Question on t******* the new leaf spring bolt

[Michael L.]

leaf spring bolt.jpg

Guys,

I restored the leaf spring on my 69 and have a question on the length of the leaf spring bolt. It seems awfully long. Should I cut it down?

Mike

[Harry S.]

Re: Question on t******* the new leaf spring bolt

Yes, as soon as you have it at proper torque cut it as sloppy as you can. This will stop the nut from backing off. Don't cut it too close to the nut. Also give the cut end a good smack with a 5 LB sledge. Not interested in pretty here, we're after safety.

[Gary B.]

Re: Question on t******* the new leaf spring bolt

Mike,

Also make sure the head is not too tall. Some repro center bolts have a too tall head.

Gary

[Michael L.]

Re: Question on t******* the new leaf spring bolt

thanks guys. Is there a height on the head I should shoot for?

Mike

[Michael L.]

Re: Question on t******* the new leaf spring bolt

Also, what is the torque spec for the leaf bolt? I'm guessing its not in the AIM since they probably came to the factory pre-assembled.

Mike

[Richard M.]

Re: Question on t******* the new leaf spring bolt

Mike, Best to use 2 C-Clamps to compress each side of the leaves before you snug up the bolt. IIRC it's a 5/16" UNF so 12-15 lbs/ft should be good.

Yes definitely check bolt top head height. Last few I've done had to be ground down before use. If you don't it binds in the carrier case and could even possibly damage it, as well as not laying up in there flat.

Some additional info in This Post.

Rich

[Tim G.]

Re: Question on t******* the new leaf spring bolt

We did a spring on a '67 Saturday. Don't forget to do the final torque with the wheels on the ground and the spring as horizontal as possible. We've replaced two differential covers where one flange broke off from not torqueing properly.

[Gary B.]

Re: Question on t******* the new leaf spring bolt

thanks guys. Is there a height on the head I should shoot for?

Mike

Mike I think the head on some of the repro bolts was about 2 times as tall as what the originals were.

Gary

[Joe L.]

Re: Question on t******* the new leaf spring bolt

Mike I think the head on some of the repro bolts was about 2 times as tall as what the originals were.

Gary

Gary------


Not just repro bolts. The GM SERVICE bolts had too tall heads for many years.

[Gary B.]

Re: Question on t******* the new leaf spring bolt

Joe,

Thanks for the correction. Hard to expect the repro companies to get it right if GM gets it wrong.

Gary

[Richard M.]

Re: Question on t******* the new leaf spring bolt

We did a spring on a '67 Saturday. Don't forget to do the final torque with the wheels on the ground and the spring as horizontal as possible. We've replaced two differential covers where one flange broke off from not torqueing properly.

Yes Tim's info is very important. It's a good idea to also measure your overall spring thickness and bolts to make sure they don't bottom out. I had a recent awakening after restoring a spring and discovered the new liners were not as thick as originals and the bolts bottomed out.

Just another FYI with Bolt info Here

[Joe L.]

Re: Question on t******* the new leaf spring bolt

Joe,

Thanks for the correction. Hard to expect the repro companies to get it right if GM gets it wrong.

Gary

Gary------


Here's what the GM bolts look like. The bolt head is at least twice as high as it needs to be for a 1963-79 Corvette.


springcenterbolts.jpg

[Wayne M.]

Re: Question on t******* the new leaf spring bolt

Here's the original off my (standard suspension) '65. Bolt is 3.0" overall length; head is 1/2" dia, and 1/4" high. Looks like a "W" headmark.

65 spring bolt.JPG

[R N.]

Re: Question on t******* the new leaf spring bolt

Mike I think the head on some of the repro bolts was about 2 times as tall as what the originals were.

Gary

Attached are some photos of an original bolt (Rusted) along side the current reproduction part (Sourced Paragon & CC)
IMG_6210.jpgIMG_6211.jpg

[Lawrence M.]

Re: Question on t******* the new leaf spring bolt

Also, what is the torque spec for the leaf bolt? I'm guessing its not in the AIM since they probably came to the factory pre-assembled.

Mike

I've never found a torque spec for that bolt. I believe the reason the threads are usually found mashed or staked was to prevent the nut from coming loose.