Rear Spring Hanger bolts

[Bill75]

Could someone tell me the thread size and length of the longer bolts to lower the rear end, I think they're 8 1/2 inches long.

I ordered some from Ecklers last week, "In stock" they said. They were back ordered on the packing list I just recd. with some other stuff that said 'usually ships withen 3-5 days". I just called them and they said June 16th!!!!!!!! What a bunch of clowns I hate um! ad

I'm going to see if I can get some at a specialty hardware shop.

Thanks

 

[GTR1999]

Bill,

9/16-18 x 8" grade 8 with nylock nuts. Let me know if you find them locally. I bought a set from Dana a few years for $20. I oculdn;t find a local source though. I just got in a new spring htat is supposed to be arched correctly and not need the long bolts- I hope so because I don't like the 8" bolts all that much.

 

[Bill75]

Bolts

Hi Gary,

Great, thanks for the reply. This darn rearend sits way too high for me, it has a replacement spring in it, I think is says JRS or something on it.
I'll make a few calls this afternoon and see how I make out.

Nice to hear from you, did you do the rearend over for that guy I met at your place?

Bill

 

[JohnZ]

Replacement springs with "JRS" stenciled on them are made by John R. Spring Service in Warren, Michigan, and generally result in excessive ride height. The best replacement rear springs are made by Eaton Detroit Spring (www.eatonsprings.com) in Detroit; they are usually very close to the original ride height after installation and about 50-100 miles of driving.

 

[GTR1999]

Hi Bill,
No, he sent it out for a general rebuild. That's ok I just wanted to give him another option for a blueprinted differential.

I have a couple of replacement rear springs and everyone needed the 8" bolts. The car ride was ok, but would have liked to use the 6.25 bolts with castle nut and cotter pins. I just got in a Spring from Bairs and it's supposed to fit with the stock bolts and give correct ride height. It's a single arch spring, doesn't have the straight short leafs in it. John would this be an Eaton spring?? Would the full arch have any effect on the car other then not appearing stock?

One thing I found rebuilding the last few rear ends was the HD rear cover from Muskegon have a little tighter bolt pattern to them. The center - center bolt pattern was tight enough the replacement spring required a slight bevel to clear the 4 mounting bolts. This didn't affect the security of the spring and it wasn't the spring that was the problem- it fit a stock rear cover fine.

Gary

 

[Bill75]

Thanks John, someone installed that spring just before I bought the car, the paint was still real fresh on it. You're right about the ride height, I don't like it at all, the car rides OK but I don't like the looks of it. I almost changed it when I had the rearend out this past winter and now I wish I had. Thanks for the link to Eaton I'll look into it for next winters project.

OK on everythig Gary, I hope your spring works out, seems there's alot of talk about getting longer bolts after somebody changes springs. The must have lost the formula for rear spring manufacturing!!

Take care guys and thanks.

Bill

 

[Bill75]

Interesting article about mono springs on Eatons web page

 

[JohnZ]

I have a couple of replacement rear springs and everyone needed the 8" bolts. The car ride was ok, but would have liked to use the 6.25 bolts with castle nut and cotter pins. I just got in a Spring from Bairs and it's supposed to fit with the stock bolts and give correct ride height. It's a single arch spring, doesn't have the straight short leafs in it. John would this be an Eaton spring?? Would the full arch have any effect on the car other then not appearing stock? Gary

How many leaves in the replacement from Bair's? The only 7-leaf all-curved spring used in production was the F41 rear spring (which was only optional on C2 fuelies and solid-lifter big-blocks and on some later C3's), which gave the same ride height as the standard 9-leaf spring, but had twice the load rate and a lot of ride harshness as a result. The only 9-leaf all-curved spring used in production was on 63's, and it was a one-year-only part; from '64-up through '76 or so, all Corvettes used the same 9-leaf spring with three flat top leaves and six curved lower leaves.

Our local shop says the John R. 7-leaf spring generally gives correct ride height with stock-length link bolts, but few customers like the hard ride. I have an Eaton-Detroit reproduction (correct) 9-leaf spring on my '67, and it's right on the money for both ride quality and ride height.

