TH 350 Slipping - 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 12-18-2005, 10:17 AM
Jeeps Are Us!
 

Last journal entry: The Paint Shop
Last photo:
Join Date: Jan 2005
Location: Tehran, Iran
Age: 39
Posts: 300
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
TH 350 Slipping

Hello Everyone!

I've just faced a wierd problem with my tranny.
Actually, yesterday it was raining and I thought that rear end is slipping on the road, but I found out that all of a sudden my tranny is slipping and it is heating up. It went upto 200 almost!!!

So I checked the fluid, it's full.
It looks fine, and it doesn't smell like a burned out tranny fluid.

This morning when I ran the car it's a '70 1/2 Camaro SS 350, it was o.k. again.
As I drove it for about an hour of so again, I faced the same problem. It gets heated and it starts slipping.

When I'm in a steep road and when in Drive, as soon as I take my foot of the break, the car eventhough in Drive it starts to go backward down the road. So for the car to start moving forward I'd have to almost rev. about 3000 rpm to move forward.

What could this be? It's some kind of oil pressure loss?
I'm running TCI Pro Super Kit and B&M Super Cooler.

Could it be the clutch plates? As I said the oil is in perfect condition.

Thanks for your advises. We are having a Quarter Mile contest in two weeks, I'd have to get over this a.s.a.p.

Bye,
Houman SS '70

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-18-2005, 08:09 PM
Frmly sc*ot.
 
Join Date: Apr 2005
Location: Rockville, Md
Posts: 90
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The trans could just be worn out.
Check the fluid level and the throttle valve setting.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-18-2005, 08:19 PM
Registered User
 
Last photo:
Join Date: Aug 2005
Location: BAILEY N.C.
Posts: 41
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Check the band adjustment,band could be worn and need to be readjusted,Or need a new one
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-19-2005, 03:07 PM
Jeeps Are Us!
 

Last journal entry: The Paint Shop
Last photo:
Join Date: Jan 2005
Location: Tehran, Iran
Age: 39
Posts: 300
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Valve Body O.K.

Hello Again,

Today, I opened up the oil pan, the oil was just in perfect condition, and there were no worn out clutch particles in the filter and/or oil pan at all!!!
As I mentioned earlier this tranny has been rebuilt for about three months ago or app. 1000 miles.

So I opened the valve body, checked all the valves and springs. Everything was just fine.
The vacuum modulator had sucked in some trans fluid, I don't know why!!!
Tomorrow I'm gonna change the modulator, but does it have anything to do with this problem?

So, now, what do you guys suggest?
Should I take out the tranny and open up the front pump, bands, etc.?

Or could it be the Torque Converter?

Any guesses, advises.
BTW, I changed the fluid as well and pumped up air through all the cooler lines too. So there should be no problem there either.

Thanks in advance for your assistance.

Houman SS '70
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-19-2005, 05:30 PM
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: 8,060
Wiki Edits: 1659

Thanks: 316
Thanked 97 Times in 94 Posts
Quote:
Originally Posted by Houman SS '70
Hello Again,

Today, I opened up the oil pan, the oil was just in perfect condition, and there were no worn out clutch particles in the filter and/or oil pan at all!!!
As I mentioned earlier this tranny has been rebuilt for about three months ago or app. 1000 miles.

So I opened the valve body, checked all the valves and springs. Everything was just fine.
The vacuum modulator had sucked in some trans fluid, I don't know why!!!
Tomorrow I'm gonna change the modulator, but does it have anything to do with this problem?

So, now, what do you guys suggest?
Should I take out the tranny and open up the front pump, bands, etc.?

Or could it be the Torque Converter?

Any guesses, advises.
BTW, I changed the fluid as well and pumped up air through all the cooler lines too. So there should be no problem there either.

Thanks in advance for your assistance.

Houman SS '70

RE: our PM's on this subject..... did you test reverse gear? Does it work when the forwards gears fail?

Have you run pressure tests when the trans fails to move correctly?
__________________
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
  #6 (permalink)  
Old 12-20-2005, 03:33 PM
Jeeps Are Us!
 

Last journal entry: The Paint Shop
Last photo:
Join Date: Jan 2005
Location: Tehran, Iran
Age: 39
Posts: 300
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Crosley,

Actually, I did try reverse, but I'm not sure, it seems to work better than D, L1 and L2, but maybe not.

I could not run pressure test, because here we don't have the equipment.

You know when I WOT and then let go, and then WOT there is a 2-3 second delay to react again! I don't know if you get what I'm saying.

I think there's something wrong with the convertor.

What do you comment?

My mechanic says that if there was any problem with tranny itself, I would definitly have some clutches toasted.

He also emphasises on Conv. so tomorrow we are going to open it up and see what's wrong.

Take care,
Houman
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 12-20-2005, 09:43 PM
fearsomefairmont's Avatar
Member
 
Join Date: Mar 2004
Location: wisconsin
Age: 30
Posts: 102
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Had a similar problem.....

Hi,
I had a similar problem with the turbo 400 in my '72.
The trans had around 2500 miles use (albeit HARD use, behind a 455 Olds) after a rebuild when it was parked for 6 years. When it was started and driven after sitting, it would barely move in D and only after it revved to around 3000 rpm, then it would drive alright till it sat idling in park for a little while. I suspected either slipping or or lack of fluid pressure.

