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Topic: 81 TURBO 350 trans leak

in Forum: C3 Driveline Components


81 TURBO 350 trans leak

Posted: 5/1/07 7:33pm Message 1 of 9
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Hamilton, OH - USA
Joined: 7/5/2006
Posts: 35
Vette(s): 1981 Red Glass Top

Hello hope you guys can help,

I have taken my car in and had the trans filter and fluid changed thinking it was leaking form pan or speedo but it wasn't it turns out it is from the pump and the shifter cable boot.  I don't know who to trust locally to get it resealed without them telling me more once it is apart.  The car has 83,000 miles on it and shifts fine.  What would you reccomend I have done.  Shift kit too? Where how?  I just don't want to jack her up and climb under and pull it out did that once on a car with more space and hated it.>>>>Cincinnati, Ohio
rescuejt2007-05-01 19:33:51


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81 TURBO 350 trans leak

Posted: 5/1/07 7:45pm Message 2 of 9
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20219
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
With 83,000 miles on it, you might as well go ahead and do a rebuild while it's out for the seal job. Wouldn't be much fun to have to do it again in a month or two...
The shifter cable boot can't leak, so I have to assume that's just a typo. The shift lever shaft, that comes out of the driver's side of the trans can leak, tho. It will blow fluid back onto the cable, making the cable wet.
Now, there is a detent/passing gear cable on the pass. side, and it uses a "boot" to seal it to the trans. This can leak, too.
If you want, P/M me with an area code for your location, and I can help locate a shop for you.


Joel Adams
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81 TURBO 350 trans leak

Posted: 5/2/07 9:19am Message 3 of 9
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Victor, NY - USA
Joined: 7/12/2004
Posts: 6842
Vette(s): 2004 Commemorative Edition Coupe, Auto w/HUD. 13K miles in 2015. Sold 1982 Red Coupe
Mine had several leaks: shifter, passing gear and speedo.
Seals replaced at relatively low cost.
Still have one small drip, probably from the pan.



 
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81 TURBO 350 trans leak

Posted: 6/1/07 7:21pm Message 4 of 9
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Hamilton, OH - USA
Joined: 7/5/2006
Posts: 35
Vette(s): 1981 Red Glass Top
Update -She is in the shop!
I turned the Ebay special into my local reccommended trans guy.  Turns out someone prior, disconnected and tied up the lock-up connection for the trans.  It is going to be rebuilt with a shift kit etc being added with a new lock-up converter.  Are there any known problems with the 81's and the lock-up converters?
rescuejt2007-06-01 19:22:26


81 TURBO 350 trans leak

Posted: 6/1/07 7:27pm Message 5 of 9
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20219
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Nope...I would get them to install a higher mph/psi lock-up switch in the valve body, tho. Most of them come stock with a 33psi switch, which equates to about a 33 mph lock-up. This is a little too early, and it can "bog" the engine a bit. The switches are available in many psi ratings. I like to use at least a 45, but 55 is better. That way, the lu doesn't come on until you reach 55 mph.


Joel Adams
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81 TURBO 350 trans leak

Posted: 6/1/07 7:36pm Message 6 of 9
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Hamilton, OH - USA
Joined: 7/5/2006
Posts: 35
Vette(s): 1981 Red Glass Top
Thanks!  I will call them in the morning they tore it down today so I don't think they are there yet.  So it hasn't worked since i had the car so I won't even know what to expect.  The trans was pretty worn according to the trans guy he felt they disconnected it because the converter was going.


81 TURBO 350 trans leak

Posted: 6/1/07 7:44pm Message 7 of 9
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20219
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
That's probably a good assessment. Most folks did disconnect them...too "busy"...going in & out of LU all the time. That's why I suggested a higher psi switch. That keeps it(Lock-up) off until you're cruizing at highway speeds.

You can "expect" to feel what amounts to another "shift" after 3rd gear. It won't be a solid a feel as a shift, but you should still be able to feel it. It will also help with the fuel mileage, but only on longer trips. Maybe 1-2mpg, depending on how long yer legs are!


Joel Adams
C3VR Lifetime Member #56    

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             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

81 TURBO 350 trans leak

Posted: 6/5/07 7:48am Message 8 of 9
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Hamilton, OH - USA
Joined: 7/5/2006
Posts: 35
Vette(s): 1981 Red Glass Top

The transmission repair shop is still having hard time with the lock-up and is trying to find a diagnostic port to view and test did these have one?  My Car is a St. Louis Car and they cannot find it where they thought it would be. Any ideas on how to troubleshoot this one?




81 TURBO 350 trans leak

Posted: 6/5/07 9:59am Message 9 of 9
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20219
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Run, Forest, RUN!!!!
If those guys don't know how to trouble-shoot a 350C(lock-up) trans, you might be in trouble!
The lock-up is controlled by the vehicle speed/governor pressure more than anything else. All the trans needs is 12v on the connector to work, normally in the "B" terminal of the connector, but it should be a Purple wire. It should be "hot" any time the key is on, and the brake pedal is NOT pressed.
Have them check for 12v on that wire. If there is 12v there, and you have no LU, then the pressure switch is bad, the LU valve(in valve body) is stuck, or the LU solenoid is bad.
It's a waste of time to look for a ADLC, as it will give no info other than codes...no data. If the "Check Eng" lite is not on, there will be no codes, anyway.

Your car does have the ADLC connector, and it should be under the dash, driver side, to the left of the headlight over-ride switch.(actually, it's under the ashtray...)Like I say, tho, it won't be much help.
They need to look at a wiring diagram to solve this one. It's a fairly simple set-up.Adams' Apple2007-06-06 05:21:54


Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

in Forum: C3 Driveline Components


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