Rear spring bolts
Thread Starter
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
Rear spring bolts
Yesterday I purchased 2 grade 8 8" rear spring bolts with locknuts from a local industrial fastener biz for $5.50. Sure beats the vette supplier's price of ~ $20. Anyone who wants to lower their rear (their vette's rear, that is), check locally first.
Brett :thumbs:
Brett :thumbs:
Team Owner
Joined: Feb 1999
Posts: 34,454
Likes: 665
From: Republic of Texas
Re: Rear spring bolts (Brettmc)
I ordered the set and installed them last weekend. It dropped the car a whole 1/2 inch. :rolleyes: I don't know if this is due to my rear fiberglass spring or not. I did as you did and found some longer bolts locally for about $6.
:cheers:
:cheers:
Race Director
Joined: Jul 2002
Posts: 10,154
Likes: 20
From: Texas
Re: Rear spring bolts (Corey 68)
Corey-
how long were the bolts you installed? I have the same problem with the fiberglass spring on my '69. The rear of my car sits about 2 1/2" too high (my sig pic was taken before the new spring). The longer bolts from the 'vette parts suppliers only appear to be 8" long. I don't want to switch them out if it's only going to drop a 1/2".
how long were the bolts you installed? I have the same problem with the fiberglass spring on my '69. The rear of my car sits about 2 1/2" too high (my sig pic was taken before the new spring). The longer bolts from the 'vette parts suppliers only appear to be 8" long. I don't want to switch them out if it's only going to drop a 1/2".
Team Owner
Joined: Feb 1999
Posts: 34,454
Likes: 665
From: Republic of Texas
Re: Rear spring bolts (Jeff 6T9)
Jeff, I'm going to the shop in a little bit and I'll take some measurements for you of the bolts and with the new bolts installed. I picked up the longer bolts today and I'll take pics of the bolts after for you. I do believe the Vette Brakes bolts are 8" long.
:cheers:
:cheers:
Team Owner
Joined: Feb 1999
Posts: 34,454
Likes: 665
From: Republic of Texas
Re: Rear spring bolts (Corey 68)
Jeff,
Just came back from the shop.
Here is how the car sits with the Vette Brakes rear lowering bots and fiberglass rear spring.
It sits at 30 3/4.
Here are the bolts.
The galvanized bolt, the gold Vette Brakes bolt and black stock bolt. I'm going to have to shave the new bolt to fit through the hole.
Just came back from the shop.
Here is how the car sits with the Vette Brakes rear lowering bots and fiberglass rear spring.
It sits at 30 3/4.
Here are the bolts.
The galvanized bolt, the gold Vette Brakes bolt and black stock bolt. I'm going to have to shave the new bolt to fit through the hole.
Le Mans Master
Joined: Oct 2001
Posts: 5,943
Likes: 3
From: Wildwood IL
Re: Rear spring bolts (Corey 68)
Corey: Is that galvanized carriage bolt in the pic the one your going to use on the rear spring?? DO NOT use it unless it's a grade 8. (I've never seen a grade 8 carriage bolt)
Eddie
Here are the bolts.
The galvanized bolt, the gold Vette Brakes bolt and black stock bolt. I'm going to have to shave the new bolt to fit through the hole.
[/QUOTE]
Eddie
Here are the bolts.
The galvanized bolt, the gold Vette Brakes bolt and black stock bolt. I'm going to have to shave the new bolt to fit through the hole.
[/QUOTE]
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Team Owner
Joined: Feb 1999
Posts: 34,454
Likes: 665
From: Republic of Texas
Re: Rear spring bolts (Silvr77)
Corey: Is that galvanized carriage bolt in the pic the one your going to use on the rear spring?? DO NOT use it unless it's a grade 8. (I've never seen a grade 8 carriage bolt)
Eddie
Eddie
[Modified by Corey 68, 10:24 PM 5/2/2003]
Racer
Joined: Sep 2000
Posts: 262
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From: Richmond, VA.
Re: Rear spring bolts (Corey 68)
Corey,
I had the same problem after I added a fiberglass spring. I used the lowering bolt from Vette Brakes, but it wasn't enough. I went to the local fastener shop and purchased grade 8 all-thread and six grade 8 nuts. I spot welded one nut to the top and used the other two as locking nuts for the bottom. Less than $10 for all. I needed 10 1/2 inches for mine to sit right. Works just fine.
If you go to the Vette Brakes web site, or cataloge, look for the C4 lowering bolts. They are the perfect lenth for a C3 with a fiberglass spring. The part number is 32309 @ $39.95 I am sure locally purchased bolts would be cheaper.
Good Luck, Steve.
