turbo 400 problem - 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 09-06-2004, 11:14 AM
JamesRS's Avatar
Member
 
Last photo:
Join Date: Dec 2002
Location: Palm Springs, Ca.
Age: 51
Posts: 175
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
turbo 400 problem

Hi all, I'm having problems with my turbo 400 not shifting correctly. When I put the trans in drive and accelerate, it stays in first gear up to about 25 mph. Even when I accelerate slowly. It seems like the kickdown switch is activated, but I don't have any kickdown hooked up. I'm not that familiar with 400's, I've only worked on 350's. Any idea's as to what could be causing this? Vacuum modulator, stuck switch on the trans or something. Any help would be appreciated.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-06-2004, 03:38 PM
stu stu is offline
Member
 
Last photo:
Join Date: Aug 2004
Location: Saskatchewan
Age: 73
Posts: 428
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Does it shift at all?
If there is no shift at any speed the governor could be stuck or the driven gear stripped.
Or.
It could be either a vacuum or electrical switch concern.
Check for good vacuum at the modulator.
If that is ok then apply 12 volts to the connector at the transmission and listen for a click. If it clicks you have other problems.
No click.
Drop the pan.
Undo the connector, remove the two small bolts.
Remove the cover from the switch and clean it out.
It should click when 12 volts are applied.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-06-2004, 06:50 PM
JamesRS's Avatar
Member
 
Last photo:
Join Date: Dec 2002
Location: Palm Springs, Ca.
Age: 51
Posts: 175
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yeah Stu, it shifts at about 2500 - 3000 RPM's when I'm not getting on it. If I put my foot into it it shifts much higher then that. I checked the modulator and the diaphragm is good. The only connector I see is for what I thought was the reverse lights, and it's disconnected. I don't have any electrical wires connected to the trans.


After I checked the vacuum modulator, I noticed that it had an adjusting screw in the middle of the vacuum port, so I backed it out a couple of turns (4) and I noticed that the shifting seemed to occur a little sooner, but still not where you would consider correct.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-06-2004, 09:09 PM
stu stu is offline
Member
 
Last photo:
Join Date: Aug 2004
Location: Saskatchewan
Age: 73
Posts: 428
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Measure the vacuum. Just sticking your finger over the end isn't good enough.
The switch could be open which would raise the shift points.
Try applying 12 volts to it and listen for a click.
It should click on and off as you apply and release the voltage.
Don't screw with the adjuster at the modulator.
400's are usually set very good.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-07-2004, 04:58 PM
JamesRS's Avatar
Member
 
Last photo:
Join Date: Dec 2002
Location: Palm Springs, Ca.
Age: 51
Posts: 175
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for the reply Stu. I checked the vacuum modulator by removing it and placing a vacuum on it. I observed the internal plunger depress and hold. I figured that the internal diaphram is good. I'll check the switch tonight and let you know if I hear a click when I apply 12 volts.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 09-07-2004, 06:06 PM
stu stu is offline
Member
 
Last photo:
Join Date: Aug 2004
Location: Saskatchewan
Age: 73
Posts: 428
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
What vacuum are you getting at the valve?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 09-07-2004, 09:24 PM
sbchevfreak's Avatar
Licenced Automotive Technician
 
Last photo:
Join Date: Feb 2004
Location: Land of big Easter eggs, Alberta
Age: 34
Posts: 1,609
Wiki Edits: 0

Thanks: 13
Thanked 9 Times in 9 Posts
i'm with stu. get a guage on the vacuum line and see what you've got.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 09-08-2004, 10:49 AM
JamesRS's Avatar
Member
 
Last photo:
Join Date: Dec 2002
Location: Palm Springs, Ca.
Age: 51
Posts: 175
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well Stu, I checked the kick down switch by applying 12v and it clicked like I guess it's supposed to.

As for Vacuum, I have the line running straight from the intake with no "T" connectors or anything, so the trans is getting straight manifold vacuum. I don't have a gauge handy to check the exact vacuum amount though. Since it is getting straight max vacuum from the engine the only option I could see would be to get a modulator that operated on a lower vacuum?
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 09-08-2004, 12:09 PM
stu stu is offline
Member
 
Last photo:
Join Date: Aug 2004
Location: Saskatchewan
Age: 73
Posts: 428
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Does it have vacuum at the valve?
There aren't any modulators that will run on much lower vacuum.
You could have governor problems.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 09-08-2004, 02:46 PM
JamesRS's Avatar
Member
 
Last photo:
Join Date: Dec 2002
Location: Palm Springs, Ca.
Age: 51
Posts: 175
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yeah, I have vacuum at the valve. Governor problems..... Well we do have Arnold as Governor now....ha!

Sorry, I won't do that again.

Anyhow, how would I be able to check for governor problems?
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 09-08-2004, 03:05 PM
stu stu is offline
Member
 
Last photo:
Join Date: Aug 2004
Location: Saskatchewan
Age: 73
Posts: 428
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
There is a square cover with 4 bolts.
Remove the bolts and pull the governor out.
Check the gear for wear.
Hold the governor by the gear and let weights fall.
Pinch the weights and watch the small valve inside move.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 10-03-2004, 01:10 PM
JamesRS's Avatar
Member
 
Last photo:
Join Date: Dec 2002
Location: Palm Springs, Ca.
Age: 51
Posts: 175
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I know it's been a while since I replied to this post, but I finally had the chance to pull the governor and check the springs. Rather then lean on my knowledge of how loose or tight the springs should be, and how much wear there is on the gear. I just sprang the $20.00 and replaced governor with a new one. The bad news is the transmission still does the same thing. When I start out it up shifts fine from 1-2, and 2-3, but when its in it's final gear (3rd), if I put my foot in it a little, it down shifts back into second.

Don't know where to go from here. Any more suggestions?
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 10-03-2004, 02:54 PM
Member
 
Join Date: Aug 2003
Location: calgary canada
Posts: 727
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
2nd gear shift valve would be my thought but lets see what cosby has to say
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 10-03-2004, 04:27 PM
stu stu is offline
Member
 
Last photo:
Join Date: Aug 2004
Location: Saskatchewan
Age: 73
Posts: 428
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
When you put your foot in it a bit you are decreasing vacuum to the valve. This will quite often cause a down shift.
Please measure the vacuum at the valve.
I want you to come back with a number.
At idle and off idle.
I don't know how to state it any easier.
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



All times are GMT -6. The time now is 04:24 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.