T-400 Modulator or Governor Upshift? - 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 03-29-2010, 11:24 PM
454headache's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Washington
Age: 34
Posts: 237
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
T-400 Modulator or Governor Upshift?

At full throttle my turbo 400 upshifts at 4,500 rpm. I want it to upshift at at least 5,000, maybe even 5,500. I know that the modulator controls upshifts, but only up to WOT I think. After that, the springs in the Governor decide when to upshift right?

So should I get different springs for the governor or adjust the modulator? If I adjust the modulator won't all upshifts be higher up in the rpm range? I mean, If say I adjust it to 5,500 WOT upshift, won't my partial/cruising throttle upshifts also be up much higher?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-30-2010, 12:36 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
Quote:
Originally Posted by 454headache
At full throttle my turbo 400 upshifts at 4,500 rpm. I want it to upshift at at least 5,000, maybe even 5,500. I know that the modulator controls upshifts, but only up to WOT I think. After that, the springs in the Governor decide when to upshift right?

So should I get different springs for the governor or adjust the modulator? If I adjust the modulator won't all upshifts be higher up in the rpm range? I mean, If say I adjust it to 5,500 WOT upshift, won't my partial/cruising throttle upshifts also be up much higher?
An adjustable modulator might get you an extra 5-6 MPH at WOT, less (maybe 2-3 MPH) at cruise speeds.

The way to get higher WOT shifts with the shifter in "D" is by modifying the GOVERNOR.

You can also do an easy mod to the 1-2 shift valve to allow you to hold first until you manually shift to second. But be aware that it also allows downshifts at ANY speed. The way it is stock, if you pull the shifter into second from "D" at 100 MPH- nothing will happen until the road speed drops to low enough for second gear to engage.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-30-2010, 06:30 AM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Bar under the dash
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 8,092
Wiki Edits: 1659

Thanks: 340
Thanked 102 Times in 98 Posts
Quote:
Originally Posted by 454headache
At full throttle my turbo 400 upshifts at 4,500 rpm. I want it to upshift at at least 5,000, maybe even 5,500. I know that the modulator controls upshifts, but only up to WOT I think. After that, the springs in the Governor decide when to upshift right?

So should I get different springs for the governor or adjust the modulator? If I adjust the modulator won't all upshifts be higher up in the rpm range? I mean, If say I adjust it to 5,500 WOT upshift, won't my partial/cruising throttle upshifts also be up much higher?

Your understanding of the modulator and governor operations is incorrect.

The governor weights and springs work together

The springs in the governor control shift points primarily at light throttle. Changes to the springs affect shift points more up to 35 mph area depending on gear ratio - tires ,etc.

The weights affect higher speed shift points more than the springs do.

Later WOT shift = higher RPM will happen by lightening the weights ( inner) on the governor.

The vacuum modulator affects mostly th e light throttle shift points. At WOT the vacuum will be near zero and the modulator will be ineffective. This will have main line pressure raised.

I would suggest you prchase a kit with different weights and springs to modify your governor. Or simply start grinding on the inner weights for later WOT shift points.

The lighter weights will affect light throttle shifts slightly on the t-400 trans , but mostly the higher speed shift points

__________________
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-30-2010, 12:20 PM
454headache's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Washington
Age: 34
Posts: 237
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
So to grind down the weights, you just remove the gov cover, and they come out? How much to grind to raise the shift point about 1,000 rpm?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 04-05-2010, 10:29 PM
454headache's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Washington
Age: 34
Posts: 237
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Best cheap mod ever. I spent a half hour jacking up the truck and grinding on the inner weights, bought a box of 6D nails to replace the pins, and now I have great WOT at 5,500.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 04-06-2010, 04:48 AM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Bar under the dash
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 8,092
Wiki Edits: 1659

Thanks: 340
Thanked 102 Times in 98 Posts
Quote:
Originally Posted by 454headache
Best cheap mod ever. I spent a half hour jacking up the truck and grinding on the inner weights, bought a box of 6D nails to replace the pins, and now I have great WOT at 5,500.

Good to see you have adjusted the shift points and you learned a little bit too


__________________
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.
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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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
T-350 governor/modulator? sabino56 Transmission - Rearend 9 10-11-2013 06:25 PM
T-400 - No Manual Upshift Mr. Fixit Transmission - Rearend 1 11-21-2011 11:54 AM
th 400 1-2 upshift w/lever in 1st grayghost52 Transmission - Rearend 3 07-05-2011 09:38 AM
T-400 governor gear breaks off 63droptopnova Transmission - Rearend 7 05-30-2007 06:10 PM
th400 won't upshift...not modulator msc66 Transmission - Rearend 1 08-28-2005 09:58 PM


All times are GMT -6. The time now is 04:07 PM.


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.