Chevy & GMC Vans

Is there way to stop the TC from locking up. Most of my driving is high speed through city streets and the something just feels wrong. I ordered a rebuilt valve body with upgrades to fix the P1870 code. Its a 98 with 140,000 so far.

Mike in FL

You don't want the TC unlocked all the time as it make huge amounts of heat while unlocked and will eventually toast the trans. In your 98, the TC locks in 3rd and 4th (OD) only. 1st and 2nd do not lock up.

LiftedAWDAstro wrote:You don't want the TC unlocked all the time as it make huge amounts of heat while unlocked and will eventually toast the trans. In your 98, the TC locks in 3rd and 4th (OD) only. 1st and 2nd do not lock up.

I'm gonna do my 1st shift kit / valve body Saturday.........if I'm not back in 3 days please send help!!!!!

Mike

LiftedAWDAstro wrote:You don't want the TC unlocked all the time as it make huge amounts of heat while unlocked and will eventually toast the trans. In your 98, the TC locks in 3rd and 4th (OD) only. 1st and 2nd do not lock up.

Is that changed in later years?

I think it changed when they went the electronically controlled trans.

Do you know what changed?

Nope...I just know my 95, 98 and 2003 vans all locked up the TC in 3rd and 4th.

LiftedAWDAstro wrote:Nope...I just know my 95, 98 and 2003 vans all locked up the TC in 3rd and 4th.

How can one tell if the Torque Converter is locked up?


Lump

I'm trying to figure out how to do that with Xgauge codes on my Scanguage2 right now. I found PID's for transmission input and output speed, but the numbers don't make any sense yet.

Lumpy wrote:

LiftedAWDAstro wrote:Nope...I just know my 95, 98 and 2003 vans all locked up the TC in 3rd and 4th.

How can one tell if the Torque Converter is locked up?


Lump

If you had a tach you'd see the rpm's drop, but even with a tach you should still feel a slight drop in engine speed

astrozam wrote:

Lumpy wrote:

LiftedAWDAstro wrote:Nope...I just know my 95, 98 and 2003 vans all locked up the TC in 3rd and 4th.

How can one tell if the Torque Converter is locked up?


Lump

If you had a tach you'd see the rpm's drop, but even with a tach you should still feel a slight drop in engine speed

I guess I need more details, please. Engine speed drop when, exactly? I can sense engine speed drop every time the trans shifts up. Is there another drop a moment later?


Lump

I don't know an exact speed for you're van, have a look at this thread from a while back...
http://www.astrosafarivans.com/bb2/view ... 52&start=0

Replaced valve body.......kinda easy once I found all 7 balls. I was shocked to find the pan so clean with just a teaspoon of gray stuff on the magnet. Now it locks up and shifts smooth...for now. Next project engine in a 99.

Mike