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

TH 400 Problem Maybe?

Thread Tools
 
Search this Thread
 
Old Aug 2, 2009 | 03:27 PM
  #1  
blown 346's Avatar
Thread Starter
TECH Fanatic
iTrader: (25)
 
Joined: Jan 2003
Posts: 1,426
Likes: 0
From: Loves park/rockford
Default TH 400 Problem Maybe?

Heres the jist of things.

91 Camaro Z28
383 Stroker
TH400
B&M 2400 Convertor
3600 GVW Cooler.

The trans shifted fine with my old motor (406) no problems what so ever. The car shifted on its own at about 2500 or so casually driving.

Dropped in my 383 and now the trans shifts at 4000 from first to second, 3500 from second to third. I just drained and refilled the tranny last night, it is full. The trans fluid doesnt smell burnt. The car will shift from park to reverse, drive 1st, 2nd 3rd with no issues at a stand still. The car drives fine, and shifts decently firm on the 1 to 2 shift, minus the 4000 shift point.

Im almost thinking the motor has something to do with it, but am not sure.

Any help would be appreciated.
Reply
Old Aug 2, 2009 | 06:10 PM
  #2  
blown 346's Avatar
Thread Starter
TECH Fanatic
iTrader: (25)
 
Joined: Jan 2003
Posts: 1,426
Likes: 0
From: Loves park/rockford
Default

Anyone?
Reply
Old Aug 2, 2009 | 06:14 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

Check that you have good engine vaccume to the modulator ?
__________________
Built..PerformaBuilt..Tough

Call 888-744-6542


Reply
Old Aug 2, 2009 | 07:16 PM
  #4  
performabuilt2's Avatar
LS1Tech Sponsor
 
Joined: Aug 2007
Posts: 380
Likes: 0
Default

i would think that maybe you have a different vacumm signal from different motors and cam profile high vacumm low shift points, low vacumm higher shift points.....with same governor setup ....the modulator is adjustable though or you may have to play with the governor...but as frank saids make sure the vacumm is hooked up sounds like its not
__________________
https://ls1tech.com/forums/image.php...ine=1194732633
Free Cooler, Free shipping always, 2 year warranty Trans/Coverter combos, No Core or Core charge, $150 LS1 core buy back, All trans Dyno Tested to Be sure it works when you get it.Customer videos, Tech Thread, Open 7 Days a Week! Call or http://opi.yahoo.com/online?u=performabuilt&m=g&t=2Click Banner for Website.
Not Just Built.....PerformaBuilt!

Reply
Old Aug 3, 2009 | 03:43 AM
  #5  
blown 346's Avatar
Thread Starter
TECH Fanatic
iTrader: (25)
 
Joined: Jan 2003
Posts: 1,426
Likes: 0
From: Loves park/rockford
Default

Went over the vacuum lines and found one that had a slice in it. Replaced it and all is good. Thanks.
Reply
Old Aug 3, 2009 | 08:14 AM
  #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

Cool glad could help
__________________
Built..PerformaBuilt..Tough

Call 888-744-6542


Reply




All times are GMT -5. The time now is 09:17 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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