no lock converter
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
Lock converter
I found a few posts taking about the wire to manually lock the converter but I am a little dense. Can one of the trans guys shed a little light for a thick headed guy?
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Lockup requires a command from the ECM, or as in earlier days, a 12v source to the TCC solenoid in the tranny. The 350C or in your case the 700R4, gets a signal from the ECM but goes thru a switch or two in the trans to make it lock. If you put 12v to the correct terminal on the side of trans, it'll lockup. You might need to drop the pan to figure out which terminal is which.
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
Lockup requires a command from the ECM, or as in earlier days, a 12v source to the TCC solenoid in the tranny. The 350C or in your case the 700R4, gets a signal from the ECM but goes thru a switch or two in the trans to make it lock. If you put 12v to the correct terminal on the side of trans, it'll lockup. You might need to drop the pan to figure out which terminal is which.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Either one, the basic idea is the same. I think the 350C had a switch that closed in 3rd gear and the 700 had one that closed in 4th. There were (are) so many different configurations of switches, solenoids, and outside of the trans controls it's really tough to guess at which does what.
I thought (maybe incorrectly!) that 81 went to the 700R4, but without looking at it I don't know. I do know a couple of guys that have 81's and they are 700R4's
I thought (maybe incorrectly!) that 81 went to the 700R4, but without looking at it I don't know. I do know a couple of guys that have 81's and they are 700R4's
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
I've got a Muncie with 4:11's and I'm right there too. And that's a 1:1 4th. 26 inch tires.
I don't know- did all 81's come with 700's? Options? Did some maybe swap a 350 or 350C in to your car? The 1:1 sure sounds like it could be like a 3:73 rear.
Here's another thing- Early TCC's had a brake switch- From a stop, you should feel distinct shifts and see a drop in RPM as it picks up each gear. A 350 will have 2 shifts- starts in 1, then 2 then 3. If it's a lockup (that's working) you'll get a softer less distinct shift, and the TCC lockup will also have an RPM drop. Same with a 700- 1,2,3,4 followed by lockup. After the lockup, maintain a steady pressure on the throttle and touch the brake just enough to get brake lights- you should feel a definate "bump" when the convertor unlocks and an slight increase in RPM.
I don't know- did all 81's come with 700's? Options? Did some maybe swap a 350 or 350C in to your car? The 1:1 sure sounds like it could be like a 3:73 rear.
Here's another thing- Early TCC's had a brake switch- From a stop, you should feel distinct shifts and see a drop in RPM as it picks up each gear. A 350 will have 2 shifts- starts in 1, then 2 then 3. If it's a lockup (that's working) you'll get a softer less distinct shift, and the TCC lockup will also have an RPM drop. Same with a 700- 1,2,3,4 followed by lockup. After the lockup, maintain a steady pressure on the throttle and touch the brake just enough to get brake lights- you should feel a definate "bump" when the convertor unlocks and an slight increase in RPM.
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Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
only 3
I only feel the three gears shifting. The RPM never drops. The cruise does not work also. Anyone know if they could be related. If the computer can't read the speed for cruise, maybe that is why the lock-up fails also
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
traced wire finally
took a while but traced the wire down. The trans has 12v running to it and the computer grounds as expected, but the TCC does not work. This means the issue is inside.
Any ideas what and how much trouble (or cash) to fix. Sure would be nice to drop a few RPM on those long trips.
Any ideas what and how much trouble (or cash) to fix. Sure would be nice to drop a few RPM on those long trips.
Race Director
Joined: Mar 2008
Posts: 15,161
Likes: 17
From: coffee
I am in the process of de-CCC'ing my '81. If you are having problems with the lockup, maybe something has gone wonky in the wiring or control module. The part in the link below ought to take the place of the CCC functionality. I plan on getting one myself. Wish I had the funds for a Kiesler 5-spd conversion. Maybe some day.
http://www.summitracing.com/parts/BMM-70244/
http://www.summitracing.com/parts/BMM-70244/
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
wish it was the CCC, I could by-pass it. But there is power to the trans and the CCC provides the ground at the proper time, just nothing. The bug is in the trans itself. Really would love to get the RPM down even a little bit on the longer trips.
any ideas anyone?
any ideas anyone?
I am in the process of de-CCC'ing my '81. If you are having problems with the lockup, maybe something has gone wonky in the wiring or control module. The part in the link below ought to take the place of the CCC functionality. I plan on getting one myself. Wish I had the funds for a Kiesler 5-spd conversion. Maybe some day.
http://www.summitracing.com/parts/BMM-70244/
http://www.summitracing.com/parts/BMM-70244/
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
they are just solenoids inside the transmission not a big deal or even expensive.
this is one in the 700r4 that locks up the TC in 3rd
all accesible from the oil pan
this is one in the 700r4 that locks up the TC in 3rd
all accesible from the oil pan
Last edited by bobs77vet; Nov 8, 2009 at 06:38 PM.
Racer
Joined: Nov 2009
Posts: 289
Likes: 0
From: Franksville Wisconsin
Are you supposed to feel the torque converter lock up? I have a '81 and only feel it shift second and third also.....2500 at 60 mph. Also earlier in this post it was asked if computer controls cruise, it does not it is a separate system.Hope this helps ( my cruise is inop too.)
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
you will feel it but you will see it happen on the tach and hear it .....the tach goes from some fluctuation(not locked up)....drops several hundred rpm and stays steady(in lock up)
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
i think
as I understand: power comes from the fuseblock thru the brake switch to the trans. Ground is provided by a relay controled by the computer. I have verified the 12v is there and then the computer is turning the relay on (I even hooked a temp wire to ground it myself). Something is off inside the trans.
