th350 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 10-09-2007, 06:19 AM
Member
 
Join Date: Nov 2004
Location: Maryland
Age: 62
Posts: 71
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
th350 problem

The engine runs too high an rpm to pull the car, as though the converter has a high stall. The pan had a lot of debris. The trans oil didn't smell burned. How do I determine if the transmission has a bad seal or if there is a torque convertor problem. The symptoms came on rather quickly.

    Advertisement

Last edited by firebird_red; 10-11-2007 at 12:02 AM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-10-2007, 06:48 AM
Registered User
 
Join Date: Oct 2006
Location: VIRGINIA
Posts: 690
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
350

The engine runs too high an RPM? do you mean it feels like it slips while trying to leave from a stop?

You state that the converter feels like it has a high stall, which I assume is different now than it was before this problem occured, so I would think that the trans is either slipping or taking off in the wrong gear.

Even though you say the fluid was not burnt, you do say there was a lot of debris in the pan.

I suspect this was a precipitous failure, something broke and dumped a lot of trash in the trans, the fluid did not have a chance to get nasty.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-10-2007, 08:51 PM
Registered User
 
Last photo:
Join Date: Aug 2007
Location: Florida
Posts: 176
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
sounds like he may have broke the low roller
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-11-2007, 12:01 AM
Member
 
Join Date: Nov 2004
Location: Maryland
Age: 62
Posts: 71
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The car is sluggish in all gears as though it is slipping. Shifts are sloppy and vague, but all gears are there and shift at roughly the correct speeds. The car is just unresponsive to the throttle, with the engine picking up rpm while the car just coasts. It's not my car, but I understand it started without warning rather suddenly. I may help put in a kit because the frictions are ground up and in the pan. I wanted to be sure there wasn't a converter issue or something else that also needs attention while it's apart.

By low roller, do you mean a sprag? Would that effect all gears?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-11-2007, 07:37 AM
Registered User
 
Last photo:
Join Date: Aug 2007
Location: Florida
Posts: 176
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
no the low roller would only affect first sounds like you have a problem in the forward circuit or a fluid pressure issue. if ther is debris in the pan you will be looking at a overhaul there really is nothing you can do at this point to make it all better.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-11-2007, 10:17 PM
DHMag's Avatar
Registered User
 
Last photo:
Join Date: Jun 2005
Location: InCahoots, Texas
Posts: 302
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
when a low roller goes away, it sounds like marbles in the case.

is there any history on this transmission ?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-28-2007, 01:02 AM
Member
 
Join Date: Nov 2004
Location: Maryland
Age: 62
Posts: 71
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The transmission is in a 69 Firebird with unknown miles perhaps well over 100K on this particular transmission. It isn't making any unusual sounds. There was some debris in the pan, but the oil didn't smell burned. Oil was also not as bright red as I would have expected. The slipping, as though the converter had a high stall began suddenly. The car has hardly been driven since so as not to cause additional damage.

We figured it would need a rebuild. I'm looking for advice on other things to watch out for when we open this up. I've gone through a th400, and I guess this one's not much different inside except building the rear clutch inside the case. But installing a kit doesn't mean you are good at diagnosing the cause.

Once the frictions have left junk in the pan, there's bound to be junk in the converter. Is this a concern? Can the converter be flushed out? Is there any reason to get a remanufactured converter before this goes back together. This was a lot of work getting the engine and trans out and not something he wants to repeat. So we need to make no mistakes with the repairs.

The owner is deciding which master kit to buy. He pulled the engine and trans out this afternoon.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-28-2007, 05:45 AM
richard stewart 3rd's Avatar
Registered User
 

Last journal entry: 351W rebuild
Last photo:
Join Date: Jan 2006
Location: tremont, pa.
Age: 69
Posts: 2,217
Wiki Edits: 0

Thanks: 13
Thanked 15 Times in 14 Posts
Hi,
The fluid doesn't smell burnt because it hasn't
had time to get that far yet, but the evidence
is there "Fluid not as bright red as I would
have expected" thats because the friction material
is burning due to slippage, causing the fluid to
turn dark. You asked about the converter,
You either need to flush it out, or use a rebuilt,
That crap that was in your pan, is in the converter
& lines as well, & if you don't either flush it or replace it,
it will be traveling through your new trans. causing
damage.
Good luck,
rich
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-29-2007, 08:30 PM
70 ElCam's Avatar
Rebel with a Chevy
 
Join Date: Oct 2007
Location: South of the Mason Dixon
Age: 52
Posts: 87
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sounds like the converter . When you say debris , you didn't mention if it was clutch material or shiny metal pieces that may have come from the converter fins. If you just have to have that converter have it gone through, if not get a rebuilt converter. 350s aren't mystical , just replace all the intermediate sprag elements and springs. Also a hardened race. Check the low roller for any cracks or heat build up. Replace the whole center support if an signs of drag there.
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
th350 problem 383silverado Transmission - Rearend 2 06-18-2007 09:16 PM
strange th350 problem 49chevysd Transmission - Rearend 17 10-13-2005 04:05 PM
Please Help, Problem with TH350 kehi66 Transmission - Rearend 3 06-20-2005 01:34 PM
th350 speedometer problem john69 Transmission - Rearend 4 06-17-2003 06:38 PM
th350 problem..... oldcarguy85 Transmission - Rearend 2 04-24-2002 04:06 PM


All times are GMT -6. The time now is 07:48 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.