Pontiac - Street No question too basic here!

          
Reply
 
Thread Tools Display Modes
  #1  
Old 04-27-2013, 07:18 AM
1967Tempest's Avatar
1967Tempest 1967Tempest is offline
Ultimate Warrior
 
Join Date: Jul 2006
Location: Fayetteville, GA
Posts: 3,020
Send a message via MSN to 1967Tempest
Default Throwout bearing length explaination needed

So this is the second 67 Tempest that I am swapping over to a manual.

Can someone please tell me WTF is up with the TO bearing? I mean, all transmissions that I would use Sag, Muncie, T10 would have the same measurements INSIDE the bell housing right?

So why no matter which clutch set I order, the TO bearing needs to be longer or an adjustable fork ball installed or both.

Does everyone here with a 67 manual need to order an additional TO bearing every time they order a clutch?

And this can ONLY be TO bearing length issue. Z bar throw and transmission dimensions cannot be changed, nor would it make a difference...

Thanks in advance..

Dave

__________________
1967 Pontiac Tempest 2dr HRDTP Coupe 468 C.I. 500 HP 5 speed = FUN!!!
1990 Chevy Suburban R2500 Daily Driver
1986 Volvo DL245 Wagon.. Project car!!!
The Burb Files
  #2  
Old 04-27-2013, 10:43 AM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Winchester, VA
Posts: 16,206
Default

I feel your pain! I think the problem is that the listings are wrong, or at least that's been my experience. What changes you ask, well, in some cases, the pressure plate, which can have a direct impact on the TO height.

Now it could be that the bellhousing is different than the listing/app is calling for.

Just as a reminder, the fork where the rod touches, should be 90 degrees to the centerline of the crank/driveline.

Or are you just venting!?! Heh-heh!

.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #3  
Old 04-27-2013, 01:26 PM
1967Tempest's Avatar
1967Tempest 1967Tempest is offline
Ultimate Warrior
 
Join Date: Jul 2006
Location: Fayetteville, GA
Posts: 3,020
Send a message via MSN to 1967Tempest
Default

Maybe a tad. But I have had 3 different TO bearings and I cant believe that they are all wrong for application..

New one should be here middle of next week.. I need to drive it soon. I am trying to get it road worth to make PY show in June!!!

__________________
1967 Pontiac Tempest 2dr HRDTP Coupe 468 C.I. 500 HP 5 speed = FUN!!!
1990 Chevy Suburban R2500 Daily Driver
1986 Volvo DL245 Wagon.. Project car!!!
The Burb Files
  #4  
Old 04-27-2013, 05:52 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,302
Default

If you have a pressure plate with many "Fingers", Typical diaphragm style, then you need a throw-out bearing with a rounded contact face/ outer edge.

If you have a pressure plate with a 3 "Fingers". Typical Borg & Beck style, then you need a throw-out bearing with a FLAT front surface/ and slightly rounded outer edge.

So now if you have that deal figured out then the next question is: Did you cut the factory cast iron flywheel? Did you install an aftermarket flywheel? A Lakewood scattershield?

If you have an aftermarket flywheel then the throw-out bearing might be in the wrong location vs the factory pivot ball location. Same deal if you installed the flat shield in front of the scatter shield.

So we need a lot more info about what you are actually doing.

Tom Vaught

__________________
"Engineers do stuff for reasons" Tom Vaught

Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.
  #5  
Old 04-27-2013, 10:35 PM
Grand73Am Grand73Am is offline
Ultimate Warrior
 
Join Date: Feb 2004
Location: Lawrenceville, GA
Posts: 2,953
Default

Some use long release bearings, and some use short ones. The type of pressure plate you are using does make a difference. The diaphragm type is the stock type of setup, with the many flat fingers which are relatively flat to the pressure plate housing, so it uses the long bearing. The "performance" 3 finger type have fingers that are more raised outside the housing, so use a shorter bearing. So, if you have diaphragm type of pressure plate and it won't release, you obviously need the long bearing. There's even an adjustable length release bearing available for odd situations.