I had the same problem after I added a fiberglass spring. I used the lowering bolt from Vette Brakes, but it wasn't enough. I went to the local fastener shop and purchased grade 8 all-thread and six grade 8 nuts. I spot welded one nut to the top and used the other two as locking nuts for the bottom. Less than $10 for all. I needed 10 1/2 inches for mine to sit right. Works just fine.
If you go to the Vette Brakes web site, or cataloge, look for the C4 lowering bolts. They are the perfect lenth for a C3 with a fiberglass spring. The part number is 32309 @ $39.95 I am sure locally purchased bolts would be cheaper.
Good Luck, Steve.
Le Mans Master
Joined: Oct 2001
Posts: 5,943
Likes: 3
From: Wildwood IL
Re: Rear spring bolts (Corey 68)
Eddie, not this is not the bolt I will be going with, I realized after I left it wasn't Grade 8. I will probably use an "all thread" and weld a nut on top so in reality I can lower the car as much as I want. I agree, use nothing less than Grade 8 for strength. :thumbs:
Eddie
Race Director
Joined: Jul 2002
Posts: 10,154
Likes: 20
From: Texas
Re: Rear spring bolts (Corey 68)
Corey -
thanks for the info. For some reason I can't see the pics, though.
Let me know how much length you end up needing to get the car where it needs to be. Also, didn't you have some issues with the coils up front, too? I need to replace mine, and I don't want to have the nose high once I get the rear down.
thanks for the info. For some reason I can't see the pics, though.
Let me know how much length you end up needing to get the car where it needs to be. Also, didn't you have some issues with the coils up front, too? I need to replace mine, and I don't want to have the nose high once I get the rear down.
Team Owner
Joined: Feb 1999
Posts: 34,454
Likes: 665
From: Republic of Texas
Re: Rear spring bolts (Jeff 6T9)
Jeff 6T9
Well, I put the VB bolts back in and going to wait and see how she sits with the battery, convertible top, bumpers and interior. I think with all of that it will drop another 3/4-1in. Same goes for the front, I have yet to add :hood, carb, PB,MC, bumpers, oil, water in the rad. If it doesn't come down any more I will cut 1/4 of a coil off the #550 springs.
I keep you posted :thumbs:
Well, I put the VB bolts back in and going to wait and see how she sits with the battery, convertible top, bumpers and interior. I think with all of that it will drop another 3/4-1in. Same goes for the front, I have yet to add :hood, carb, PB,MC, bumpers, oil, water in the rad. If it doesn't come down any more I will cut 1/4 of a coil off the #550 springs.
I keep you posted :thumbs:
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Rear spring bolts (Brettmc)
What size did you buy. I have used the 1/2 inch before grade 10 or 12 and it broke driving down the highway.
I went back to my old mild steel bolts for a while then switched once again to 9/16 x 8 inch grade 10 bolt with locking nuts.
I feel the lock nuts will not loosen but still visually check them occasionally.
I went back to my old mild steel bolts for a while then switched once again to 9/16 x 8 inch grade 10 bolt with locking nuts.
I feel the lock nuts will not loosen but still visually check them occasionally.
Le Mans Master
Joined: Oct 2001
Posts: 5,145
Likes: 125
From: The Motor City
Re: Rear spring bolts (norvalwilhelm)
Guys with 10" bolts and a composite spring:
Can you all check and see how close the end of your spring is to your tire and let me know?
Mine right now is 3/8" from the sidewall and rubs the tire on hard corners. My rear tires are 255 wide but I'm not sure of the backspace on these wheels. Right now my options for fixing this issue is either to go back to the 8" bolt and deal with the higher ride height or find new wheels with different backspace/offset. (My spring has a slight arch, even without a spare tire or tub weighing the back down.)
Can you all check and see how close the end of your spring is to your tire and let me know?
Mine right now is 3/8" from the sidewall and rubs the tire on hard corners. My rear tires are 255 wide but I'm not sure of the backspace on these wheels. Right now my options for fixing this issue is either to go back to the 8" bolt and deal with the higher ride height or find new wheels with different backspace/offset. (My spring has a slight arch, even without a spare tire or tub weighing the back down.)
Le Mans Master
Joined: Oct 2001
Posts: 5,943
Likes: 3
From: Wildwood IL
Re: Rear spring bolts (norvalwilhelm)
I feel the lock nuts will not loosen but still visually check them occasionally.
Eddie
Melting Slicks
Joined: Jul 2002
Posts: 3,000
Likes: 22
From: Boulder Creek California
Re: Rear spring bolts (Silvr77)
Is there an approximate ratio between how far you move the nut down the bolt and how much the car lowers? Obviously not one to one, or you guys with 10 inchers would be on the ground!
-Chris
[Modified by RUXperienced, 4:02 PM 5/6/2003]
-Chris
[Modified by RUXperienced, 4:02 PM 5/6/2003]
