TC lockup

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Topic author
applianceguy
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TC lockup

Post by applianceguy »

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

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Re: TC lockup

Post by LiftedAWDAstro »

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.
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2005 Nissan Sentra 1.8S Special Edition

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Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
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Topic author
applianceguy
I am merely driving my van
I am merely driving my van
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Re: TC lockup

Post by applianceguy »

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 ](*,)
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Re: TC lockup

Post by MountainManJoe »

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?

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Re: TC lockup

Post by LiftedAWDAstro »

I think it changed when they went the electronically controlled trans.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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Re: TC lockup

Post by MountainManJoe »

Do you know what changed?

LiftedAWDAstro
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Re: TC lockup

Post by LiftedAWDAstro »

Nope...I just know my 95, 98 and 2003 vans all locked up the TC in 3rd and 4th.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

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Re: TC lockup

Post by Lumpy »

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?


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Re: TC lockup

Post by MountainManJoe »

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.

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Re: TC lockup

Post by astrozam »

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

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Re: TC lockup

Post by Lumpy »

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?


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Re: TC lockup

Post by astrozam »

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

Topic author
applianceguy
I am merely driving my van
I am merely driving my van
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Joined: Wed May 05, 2010 6:59 pm

Re: TC lockup

Post by applianceguy »

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
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