Vanning.com logo
Boxdin
Site Navigation


Advertisements
Recent Posts
Good day
by lukester - March 28th 2024 12:26 pm
Crazy mods
by MufflerMan Mike - March 28th 2024 9:38 am
Lew Greger
by MufflerMan Mike - March 27th 2024 5:15 pm
1987 G20 Gypsy
by SDMickey - March 25th 2024 9:39 pm
Featured Links


Previous Thread
Next Thread
Print Thread
Rate Thread
tourque converter won't lock
#539364 February 14th 2012 3:42 am
Joined: Jan 2001
Posts: 960
old hand
OP Offline
old hand
Joined: Jan 2001
Posts: 960
My 700r4 tourque converter seems to unlock while driving down the road. this I beleive is an electrical problem with the plug on the side.
Am i right???
Will this hurt it?
New plug or computer problem?

1990 astro.


Read your newspaper Daily
Re: tourque converter won't lock
Pup E. Trucker #539485 February 14th 2012 2:23 pm
Joined: Jan 2010
Posts: 573
addict
Offline
addict
Joined: Jan 2010
Posts: 573
This is the best link I found for diagnosing a 700R4 lock-up converter issue :

http://autorepair.about.com/library/ts/bl306a.htm

There are a huge number of things that could be causing a problem. The most common failure is the TCC solenoid inside the trannie pan. It's a 2 minute job once the pan is off, but check to see if it is getting a signal from the ECU first. You can even jump the system through the ALDL connector and test the solenoid that way.
The GM EFI systems from that era are so stupid that there could be a huge number of things wrong causing your problem and yet no fault will come up. What exactly is happening? Is it not working at all, locking and unlocking repeatedly?? I chased my lock up issues for far longer than I care to admit, and in the end it turned out that my vehicle speed sensor was working, but the signal was weak causing my lock up issues. Yet no check engine light and no other problems. I only found it by accident when I switched to a different unit with a manual output as well for my aftermarket speedometer. All of a sudden my lock-up started working again.


Colin
aka "Fatvanman"
1975 Chevy G20 Shorty "Lunchbox"

"The great ones never die, they just get older, fatter and drive better vans!"

http://www.cardomain.com/ride/3913766/1975-chevrolet-van
Re: tourque converter won't lock
Pup E. Trucker #539535 February 14th 2012 5:17 pm
Joined: Jun 2009
Posts: 3,565
pooh-bah
Offline
pooh-bah
Joined: Jun 2009
Posts: 3,565
If your thermostat doesn't let the engine warm up properly it will cause problems too. My 1990 G20 had a bum thermostat and it wouldn't allow OD until 15 minutes into the drive and then for the next ten mintues it would drop in-out-in-out-in-out. It was a real pain! But if I was towing it would work great because the engine was laboring and getting hot. Once I changed the thermostat it worked great again! Proper OD operation all the time.... plus heat! cool


Josh Souders
Performance Inc

[Linked Image][Linked Image][Linked Image]


The voices in my head may not be real, but they have some good ideas!
Re: tourque converter won't lock
Pup E. Trucker #539557 February 14th 2012 5:42 pm
Joined: Jan 2001
Posts: 960
old hand
OP Offline
old hand
Joined: Jan 2001
Posts: 960
Thank you very much Colin.
I really appreciate the info.

I changed the electric plug and rebooted the
computer.
I took this tranny out of an 85'.
It was rebuilt and has been in 1 other van.
It worked well the first time, even though I had to change the speed sensor.
Thanks again for the help. I will check these
other possible problems.
This van is still too good to throw away.
Just got it inspected.
Yes 256654 mi, but she's a good girl lol
bow
Chevy, drive it till it drops!!! lol

Pup


Read your newspaper Daily

Moderated by  Astro 

Link Copied to Clipboard
Donate


Upcoming Events
discovery
Who's Online Now
0 members (), 17 guests, and 6 robots.
Key: Admin, Global Mod, Mod
Newest Members
TheDrunkenGunsmith, Jac, LOVclassics, ZenMuffin, Milkman530
12724 Registered Users
Top Posters (30 Days)
SDMickey 129
CatFish 25
frscke1 25
Wedgy 21
Forum Statistics
Forums68
Topics35,746
Posts537,916
Members12,725
Most Online177
May 8th, 2013

Powered by UBB.threads™ PHP Forum Software 7.7.4