Author Topic: Original battery hold down bolt  (Read 18676 times)

Scott69Z

  • Newbie
  • *
  • Posts: 7
    • View Profile
Original battery hold down bolt
« on: June 01, 2013, 01:54:02 PM »
Could someone please help me by posting a picture of a correct battery hold down bolt. When I purchased my 69 Z28 it was missing the battery hold down and bolt. I purchased an original gm battery hold down and an amk under hood detailing kit which includes the battery hold down bolt. The bolt in the kit seems to be too short. I purchased a sealed R59 battery and I cannot seem to get this bolt to work. Thanks for the help.

lakeholme

  • Hero Member
  • *****
  • Posts: 2497
  • 68-12D L30/M35
    • View Profile
Re: Original battery hold down bolt
« Reply #1 on: June 01, 2013, 07:38:57 PM »
http://www.camaros.org/forum/index.php?topic=2899.0

Maybe JohnZ can re-post the pic. I couldn't get it to open.
Phillip, HNR & NCR-AACA, Senior Master, Team Captain, Admin.,
Spring Southeastern Nationals chair, AACA National Director

JohnZ

  • CRG Member
  • *****
  • Posts: 4365
    • View Profile
Re: Original battery hold down bolt
« Reply #2 on: June 02, 2013, 09:12:29 PM »
Here's the bolt on mine.
'69 Z/28
Fathom Green
CRG

Scott69Z

  • Newbie
  • *
  • Posts: 7
    • View Profile
Re: Original battery hold down bolt
« Reply #3 on: June 03, 2013, 12:24:43 AM »
Thanks for the pic. Does anyone know how long this bolt is suppose to be? Mine seems too short.

68camaroz28

  • Hero Member
  • *****
  • Posts: 2232
    • View Profile
Re: Original battery hold down bolt
« Reply #4 on: June 07, 2013, 11:45:48 AM »
http://www.camaros.net/forums/showthread.php?t=182584&highlight=3881339&page=35
Open up this team camaro link to our build thread and at the top of that page I have posted pics of original hold down clamps and a bolt. I have four original bolts (all in use) and they were all RBW with an oversize captured washer which makes it unique. Do not remember the length.
Chick
68 Z/28 NOR 01B Orig motor/trans/rear
69 Z/28 NOR 07A Orig Block & GM Cross-ram/carbs
69 L34 Rest. Nova Father/Son Car
69 L78 Surv Nova Purch 4/69 31K miles
67 L89 Corv Tribute
68 Corv 427/400 Orig motor
07 Corv Z06
R 68Z build- http://www.camaros.net/forums/showthread.php?t=182584

68camaroz28

  • Hero Member
  • *****
  • Posts: 2232
    • View Profile
Re: Original battery hold down bolt
« Reply #5 on: June 08, 2013, 12:46:33 AM »
http://www.camaros.net/forums/showthread.php?t=182584&highlight=3881339&page=35
Open up this team camaro link to our build thread and at the top of that page I have posted pics of original hold down clamps and a bolt. I have four original bolts (all in use) and they were all RBW with an oversize captured washer which makes it unique. Do not remember the length.
Update: I found one of my bolts to be a anchor supplied bolt. The large captured washer is approximately .85" in diameter and thread length is just under an inch.

Chick
68 Z/28 NOR 01B Orig motor/trans/rear
69 Z/28 NOR 07A Orig Block & GM Cross-ram/carbs
69 L34 Rest. Nova Father/Son Car
69 L78 Surv Nova Purch 4/69 31K miles
67 L89 Corv Tribute
68 Corv 427/400 Orig motor
07 Corv Z06
R 68Z build- http://www.camaros.net/forums/showthread.php?t=182584

big iron

  • Hero Member
  • *****
  • Posts: 685
    • View Profile
Re: Original battery hold down bolt
« Reply #6 on: November 05, 2014, 04:51:55 PM »
Seems to be two points of view here and in other threads I have looked at.
Let's look at the facts as presented in the AIM's
Same part number 3758783 and torque used in all three years of production for this particular bolt.
Why would the torque of 60-80 in lbs (6.6 ft lbs) be applied to this bolt when the same size bolts in the same area have 120-180 in lbs (12 ft lbs) applied to them.
I believe that the toothed conical washer was specified and thus the lower torque value.
If anyone has ever tried to change a battery in a first gen then you know why the lead point on the bolt was specified, especially with AC (67-68).
I bring these points of view, not to start an argument, but to reason why this particular bolt does not have an accepted specific style and measurement.
Thanks,
Bob

JohnZ

  • CRG Member
  • *****
  • Posts: 4365
    • View Profile
Re: Original battery hold down bolt
« Reply #7 on: November 05, 2014, 05:25:27 PM »

Same part number 3758783 and torque used in all three years of production for this particular bolt.
Why would the torque of 60-80 in lbs (6.6 ft lbs) be applied to this bolt when the same size bolts in the same area have 120-180 in lbs (12 ft lbs) applied to them.

