th350 shift point - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 09-09-2010, 07:11 PM
Registered User
 
Last photo:
Join Date: Aug 2010
Location: texas
Posts: 261
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
th350 shift point

alright i asked this in the engine tech. i did not get any replies so i guess they thought i was crazy. The problem is i already know im crazy, i just want to understand why this happened... lol. anyway. Just went from a stock 359 with headers to a rebuilt 350 with big valve heads and higher compression. With the old motor the transmission would shift hard into second. With the new motor it doesnt jerk as hard. Itd a rebuilt trans only a couple years old, and the fluid is full of course. i was a little weary to post this out of fear of looking like a fool. I just dont understand i would think that the new motor and power increase would make it shift harder? is there something im missing?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-09-2010, 07:23 PM
Aerotech's Avatar
Registered User
 
Last photo:
Join Date: Oct 2009
Location: Brandon, MS
Posts: 74
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
You have less vacuum with the new motor, which is one factor that determines when it shifts. Nothing wrong with a softer shift, probably better for everything in the long run. Make sure the vacuum source for the tranny is from the manifold behind the carb. You will probably not get the firm stock shifts with big-valve heads.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-10-2010, 09:32 PM
Registered User
 
Last photo:
Join Date: Aug 2010
Location: texas
Posts: 261
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
that would make sense but i forgot to mention one thing. i have the vaccuum thing for shifting disconnected at the moment and am shifting it manually because it was going bad when i switched motors
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-11-2010, 01:12 AM
Aerotech's Avatar
Registered User
 
Last photo:
Join Date: Oct 2009
Location: Brandon, MS
Posts: 74
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
You must use the vacuum line if you expect a TH350 to shift properly. It knows when to shift better than you do, and if you override it and shift manually, you are losing performance. You can hold off the shifts a little with modulator and governor adjustments, but just letting it do its thing is usually best.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-11-2010, 01:28 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Leaving the kickdown cable disconnected is sometimes done, but you should use the modulator. If the modulator is "going bad", replace it.

You may be experiencing a different shift 'feel' because the new engine is generating more torque, causing the converter to stall a bit higher and this can also make the shifts feel softer- but the main thing is the trans needs to be fully functional, as in not needing rebuilt.
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
TH350 delayed manual 1-2 shift RocketSwede Transmission - Rearend 17 10-12-2008 12:26 AM
low shift point elcaminodragster Transmission - Rearend 1 04-28-2007 08:20 PM
4l60e shift point question silm man Transmission - Rearend 2 02-19-2006 03:23 AM
Late shift point bct Transmission - Rearend 2 05-27-2005 07:59 PM
c10 - th350 to 700r4 swap column shift 70chevyc10 Transmission - Rearend 7 10-25-2004 09:35 AM


All times are GMT -6. The time now is 07:01 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.