th350 shift 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 05-25-2003, 01:36 AM
New Member
 
Last photo:
Join Date: May 2003
Location: Leeds - England - UK
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post th350 shift problem

my 56f100 has developed a 2-3 shift problem, that is there is no 2-3 shift. 1-2 is fine and there is no slip. In reverse you have to bring the reves up and then the trans drops into reverse, once in if you keep the engine revs reasonable there is no problem but if you let them drop right off you have to get them up again for the trans to drop back into reverse, when in gear it goes like a frieght train, I have been told that it could be the vac modulator and have checked out the shifter, the detent / kick down and all ok. Any help apreciated.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-25-2003, 02:11 AM
Kevin45's Avatar
Just one of the guys
 

Last journal entry: Garage Toys
Last photo:
Join Date: Jul 2002
Location: Urbana, Ohio
Age: 58
Posts: 3,058
Wiki Edits: 0

Thanks: 1
Thanked 15 Times in 15 Posts
Post

First thing I would do is check the modulator. from what you describe that sounds like what it is. Also check to make sure the hose to the modulator is not cracked anywhere and is connected to a good vacuum. Secondly, have you had the tranny apart recently and possibly dropped one of the check balls?

Kevin
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-25-2003, 04:45 AM
Tazz
 
Last photo:
Join Date: Jun 2001
Location: amherst,ohio
Age: 66
Posts: 2,049
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Ck the fluid. Ck the modulator and rubber hose for good hose and see how old the modulator is and maybe chang it it the hose is good/not cracked or loose and is tight at both ends/no leaks. Change fluid and filter and PRAY you didn't burn the Damn thing up.


Todd


Rat Rods Rule!
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-25-2003, 05:06 AM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Morris update 9-28-2014
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 8,130
Wiki Edits: 1659

Thanks: 358
Thanked 104 Times in 100 Posts
Cool

As you describe your problem; the vacuum modualator as nothing to do with your problem.

A problem with the vacuum modulator such as a bad hose, clogged line or ruptured diaphragm inside the modulator would cause problems with the 1-2 shift also.


The problem is with the direct (3rd gear) clutch

The direct clutch pack works with the low/reverse clutch pack to create the reverse gear.

If you have trouble in 3rd gear and reverse , it is the clutch pack. It is worn out, hard lip seals, or a problem with the sealing rings that is blowing off pressure.

The main line pressure of the tranny is boosted in reverse, that is why you can have a weak reverse , but no 3rd gear.




[ May 25, 2003: Message edited by: Crosley ]</p>
__________________
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
  #5 (permalink)  
Old 05-25-2003, 11:46 AM
New Member
 
Last photo:
Join Date: May 2003
Location: Leeds - England - UK
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

thanks for the help but I have changed the modulator with no difference and the reverse just hesitates rather than is week, once in the reverse is good. Does anybody know if there could be a valve problem, I have been informed that the 2-3 shift is effected by the valve body / gasket, this is also indicated in Chiltons manuals as the only fault on no 2-3 shift. The trans looks like it has been worked on as the sump gasket looks fresh but I have not had the vehicle long so have no history. the only fault on the whole vehicle is no drop into third, it does not even try to drop afer the 1-2 change. I have tried running the box in all the manual shifter positions and still can only achieve 1-2 and reverse, I have found out recently that the vehicle had been stood for 5yrs prior to my purchase but am asured it was running strong when removed from the road.
Help apreciated. <img src="confused.gif" border="0">
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-25-2003, 01:02 PM
Deuce's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Choosing a trailer
Last journal entry: Jan 13 2013
Last photo:
Join Date: Aug 2002
Location: Deuceland USA
Age: 66
Posts: 5,657
Wiki Edits: 6

Thanks: 0
Thanked 9 Times in 9 Posts
Post

[quote]Originally posted by Crosley:
<strong>As you describe your problem; the vacuum modualator as nothing to do with your problem.

A problem with the vacuum modulator such as a bad hose, clogged line or ruptured diaphragm inside the modulator would cause problems with the 1-2 shift also.


The problem is with the direct (3rd gear) clutch

The direct clutch pack works with the low/reverse clutch pack to create the reverse gear.

If you have trouble in 3rd gear and reverse , it is the clutch pack. It is worn out, hard lip seals, or a problem with the sealing rings that is blowing off pressure.

The main line pressure of the tranny is boosted in reverse, that is why you can have a weak reverse , but no 3rd gear.




[ May 25, 2003: Message edited by: Crosley ]</strong><hr></blockquote>



I bet it is JUST LIKE CROSLEY SAID......

bailey40ford..........Crosley does this for a living.......listen up..... he knows.....

Unlike a lot of people who post here and Guess (which is what I would be doing on a automatic transmission not working question) Crosley will not post unless it is in his range of experience.....or knowledge.


.
__________________


"I won't be wronged . I won't be insulted, and I won't be laid a hand on. "






Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-25-2003, 05:23 PM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Morris update 9-28-2014
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 8,130
Wiki Edits: 1659

Thanks: 358
Thanked 104 Times in 100 Posts
Post

[quote]Originally posted by bailey40ford:
<strong> In reverse you have to bring the reves up and then the trans drops into reverse, once in if you keep the engine revs reasonable there is no problem but if you let them drop right off you have to get them up again for the trans to drop back into reverse, when in gear it goes like a frieght train, </strong><hr></blockquote>


=================== If the above does not describe a weak reverse, then I don't know what to call it.

<img src="confused.gif" border="0">
__________________
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
  #8 (permalink)  
Old 05-25-2003, 06:19 PM
adtkart@aol.com
 
Last photo:
Join Date: Oct 2002
Location: Newport News, VA
Posts: 3,220
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

It seems that the standard answer on this site for almost any problem with a TH350 is a bad modulator. If that doesn't correct the problem, it must be a pluged filter. PEOPLE, if the filter is pluged, you have a serious problem. The only thing to plug the filter in an automatic transmission is parts of that trans. If the filter is pluged and you change it and keep driving(if possible), do it while looking for another trans. You are destroying the one that you have. The modulator will not keep a transmission from engaging! On a TH350, it controls all forward shifts. It has nothing to do with reverse! If you have to rev up the engine for it to engage in reverse, and it engages in 1st, there is a serious problem. It takes considerably higher line pressure for reverse. That is why you are needing to rev it up. If Crosley gives advise, he is doing so to help you. He knows what he is talking about. PAY ATTENTION!
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 02:05 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.