do a nice job.
Mine shifts firmly 1-2 2-3 at lower speeds such as traffic etc. The downshift is firm as well.
I have 3.45 gears in my D44 and I keep mine in "D" around town(under 65 mph) on the highway, obviously O/D.
MrNuke just had a 700 done by Grant and Mike. I couldn't believe the difference from his old "slushy slippy" 700 to the one they did for him.
203.933.0053 to those who'd like one done by them. :cheers:
Melting Slicks
Joined: Sep 2003
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From: 1,000,000,001 Posts
Re: Rebuilt Performance Transmission (Jay 383)
This is very good info to know,...
I had my 700R4 built last year,,, and I have been wondering, why, the downshifts have been so harsh.... Sometimes it does feel like it is going to rip the u-joints right out of the car,,,, mabey this is why I have to retighten my c-bar every 2 months.... :confused:
I had my 700R4 built last year,,, and I have been wondering, why, the downshifts have been so harsh.... Sometimes it does feel like it is going to rip the u-joints right out of the car,,,, mabey this is why I have to retighten my c-bar every 2 months.... :confused:
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Joined: Jun 2002
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From: Oakville CT
Re: Rebuilt Performance Transmission (Jay 383)
Jay - thanks for the input - im really a newbie as far as performance parts go (got my income check back :hurray: ) so i decided to fix the leak in the front seal of the transmission - turned out i spent the money for the street / strip setup without the torque converter (next years income tax = 383 stroker or if i save enough a 400 block setup, so I said - might as well have the transmission that can handle the power). I just wanted confirmation that what i was experienced was normal for this setup. Thanks to all those who gave me feedback.
Paul
Paul
Team Owner
Joined: Apr 2000
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From: CT
Rebuilt Performance Transmission
Paul
What color is the car? was it the same car there that was next to Gabe's silver '85?
:cheers:
[EDIT] Paul, also there'll be a corvette only show at Heavenly Doughnuts in Derby. That should be getting underway soon. Chuck, Gabe, and quite a few other forum members show up. Sundays are cool too as everything shows up there from old 'vettes to ferrari's to classic muscle cars.
[Modified by Jay 383, 11:23 AM 4/30/2004]
What color is the car? was it the same car there that was next to Gabe's silver '85?
:cheers:
[EDIT] Paul, also there'll be a corvette only show at Heavenly Doughnuts in Derby. That should be getting underway soon. Chuck, Gabe, and quite a few other forum members show up. Sundays are cool too as everything shows up there from old 'vettes to ferrari's to classic muscle cars.
[Modified by Jay 383, 11:23 AM 4/30/2004]
Melting Slicks
Joined: Nov 2003
Posts: 3,375
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From: Northern CA
Re: Rebuilt Performance Transmission (luck38)
Driving an automatic is too complicated for simple folk like me, that's why I have a 6 speed.
But here's the secret to driving an automatic.
For a fast start, start out in "L"unge
Then once you get moving good, shift it to "D"rag.
That should do the trick, but if your comptition is still gaining on you, shift it to "R"ace, but hang on because that's a real firm shift.
If he still pulls ahead of you after you shift to "R"ace, use you ace-in-the-hole. Shift into "Pass" to catch up with him.
[Modified by xs650, 8:45 AM 4/30/2004]
But here's the secret to driving an automatic.
For a fast start, start out in "L"unge
Then once you get moving good, shift it to "D"rag.
That should do the trick, but if your comptition is still gaining on you, shift it to "R"ace, but hang on because that's a real firm shift.
If he still pulls ahead of you after you shift to "R"ace, use you ace-in-the-hole. Shift into "Pass" to catch up with him.
[Modified by xs650, 8:45 AM 4/30/2004]
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Joined: Jun 2002
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From: Oakville CT
Re: Rebuilt Performance Transmission (Jay 383)
Jay
Also a silver 85 but with the torn out interior and only the drivers seat in it - im redoing the interior (or i was, transmission just set that back a couple of months)
Paul
[Modified by luck38, 4:52 PM 4/30/2004]
[Modified by luck38, 5:10 PM 4/30/2004]
Also a silver 85 but with the torn out interior and only the drivers seat in it - im redoing the interior (or i was, transmission just set that back a couple of months)
Paul
[Modified by luck38, 4:52 PM 4/30/2004]
[Modified by luck38, 5:10 PM 4/30/2004]
Drifting
Joined: Jan 2002
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From: I Hate Tourists FL
Re: Rebuilt Performance Transmission (Flame Red)
Funny, I just noticed that the one Mad Dog built for me does the same. In D the shifts and especially the down shifts are very hard. OD is crisp, and the down shifts are not hard at all.
When I shift from R to D or Park into any gear it feel like it is going to rip my U-joints apart :lolg:
When I shift from R to D or Park into any gear it feel like it is going to rip my U-joints apart :lolg:
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Re: Rebuilt Performance Transmission
Hey there, i see we are neighbours. I jsut moved to waterbury, by the watertown line.
ANyhow, I just got my tranny rebuilt by Grant, and drive and oevrdrive both catch 2nd gear, but in Overdrive it upshifts to 3rd a bit earlier than in 'D'.
I keep it in D for in-town and racing, and Overdrive for above 50mph speeds.
The only thing I noticed is that my oil temperature now is about 10-15F higher at warmer days at highway speeds. I think teh hgher stall converter (2400rpm) might be running the tranny fluid hotter than before, and since I have a tranny cooler, it increases the temp of the oil in teh oilcooler it is next to.
By the way, my car doesn't upshift at WOT to 4th anymore.
But... At least I won't be doing a lot of high speed racing.
3rd gets me to 117MPH at 5500rpms just fine..
:jester
ANyhow, I just got my tranny rebuilt by Grant, and drive and oevrdrive both catch 2nd gear, but in Overdrive it upshifts to 3rd a bit earlier than in 'D'.
I keep it in D for in-town and racing, and Overdrive for above 50mph speeds.
The only thing I noticed is that my oil temperature now is about 10-15F higher at warmer days at highway speeds. I think teh hgher stall converter (2400rpm) might be running the tranny fluid hotter than before, and since I have a tranny cooler, it increases the temp of the oil in teh oilcooler it is next to.
By the way, my car doesn't upshift at WOT to 4th anymore.
But... At least I won't be doing a lot of high speed racing.
3rd gets me to 117MPH at 5500rpms just fine..
:jester