C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

TH700R4 help

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Old 07-03-2017, 05:31 PM
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Jdog91
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Default TH700R4 help

After converting my 1984 chevy corvette to a carb the transmission now engages for a second but the feel it slipping. Haven't installed the lockup kit yet but is it required? Looked around for a plug there wasn't anything? Could the computer be the cause? I have no idea. And yes I have fluid in there.
Old 07-03-2017, 05:43 PM
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confab
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1) Did you reconnect the TV cable properly? It's important. It can burn your trans if not attached and adjusted properly.

2) Lockup really should be enabled at some point. It lets the transmission run cooler and you use less fuel.
Old 07-03-2017, 05:47 PM
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Jdog91
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No I did not the tv cable measured its sort of attached to the carb. It works for a minute but then slips. Is it still good?
Old 07-03-2017, 05:47 PM
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Jdog91
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How do I disconnect the harness on the side of trans
Old 07-03-2017, 05:52 PM
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confab
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Originally Posted by Jdog91
No I did not the tv cable measured its sort of attached to the carb. It works for a minute but then slips. Is it still good?
I dunno what you mean by "slip" You mean the adjustment slips? It's got a little ratchet thing in there. If it slips, it may be bad or it may be self adjusting.

It's kind of a big deal because it affects line pressure rise, and line pressure is the pressure that keeps your transmission from burning up.

It needs to be the proper distance from the center of the rod that runs the butterflys so you have the right curve in your rise. (Measure it on your old setup.) If it is not, you can get good numbers with a pressure gauge but still burn it up because the rate of rise is incorrect.

As a general rule it should be at max tension at WOT.

The connector on the trans just clips on..

Last edited by confab; 07-03-2017 at 05:55 PM. Reason: I cAnT SpEEL!!
Old 07-03-2017, 05:56 PM
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Jdog91
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It drives but then a quarter mile later loses power like someone is slowly putting on a clutch if it were a manual. It's at max tension at wide open throttle
Old 07-03-2017, 05:56 PM
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confab
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PS: Work out the line pressure/TV cable issue first.. You can worry about lockup later.

If you mess the TV issue up, lockup won't matter because you won't have a transmission left.
Old 07-03-2017, 05:58 PM
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confab
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Originally Posted by Jdog91
It drives but then a quarter mile later loses power like someone is slowly putting on a clutch if it were a manual. It's at max tension at wide open throttle
Well, provided the distance from the TV cable attachment point to the center of the butterfly rod on your carb is the same as your old setup? That should be fine.

Sure it's not an engine performance issue?
Old 07-03-2017, 05:59 PM
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Jdog91
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So my transmission is done is there any way I can check
Old 07-03-2017, 06:01 PM
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Jdog91
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Engine idles very good after much expense
Old 07-03-2017, 06:02 PM
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confab
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Originally Posted by Jdog91
So my transmission is done is there any way I can check
I dunno if it is bad yet. It will be if you drive it around with the TV screwed up.

I dunno what you mean by this binding thing. That's not how 700's typically fail. Typically, in a case like yours, they'll shift to third and flare. THEN, it is bad.

Could it be an engine performance issue? I mean, you just got it together with the carb, right?
Old 07-03-2017, 06:04 PM
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Jdog91
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it has no trouble picking up speed at all
Old 07-03-2017, 06:04 PM
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Jdog91
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For about a quarter mile
Old 07-03-2017, 06:05 PM
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Jdog91
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Does this transmission have a clutch inside of it in any way I can switch on and off
Old 07-03-2017, 06:07 PM
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confab
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The TCC clutch switches on and off.. But it probably isn't working if you gutted the wiring to install the carb.

You can pull the trans connector to be sure it's not some fault in the cut wiring... It can't come on then.
Old 07-03-2017, 06:10 PM
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Jdog91
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Doesn't the transmission need power to it?
Where is this located I was under there and had to reach to anything.
Old 07-03-2017, 06:12 PM
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confab
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Originally Posted by Jdog91
Doesn't the transmission need power to it?
Where is this located I was under there and had to reach to anything.
Not now, no. It only needs power to run the lockup clutch.

The connector is on the driver's side. Look above the linkage.

Lockup should be fixed at some point, but it isn't important right now.

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Old 07-03-2017, 09:04 PM
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arbee
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In addition to what Confab has posted, if you have converted to carb, it is essential you have the correct TV linkage installed on your carb to maintain the proper geometry. They are available for your model from places like Summit.
Old 07-04-2017, 03:07 AM
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Cliff Harris
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This picture shows the TCC and OD wiring connector. The OD wiring is used by the cruise control.



This link tells a lot about the TV system:

http://www.tvmadeez.com/article/index.php
Old 07-04-2017, 09:36 AM
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Jdog91
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If I could post a video I would . All gears are lost when warmed up almost like it's in neutral. Very strange. Could old fluid be the cause. Should I flush the liquid I know it's a pita to drop the pan.


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