Repro Diff Cover to Leaf Spring Bolts Too Long

[Jack O.]

I got some repro leaf spring bolts from paragon that are too long and bottom out in the front of the diff holes. They are 3 and 9/16" while my originals that I removed are 3 and 1/4". I noticed that paragon sells two different sets - one for 7 leaf and one for 9 leaf and I did get the 9 leaf ones which should be correct for my car. The ones I removed I believe are original as they have a WB on them. Has anyone else had this issue or know the correct length these botls should be?
Thanks,
Jack

[Jim D.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

The ones I got from Paragon were too long as well. I had to cut them to match the length of the original ones.

[Harry S.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

This has been an ongoing problem with the parts suppliers. The bolts they send are too long. As I recall the parts suppliers sell two lengths of bolts and the set for the F41 spring is shorter, that is the bolt set you need. There has been several threads on this in the past. Please search the archives.

[Jack O.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

Thanks, I'll check the archives. I just got off the phone with paragon and I'm being told "they've been selling them for yeaars with no issue" and "they use them all the time at their shop on restorations". The ones they sell for a 7 leaf spring are the same length as what came out, ~3 5/16", so I ordered tehose.

[Peter H.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

Hi jack i ordered the bolts for the 7 leaf springs and received bolt the were considerably longer .. Their answer was you must have ordered the wrong ones !!!!!!! I made a special 4 hour trip to exchange the bolts for shorter ones but still had to shorten them to match my original one .... Not too impresed ..

[Jack O.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

The guy on the phone supposedly measured the shorter ones and came up with 3 5/16" - I'lll be even more unhappy if they're still wrong and will be ready to simply reuse my old ones!

[Peter H.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

thanks, i'll check the archives. I just got off the phone with paragon and i'm being told "they've been selling them for yeaars with no issue" and "they use them all the time at their shop on restorations". The ones they sell for a 7 leaf spring are the same length as what came out, ~3 5/16", so i ordered tehose.

they must be selling a lot of differentials covers also.... The know they have a big problem . Will not be calling them again.

[Alan D.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

That is bolt 3833486 in Gr 7.529 specified as 9/16 - 12 X 3 1/8" You can also find the pn in the AIM Sec 4 sheet B1.00
I find only one bolt.
Now sometimes when we try to help these repro vendors they act like corvette nuts, oh well

[Joe L.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

All---


The GM spec for the 3833486 bolt calls for it to be 3-7/32" shank length. Its later SERVICE replacement bolt, GM #9428598 was supposed to be 3-3/4" shank length with a 1-3/8" thread length. I don't know how the longer bolt would have worked but GM did catalog it as the replacement for the 3833486.

According to GM, ALL 1963-74 Corvettes originally used the 3833486 bolt whether equipped with standard or F-40/41 suspension.

[Anthony P.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

AS i REMEMBER!! In the late 60s early 70s I worked as a young mechanic (in training) at a local Detroit shop that catered to muscle cars, my memory of these bolts we that on the 9 leaf springs the bolts were actually two different sizes, 2 short about 3 inchs long and 2 longer about 3 1/2 inchs long. Can anyone colaborate this and validate an old mans memory?

[Joe L.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

AS i REMEMBER!! In the late 60s early 70s I worked as a young mechanic (in training) at a local Detroit shop that catered to muscle cars, my memory of these bolts we that on the 9 leaf springs the bolts were actually two different sizes, 2 short about 3 inchs long and 2 longer about 3 1/2 inchs long. Can anyone colaborate this and validate an old mans memory?

Tony------


I can't. The original bolts on my 1969 with 9 leaf spring were all the same length. GM says that the same bolt was used for all 1963-74 Corvettes regardless of suspension option or any other factor.

[Wayne M.]

Re: Repro Diff Cover to Leaf Spring Bolts Too Long

Red flags should go up if the thread count is any different than shown in pic below of originals from a '64 or '65 9-leaf spring. Also note the thickness of the lock washers.



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