__________________
Steve F.
  #6  
Old 04-28-2013, 07:00 AM
1967Tempest's Avatar
1967Tempest 1967Tempest is offline
Ultimate Warrior
 
Join Date: Jul 2006
Location: Fayetteville, GA
Posts: 3,020
Send a message via MSN to 1967Tempest
Default

I have an aftermarket OEM style flywheel with a Pontiac bell housing with a stock style z bar set-up. The engine mounts are in the correct loaction (factory) I welded the z bar bracket dead nuts to where the z bar is on a good perpendicular angle. No sway or engine rocking.

I have the HD style clutch rod. Although it was too long and needed some messaging on the grinder. Works great now.

Stock-ish set-up and I got no separation from flywheel and disc.

Readjusted clutch rod for ZERO gap to see if that would make any difference. I got a little marcal movement, but not and separation.

I have a diaphragm style clutch with the TO bearing that it came with.

Same thing happened on last Tempest. I ordered National PN# 1377C. Should be here in a few. Ill swap it out then.

I'm just curious as to why all of these short bearings don't move the PP away. I mean if you JUST changed a clutch in a 67 from original you would run into this issue wouldn't you???

The TO bearing on left came with clutch. 1377 in the middle..
Attached Thumbnails
Click image for larger version

Name:	DSCF2234.jpg
Views:	537
Size:	99.3 KB
ID:	321413  

__________________
1967 Pontiac Tempest 2dr HRDTP Coupe 468 C.I. 500 HP 5 speed = FUN!!!
1990 Chevy Suburban R2500 Daily Driver
1986 Volvo DL245 Wagon.. Project car!!!
The Burb Files
  #7  
Old 04-28-2013, 09:44 AM
Grand73Am Grand73Am is offline
Ultimate Warrior
 
Join Date: Feb 2004
Location: Lawrenceville, GA
Posts: 2,953
Default

I was putting a clutch in a 57 Chevy for a customer. He had bought the parts from Summit, which included a scattershield, flywheel, clutch, diaphragm pressure plate and short release bearing. The 57 was set up with original clutch linkage. I knew a 57 uses a long bearing. I told him the short bearing wasn't going to work. He said it's all supposed to work together, so I didn't argue and put it in and of course, it didn't work. So, he had to pay me to take it back apart and put in a long bearing which is now working. I don't know why the parts places are putting short bearings in with these clutch kits. I don't see how it can work without different geometry in the clutch fork and linkage.

__________________
Steve F.
  #8  
Old 04-28-2013, 03:18 PM
1967Tempest's Avatar
1967Tempest 1967Tempest is offline
Ultimate Warrior
 
Join Date: Jul 2006
Location: Fayetteville, GA
Posts: 3,020
Send a message via MSN to 1967Tempest
Default

Quote:
Originally Posted by Grand73Am View Post
I was putting a clutch in a 57 Chevy for a customer. He had bought the parts from Summit, which included a scattershield, flywheel, clutch, diaphragm pressure plate and short release bearing. The 57 was set up with original clutch linkage. I knew a 57 uses a long bearing. I told him the short bearing wasn't going to work. He said it's all supposed to work together, so I didn't argue and put it in and of course, it didn't work. So, he had to pay me to take it back apart and put in a long bearing which is now working. I don't know why the parts places are putting short bearings in with these clutch kits. I don't see how it can work without different geometry in the clutch fork and linkage.

Maybe that is my point. I think the longer bearings are needed..

__________________
1967 Pontiac Tempest 2dr HRDTP Coupe 468 C.I. 500 HP 5 speed = FUN!!!
1990 Chevy Suburban R2500 Daily Driver
1986 Volvo DL245 Wagon.. Project car!!!
The Burb Files
Reply


Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -4. The time now is 12:01 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017