When the trans was torn down for a rebuild, it ended up having the clutches and internals which looked great, but the seals had went bad after sitting and caused lack of proper fluid pressure. I thought the trans was slipping and torched but it turned out not to be the case.

Anyways, a rebuild would solve it.

Cheers,
Andy
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 12-22-2005, 03:33 PM
Jeeps Are Us!
 

Last journal entry: The Paint Shop
Last photo:
Join Date: Jan 2005
Location: Tehran, Iran
Age: 39
Posts: 300
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by fearsomefairmont
Hi,
I had a similar problem with the turbo 400 in my '72.
The trans had around 2500 miles use (albeit HARD use, behind a 455 Olds) after a rebuild when it was parked for 6 years. When it was started and driven after sitting, it would barely move in D and only after it revved to around 3000 rpm, then it would drive alright till it sat idling in park for a little while. I suspected either slipping or or lack of fluid pressure.

When the trans was torn down for a rebuild, it ended up having the clutches and internals which looked great, but the seals had went bad after sitting and caused lack of proper fluid pressure. I thought the trans was slipping and torched but it turned out not to be the case.

Anyways, a rebuild would solve it.

Cheers,
Andy

Hey Andy,

Thanks for your reply.

Today, I tore down the tranny.

The converter was o.k. and had no problem at all, and as I mentioned earlier, I had opened up the valve body and they were o.k. too.

So what was left? The clutches and the pump.

Guess what?
The first ring on the pump ( actually you can call it the first or the last depends where you start) the one at the tip of the pump shaft was broken!!!

I really don't know why, but anyway the pump shaft was also damaged, so I had to use another pump which I got out of a healthy tranny.

A couple of the clutches had changed color as well, but not really that much, so I replaced them as well and now the tranny is running fine again.
My tranny expert used teflon rings this time, he said at least the teflon rings if broken, they won't damage other things.
Do you have any comments about the teflon rings? Are they better???

I got a small problem and that is, the tranny does not shift as hard (firm) as it did before this damage.
What is it? I didn't get the time to tune the vacuum modulator screw, could it be that?

You know, my car would smoke when wot in 1st, but now it will not smoke, it will take off, but no smoke.

What do you suggest?

Thanks anyway for all the comments and assitance.

Best regards & Merry Xmass to all of you and your families.

Houman
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 12-22-2005, 06:42 PM
fearsomefairmont's Avatar
Member
 
Join Date: Mar 2004
Location: wisconsin
Age: 30
Posts: 102
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Some answers

Houman,
I don't really have any idea why you car would or would not smoke while at WOT, unless you just replaced the vacuum modulator. In this case you were most likely sucking tranny fluid out the ruptured diaphragm and this was causing the smoke.

About the teflon rings, I have heard they work well, but I have only built manual transmissions so I don't have any direct experience. I do have teflon rings in my TH-400, however, and no problems.

For shift quality, they are lot of variables which can affect this. If the trans was shifting hard prior to modulator replacement, it will shift less firmly than before once replaced. You could adjust it back to previous firmness as long as the range of adjustment is within the engine vacuum you have. If there is less vacuum vs. more, the shift quality will be harder.

It sounds like everything is under control. Makes me want to try my hand at building another th-400 as a spare for my ride. Any leads on a turbo-400 with a BOP bolt pattern.

If the car was sitting for awhile, and smoking under WOT, thrash it a little bit with a couple 0-80 WOT runs. After running it out like this it often cleans out crap from the engine. Plus, it is really fun.....

Happy Holidays,
Andy
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 12-22-2005, 11:04 PM
Jeeps Are Us!
 

Last journal entry: The Paint Shop
Last photo:
Join Date: Jan 2005
Location: Tehran, Iran
Age: 39
Posts: 300
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Hey Andy,

I think you misunderstood me.
I meant the tires would smoke. Not the exhaust!!!

But you know, last night I drove about a 100 miles, and now the tranny is more like it was before, and I like it this way.

I think today I'll try to adjust the vacuum modulator screw a little and see what happens.

You know, I always loved 400's, and thought they are much stronger and let's say more tough and rough than the 350, but this site Hotrodders, changed my mind.

I'll go with TH 350.
I don't have any strong reasoning behind my opinion, but check it out here and you'll see that TH 350 is more of a favorite than the 400.

Take care,
Houman
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 12-23-2005, 07:43 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: 8,060
Wiki Edits: 1659

Thanks: 316
Thanked 97 Times in 94 Posts
oh ........ I get it. Tire smoke.

A pressure check of this tranny would have shown a drop off of pressure when the car was placed into "D"..... this would point to the location of the troubles that were found when it was disassembled.

Glad to see it works well now , a happy ending
__________________
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
Distributor Tuning and Theory - Part 1 Rick WI Engine 35 04-26-2011 12:38 AM
Port or Full time vacuum cool rockin daddy Engine 129 10-05-2010 03:00 PM
Cam/Lifter Question about Ramjet 350 Jake Harsha Engine 20 07-07-2010 06:22 AM
348 or 350 delimma 62ImpalaSS Engine 12 05-17-2006 11:03 PM
350 Trans slipping please help :( Neil_UK Transmission - Rearend 11 09-12-2003 08:57 PM


All times are GMT -6. The time now is 04:41 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.