Torque converter lock up

B

buchshot1

Registered
Well my t/c is still locking up early, I put a new tcc soliniod in it. still locks up as soon as goes in second. and it only seems to unlock when I manually put into first.

After I drive it for a little it behaves better, or its just slipping. It wont unlock when I hit the brakes. Is there a way to test the computer to make sure its working correctly.
thanks for any help.
 
Excerpts from the manual...

The following items must be checked before proceeding:

-- Check the PCM for proper function (On Board Diagnostics).

-- Check vehicle wiring harness for continuity and shorts to ground.

-- Make sure all connectors are engaged properly.

-- Make sure all terminals in connectors are properly seated.

-- Check all connectors for damage, corrosion, water, bent pins and missing or damaged seals.
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l Check that vehicle harness connector and terminals are fully engaged on transmission connector.

l Check that vehicle harness connector terminals are fully engaged in connector.
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l Disconnect vehicle harness at transmission.

CAUTION:
Do not pry connector. Press the tab and pull on vehicle harness connector.

l Install Rotunda Transmission Tester (007-00085) or equivalent to transmission connector.

l Using tests outlined under Tester Instructions, perform TCC solenoid function test.

NOTE:
LED will turn GREEN when solenoid activates and turn OFF when deactivated. LED will turn RED if an ACTIVATED solenoid/harness is shorted to battery positive. LED will remain off if an ACTIVATED solenoid/harness is shorted to ground or no continuity (open circuit).
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l Perform Transmission Drive Test as outlined under testing instructions.

l While in second gear press the MCCC switch.

l Does the TCC activate (LED GREEN)?

l Does the engine rpm drop?
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buchshot1 said:
Well my t/c is still locking up early, I put a new tcc soliniod in it. still locks up as soon as goes in second. and it only seems to unlock when I manually put into first.

After I drive it for a little it behaves better, or its just slipping. It wont unlock when I hit the brakes. Is there a way to test the computer to make sure its working correctly.
thanks for any help.
Click to expand...

Is it the stock TC?

My Art Carr converter did that when it died. A very low quality product.
 
J said:
Depends....what year of vehicle do you have? :D
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its a 94

I found a guy with a snap on scanner and we hooked it up. there were no codes.

I also talked with a tranny builder, He thinks there is a issue in the valve body or the 1-2 accumulator. I've seen the fluid flow diagrams some where, but I cant remember where. does anyone know where I can find them.
 
buchshot1 said:
Well my t/c is still locking up early, I put a new tcc soliniod in it. still locks up as soon as goes in second. and it only seems to unlock when I manually put into first.

After I drive it for a little it behaves better, or its just slipping. It wont unlock when I hit the brakes. Is there a way to test the computer to make sure its working correctly.
thanks for any help.
Click to expand...

Re-reading your original post, I believe your TCC solenoid is either not working or you have a wiring fault that is not allowing the signal to reach the solenoid.

Check the transmission wiring, especially the bulkhead connector and harness connector to the main car wiring.
 
buchshot1 said:
I new I saw them some where. I have an account with alldata.
from what I've found. It might be a valve body problem I just need to find a good on to test out that thoery.
Click to expand...

If I remember, the TCC solenoid controls the hydraulic shifting of a valve in the valve body which is what redirects a regulated flow to the converter clutch. This flow is the same as the 2-3 shift circuit. The reason I know this is that this is what caused my converter to NOT lockup initially with the new tranny.

In my case, the 2-3 accumulator was bypassing causing a loss of pressure required for the TCC lockup, even though the TCC solenoid was working. I theorize the opposite could happen where the valve in the valve body could be 'stuck' causing pressure to the TCC all the time except when in 1st gear.

If that theory holds water, a new valve body may be the cure, but I would certainly investigate the accumulators as well.

Please keep us informed.
 
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