On the battery hold-down application, the bolt is bearing down (through the clamp) on a molded tab that's part of the plastic battery case - a "soft make-up" application; too much torque, you break the case and have acid everywhere. Other applications using the same bolt join two steel parts, with "hard make-up" joints.
'69 Z/28
Fathom Green
CRG

big iron

  • Hero Member
  • *****
  • Posts: 685
    • View Profile
Re: Original battery hold down bolt
« Reply #8 on: November 05, 2014, 08:29:34 PM »

Same part number 3758783 and torque used in all three years of production for this particular bolt.
Why would the torque of 60-80 in lbs (6.6 ft lbs) be applied to this bolt when the same size bolts in the same area have 120-180 in lbs (12 ft lbs) applied to them.

On the battery hold-down application, the bolt is bearing down (through the clamp) on a molded tab that's part of the plastic battery case - a "soft make-up" application; too much torque, you break the case and have acid everywhere. Other applications using the same bolt join two steel parts, with "hard make-up" joints.
John,
How would the bolt stay tight at half of it's recommended torque?
Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?
Bob

JohnZ

  • CRG Member
  • *****
  • Posts: 4365
    • View Profile
Re: Original battery hold down bolt
« Reply #9 on: November 06, 2014, 02:39:04 PM »
John,
How would the bolt stay tight at half of it's recommended torque?
Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?
Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.
'69 Z/28
Fathom Green
CRG

big iron

  • Hero Member
  • *****
  • Posts: 685
    • View Profile
Re: Original battery hold down bolt
« Reply #10 on: November 06, 2014, 04:11:30 PM »
John,
How would the bolt stay tight at half of it's recommended torque?
Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?
Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.
In this case was the conical toothed washer used to maintain clamping force because of the soft joint? If not, why was toothed washer specified in this case?
Bob

68camaroz28

  • Hero Member
  • *****
  • Posts: 2232
    • View Profile
Re: Original battery hold down bolt
« Reply #11 on: November 07, 2014, 04:01:18 AM »
John,
How would the bolt stay tight at half of it's recommended torque?
Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?
Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.
In this case was the conical toothed washer used to maintain clamping force because of the soft joint? If not, why was toothed washer specified in this case?
Bob
Are you referring to the battery hold down bolt #3758783 Bob? It did not have a conical toothed washer that I'm aware of, just that oversize captured washer.
Chick
68 Z/28 NOR 01B Orig motor/trans/rear
69 Z/28 NOR 07A Orig Block & GM Cross-ram/carbs
69 L34 Rest. Nova Father/Son Car
69 L78 Surv Nova Purch 4/69 31K miles
67 L89 Corv Tribute
68 Corv 427/400 Orig motor
07 Corv Z06
R 68Z build- http://www.camaros.net/forums/showthread.php?t=182584

big iron

  • Hero Member
  • *****
  • Posts: 685
    • View Profile
Re: Original battery hold down bolt
« Reply #12 on: November 07, 2014, 06:52:49 AM »
Chick,
Yes.
The questions I have asked have arisen from reply #1 which indicates two types of bolts being used on survivors but only one type was factory specified.
Just trying to find an engineering answer to my reply #6 and now reply #10.
Bob

JohnZ

  • CRG Member
  • *****
  • Posts: 4365
    • View Profile
Re: Original battery hold down bolt
« Reply #13 on: November 07, 2014, 02:38:55 PM »
John,
How would the bolt stay tight at half of it's recommended torque?
Is the plastic case compressing and compensating for the lack of bolt stretch or are the teeth on the conical washer keeping the bolt tight?
Bob

"Recommended torque" on a fastener is determined by Fastener Engineering based on the type of joint and the joint materials involved; the fastener's job is to establish and maintain clamping force in the joint, and the torque required to do that is a function of the materials in the joint.
In this case was the conical toothed washer used to maintain clamping force because of the soft joint? If not, why was toothed washer specified in this case?
Bob

I guess you'd have to ask the responsible release engineer about the specifics.
'69 Z/28
Fathom Green
CRG

KurtS

  • CRG Coordinator
  • *****
  • Posts: 5884
    • View Profile
Re: Original battery hold down bolt
« Reply #14 on: November 07, 2014, 03:13:59 PM »
Clamping force required, that's all. They worked out the force required for the battery and generated the spec. Sure don't want to have the battery loose or crack the case.
Kurt S
CRG