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10" bolts for rear spring ...

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Old 05-14-2017, 11:27 AM
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69Chevelle
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Default 10" bolts for rear spring ...

I know I've seen it in the forum but I sure can't find it. Where can I buy 10" bolts for my 71's rear spring ?
Old 05-14-2017, 11:49 AM
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gbvette62
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You have to look in an 84-96 catalog, they're not sold for 68-82's.
Old 05-14-2017, 12:22 PM
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mikem350
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I would search the forum for the bad things that can happen using those length bolts!!

Like they can hit the tire rim, hit the pavement in event of tire failure....

Best to figure out (and fix) why it sits so high!!!
Old 05-14-2017, 12:28 PM
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Alan 71
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Hi 69,
I agree with m350.
The longer bolt is a solution... but doesn't address the actual cause of the problem.
In fact, as he describes, it can cause it's own problems.
Have you made some changes to the rear suspension that have resulted in the need for a bolt that is that long?
Regards,
Alan
Old 05-14-2017, 01:16 PM
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69Chevelle
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I put a new rear mono spring in, replaced the U joints, KYB gas shocks as well as 17" rims and tires. The tire height is 27" but the wheel opening looks to be about 2" too high.




Old 05-14-2017, 02:06 PM
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Alan 71
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Hi 69 C,
27" is very close to the height of the original wheel/tire used on your 71.
The original dimension from the ground to the center of the wheel arch was just a hair below 28" with the 27" wheel/tire combination.
If that dimension is greater than that on your car, it's the result of the specifications/rating of the spring you chose.
The longer bolt is really the only option at this point.
Regards,
Alan

Last edited by Alan 71; 05-14-2017 at 02:06 PM.
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Old 05-14-2017, 05:11 PM
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ignatz
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69: Do you have spacers between the spring and differential? If so you can swap those top to bottom to lower things a bit. You need to be pretty careful with longer bolts that you don't create interference under load somewhere you don't want it.
Old 05-14-2017, 05:58 PM
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69Chevelle
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Default 10" bolts

Originally Posted by ignatz
69: Do you have spacers between the spring and differential? If so you can swap those top to bottom to lower things a bit. You need to be pretty careful with longer bolts that you don't create interference under load somewhere you don't want it.
I'll check that tomorrow night when I can get it up on a lift. As I recall they come with a series of spacers which were taped together. So if I remove one or two off the top that should bring the back down ?

Is there any other things I should be aware of if I remove the spacers ?
Old 05-14-2017, 06:01 PM
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ignatz
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Originally Posted by 69Chevelle
Is there any other things I should be aware of if I remove the spacers ?
Yup - don't bottom out the bolts! Just exchange the spacers.
Old 05-14-2017, 07:29 PM
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Gale Banks 80'
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I found it strange that the local Bolt suppliers couldn't get 10" Bolts. VB&P has them. Your car doesn't look all that high to me. Once You have the car at the height you want you can always cut off the extra threads on the bolts.
Old 05-14-2017, 07:38 PM
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69Chevelle
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Originally Posted by Alan 71
Hi 69 C,
27" is very close to the height of the original wheel/tire used on your 71.
The original dimension from the ground to the center of the wheel arch was just a hair below 28" with the 27" wheel/tire combination.
If that dimension is greater than that on your car, it's the result of the specifications/rating of the spring you chose.
The longer bolt is really the only option at this point.
Regards,
Alan
Checked my wheel arch height and it's 29-3/8" so according to your stats I'm an 1-3/8" high.
Old 05-14-2017, 07:40 PM
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kansas123
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Originally Posted by ignatz
69: Do you have spacers between the spring and differential? If so you can swap those top to bottom to lower things a bit. You need to be pretty careful with longer bolts that you don't create interference under load somewhere you don't want it.
Hot Dog! I never thought about doing this! After I put on rebuilt trailing arms, new shocks, half shafts, and strut rods, I was sitting about an inch too high. I already have 8 " bolts and didn't want to go any longer, and was just going to live with how it looked. Now you have furnished another solution! Yea! Many thanks!
Old 05-14-2017, 10:09 PM
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ignatz
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Found a photo of my setup. Looks to be about an inch of stuff under the spring.



This brings up another point, some heat shielding from the exhaust as a precautionary measure. My spring is easily 20+ years old and doing fine.

My memory seems to have been wrong about the bolts bottoming out. These look to be through holes. Still without proper spacing, you could run out of thread.
Old 05-15-2017, 08:39 AM
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resdoggie
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On my diff, the aft spring bolt holes go through. The two forward holes don't.
Old 05-15-2017, 09:20 AM
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Originally Posted by resdoggie
On my diff, the aft spring bolt holes go through. The two forward holes don't.
Old 05-15-2017, 02:36 PM
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A local Ring Power or Caterpillar dealer is a good source for longer and larger grade 8 bolts.
Old 05-15-2017, 02:47 PM
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When you torque those four bolts back down make sure it's done with the weight of the car on the spring or you can crack the ears off the diff.

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Old 05-15-2017, 02:59 PM
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Kinda glad I asked the question now. Lots of good info came out of this and appears to help more than just me. Sure do appreciate all the expert help you get on this site. I won't have my car on the lift until Wednesday now but will post pictures of the spring spacers before and after as well as measuring the height change.
Old 05-15-2017, 05:14 PM
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he used the TRW spring... and that is the problem...

Also... FYI,,, The KYB shocks will NOT be able to handle the responsiveness of the fiberglass spring, thus you will have wheel hop ....

my advise... ditch the TRW, and get a correct spring for hight, and ditch the KYB's and get some good Bilstin SPORT shocks... all problems solved.


And no, any other fix regardless of what you are told is nothing short of a bandaid fix.

Last edited by pauldana; 05-15-2017 at 05:15 PM.
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Old 05-15-2017, 05:51 PM
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Originally Posted by pauldana
he used the TRW spring... and that is the problem...

Also... FYI,,, The KYB shocks will NOT be able to handle the responsiveness of the fiberglass spring, thus you will have wheel hop ....

my advise... ditch the TRW, and get a correct spring for hight, and ditch the KYB's and get some good Bilstin SPORT shocks... all problems solved.


And no, any other fix regardless of what you are told is nothing short of a bandaid fix.
I have to agree with you about the TRW spring if that is what the picture of the end plates is telling you. However I remember the ends as being rounded and kind of fat, though that was long ago. Anyway I had one and tossed it as well. Even so I still had to arrange my shims as shown to get to my desired ride height.

Last edited by ignatz; 05-15-2017 at 05:52 PM.


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