 

[fl_rider]

I can go off road now..

I just installed a Mid America 9 leaf 2-1/2 inch spring in my 78.
It rides much nicer but the altitude is getting to me. I should have ordered the 8 inch bolts. DOH

 

[GTR1999]

John, it has 9 leafs in it and they're all curved. I asked Brian Bair about this yesterday and he said they use them all the time and work fine with the stock bolts. I've dealt with Brain for years now and certainly trust him to offer quality parts. He has a USA source for them too which is nice to know.
I haven't installed it yet but I did lay it on top of the 9 leaf CC spring I have and the arch is much more curved then the CC spring.Also it doesn't have the typical clips on the leafs either. I don't care how it looks as long as it performs as good as stock.

 

[JohnZ]

If it provides the correct ride height, that's what you're after, and you'll be happy with it; correct appearance only matters for judging. I wouldn't be concerned about different arch height with the spring unloaded - that doesn't mean much; spring deflection is specified and measured at design load height, not free height.

 

[GerryLP]

Could someone tell me the thread size and length of the longer bolts to lower the rear end, I think they're 8 1/2 inches long.

I ordered some from Ecklers last week, "In stock" they said. They were back ordered on the packing list I just recd. with some other stuff that said 'usually ships withen 3-5 days". I just called them and they said June 16th!!!!!!!! What a bunch of clowns I hate um! ad

I'm going to see if I can get some at a specialty hardware shop.

Thanks

If you can, consider ordering them from another vendor, and then return the "late June" ones. Nowadays, there are plenty of supliers to accomodate your demands.

GerryLP:cool

 

[Bill75]

If you can, consider ordering them from another vendor, and then return the "late June" ones. Nowadays, there are plenty of supliers to accomodate your demands.

GerryLP:cool

You got that right! I was unable to get anything locally from a hardware specialty shop this weekend, I thought they'd have them and I'd do just what you said. More looking around tomorrow.

 

[WayneLBurnham]

I got mine from a simple Ace Hardware....

Had one break that was on the car. From what JohnZ said at the time, those were not factory (they were maybe 3/8ths and marked grade 5.) I switched to the VBP Dual Mount mono spring - I was paranoid enough about another spring breaking I went with either 9/16ths or 5/8ths Grade 8 NF with Grade 8 nylocks. I don't remember which one I ended up using, but I got a variety of 1/2 - 5/8ths from 6-10". The ones I used required me to very slightly enlarge the hole where the hanger goes to on the wheel side (not on the spring!)

They ran all of $1.50-2.50 each, and another few bucks for some thick grade 8 washers and the grade 8 nylocks (not really needed - bolts break far more easily than nuts.) Castle nuts and cotter pins are good also, but when altering lengths, you may have to add washers or additional nuts to get the right spacing. I prefer nylocks anywhere where extreme heat is not encountered - but remember, if you use them excessively they need replacing as the nylon insert takes a "set" and stops clamping as well. (On a large diameter bolt like that, that's a fair number of adjustments before that usually happens.)

Some really long head bolts may also be a good size, although the length is a problem. If you have an industrial nut and bolt supplier in the area with an "indoor sales" section, you might be able to get what you're looking for tomorrow. You could also try an automotive bolt supplier like ARP fasteners if normal vette channels are proving tough.

 

[Bill75]

Hello Wayne,
Thanks for all the good information, I'll check them out tomorrow. There's some industrial fastener places around here, seems as though they should have something.

Bill

 

[GTR1999]

Bill.,
If you find them locally, let me know where. No one down here stocked them.

 

[Bill75]

Nobody up here either. I can buy 100 pcs for about $500 from a supplier but not having any luck otherwise. VBP has them for about $17/pair with nuts.

 

[akfox1]

I ordered 5/3 and received mine 5/9 from VBP.

 

[GTR1999]

Bill did you check with Dana? He had them for $20 a couple of years ago.

 

[Bill75]

akfox1, I called VBP, they're on back order and won't be in for several weeks. Sounds like a conspiracy to me!!!!!!!!!!Yeah Gary, Dana is a good idea I haven't tried him yet, just thought I'd try for a new set.