Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
Sponsored by:
Sponsored by:

too much line pressure?!?

Thread Tools
 
Search this Thread
 
Old Jun 10, 2008 | 07:33 PM
  #1  
lt170chevelle's Avatar
Thread Starter
TECH Fanatic
iTrader: (2)
 
Joined: Jul 2006
Posts: 1,153
Likes: 1
From: BS,TX
Default too much line pressure?!?

i have been having problems pecking the rev limiter in 1st to 2nd for a while now .i have a shift kit in a 4l60e and upped the line press in the table by 5 psi. my question is..is there a chance i am getting too much line pressure? also when i replaced the tranny about a year ago, i was getting a very delayed shift through all gears and was told to turn the torx something on the valvebody to increase line pressure to compensate i think was an 1/8th to 1/4 of a turn.could i have too much now? i have been gradually lowering the shift tables with no luck yet.will too much pressure make it hang in gear in between 1st to 2nd shift?
Reply
Old Jun 10, 2008 | 07:43 PM
  #2  
JimsWS6's Avatar
TECH Apprentice
iTrader: (1)
 
Joined: Oct 2005
Posts: 324
Likes: 0
From: Norwich, NY
Default

I have a vette servo, changed the pressure valve spring, and vette 1-2 spring and if i horse my truck alot she'll shift 1-2 around 4500 WOT. I have to disconnect the battery and then it'll go right back up to 5300.

But my truck will churp the tires sometimes in the 1-2 shift under WOT. Probly not too good for it, considering it has 220,000 miles


So I think it is possible, it backs off some pressure to help reduce stress I feel. We'll wait for a pro to jump in on it
Reply
Old Jun 10, 2008 | 08:26 PM
  #3  
performabuilt's Avatar
LS1Tech Sponsor
15 Year Member
Liked
Loved
Community Favorite
iTrader: (25)
 
Joined: Aug 2006
Posts: 10,854
Likes: 80
From: BLOOMSBURG PA
Default

Yes excessive line could cause a no shift issue at WOT this can happen when so much fluid is be sent to the solenoids that they cant vent fast enough. And is you have the line raise both electronically and with the PCS screw and with a boost valve from the shift kit its very possible this is the case. I would disconnect the harness from the trans with a pressure gauge installed and see just what the max line pressure is, IMO it should never exceed 230 PSI
__________________
Built..PerformaBuilt..Tough

Call 888-744-6542


Reply
Old Jun 10, 2008 | 09:36 PM
  #4  
lt170chevelle's Avatar
Thread Starter
TECH Fanatic
iTrader: (2)
 
Joined: Jul 2006
Posts: 1,153
Likes: 1
From: BS,TX
Default

ok thanks. when i can get my hands on a guage i will definitely have to see what its doing. About when would max line pressure kick in? in gear revved? Or certain rpm in neutral?what will happen if i drop max line pressure in my tables by like ten psi?
Reply
Old Jun 10, 2008 | 09:42 PM
  #5  
02c6ss's Avatar
Teching In
iTrader: (5)
 
Joined: Apr 2005
Posts: 37
Likes: 0
Default

Is it a weak 1-2 shift kind of like it slides in? Once it goes in 2nd does it hold or slip?? I had a problem that sounds like yours. I decided to install the trango hd kit with the fairbanks super servo and aluminum 1-2 and forward accumulator pistons. I ended up that one of the factory plastic accumulator pistons had a crack in it which was bleeding off the pressure and causing the weak 1-2 shift. Now the thing shifts better than ever and saved myself 1800 dollars. The pistons were only 20 bucks off ebay for both of them so its worth a try. Hope this can save you some cash!!
Reply
Old Jun 10, 2008 | 09:46 PM
  #6  
performabuilt's Avatar
LS1Tech Sponsor
15 Year Member
Liked
Loved
Community Favorite
iTrader: (25)
 
Joined: Aug 2006
Posts: 10,854
Likes: 80
From: BLOOMSBURG PA
Default

Originally Posted by lt170chevelle
ok thanks. when i can get my hands on a guage i will definitely have to see what its doing. About when would max line pressure kick in? in gear revved? Or certain rpm in neutral?what will happen if i drop max line pressure in my tables by like ten psi?

You can adapt and old A/C high side gauge to work and to see max line simply unplug harness from trans with it running and test line. I usually test in OD position and at idle it should not rise with engine rpm with harness unpluged.

And whats mentioned above is also a distinct possibility
__________________
Built..PerformaBuilt..Tough

Call 888-744-6542


Reply
Old Jun 10, 2008 | 10:01 PM
  #7  
lt170chevelle's Avatar
Thread Starter
TECH Fanatic
iTrader: (2)
 
Joined: Jul 2006
Posts: 1,153
Likes: 1
From: BS,TX
Default

well it shifts good unless im at wot.quick shifts under normal driving conditions and doesnt slip.also when i installed the shift kit i noticed all of my pistons are aluminum no plastic ones.but maybe a bad oring..no tellin at this point. i will see if i can find a guage laying around and go from there.
Reply
Old Jun 19, 2008 | 09:16 PM
  #8  
Jeff 97 Formula's Avatar
TECH Regular
15 Year Member
 
Joined: May 2005
Posts: 470
Likes: 4
Default

I hear it's not good to increase line pressure and shift kit (do one or the other, not both).
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old Jun 19, 2008 | 11:04 PM
  #9  
FLT's Avatar
FLT
FormerVendor
iTrader: (1)
 
Joined: Sep 2005
Posts: 6,620
Likes: 4
From: Wood Dale, Illinois
Default

Originally Posted by Jeff 97 Formula
I hear it's not good to increase line pressure and shift kit (do one or the other, not both).

I wish I had a dollar for every time I have said that on the phone to a customer. One or the other not both. However tuning will not effect max line pressure. Meaning how much pressure the trans is capable of making. The trans depending how it is setup, will only make so much pressure. I feel that 210-220 max psi is perfect when hot. Most builders will crank the epc up to get more pressure and IMO you will yield to much pressure when doing this. Vince
Reply
Old Jun 20, 2008 | 12:55 PM
  #10  
98 T/A raptor's Avatar
TECH Apprentice
iTrader: (2)
 
Joined: Nov 2003
Posts: 314
Likes: 1
From: Jacksonville
Default

this is good to know
Reply




All times are GMT -5. The time now is 12:47 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE