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However, that hole is covered when you have factory sway bar mounts. Have to the spring bolt, then install the sway bar mounts. Usually the head of the bolt is right up against the nut plate inside the trailing arm.
Also, I would be concerned with the shank of the bolt moving around and hitting the side of the hole.
True....no sway bar......a lot of Vette's came with rear bars and the one I did was bar delete as well.......
When first installed......yes, the nut sits a bit high......but the hole is big enough and it doesn't walk as much as one would think, BUT after a while the rubber crushes and the nut recedes a bit.
Of course.....if there is no need to do it.....then don't!
Wow there is a lot of bad information here but some good. First off let's clear up the TRW spring. There is no TRW spring, they do not make them anymore and when they did, it was the one you wanted. They were great springs when they were available and every one selling Corvette parts used them. I for one was not a huge fan of the VB&P Spring. We sold them, but I preferred the TRW. Yes there may be a current team running a steel spring, but they are running on 50+ year old technology and not better.
Thank You
Justin
I just happen to have a brand new TRW rear glass spring from the day. It's for sale cheap on the FS C1 C2. But no one seems to want it. I get it you like the glass springs but they are no better. And as far as 50+ year old technology it is still superior to most of the aftermarket crap that is produced today. And there are cars out there road racing and auto crossing to prove it.
I just happen to have a brand new TRW rear glass spring from the day. It's for sale cheap on the FS C1 C2. But no one seems to want it. I get it you like the glass springs but they are no better. And as far as 50+ year old technology it is still superior to most of the aftermarket crap that is produced today. And there are cars out there road racing and auto crossing to prove it.
I'm not going to get into the technical of this, but no the metal spring is not better than the fiberglass. If it were don't you thing the C7 would have a metal spring in it and not a fiberglass. So to compare that autocross car is fast only because it has a metal spring would be a huge injustice to the driver of that car. To say there are race cars that still run them, that would be correct there are several vintage series that are out there. I didn't say the steel ones were bad, I said they were older technology and that the earlier description of a steel vs. a fiberglass breaking were completely wrong. So If you took the LeMans L88 Corvette and ran it at VIR against say a C6 ZO6 who do you think would win that race. My bet would be the C6 with fiberglass springs. Nothing against the L-88 it is a cooler car, but the suspension does not work as well as the C6 with its different design and, fiberglass springs.
As far as the aftermarket crap. Take two apples or in this case two 68-72 Corvettes. Put one on F41 suspension and the other on the Detroit Speed suspension. Are you really saying that the one with F41 suspension would win with everything else being equal? Wait Danny Popp has Vansteel suspension in his with coil overs. Has any bone stock suspension cars beat him? Look, it is not about what I like better, I like bone stock cars just as much as modified, but your statements are way off. Of course there are bad aftermarket parts, but you get what you pay for. I meant don't expect Chinese coil overs to perform as well as a set of Bilstein or Penske or QA1 or JRI coils. The stock suspension in our Corvettes was awesome in the 60's and ahead of its time, but it was surpassed a long time ago.
Last edited by Zip Corvettes; Mar 19, 2020 at 03:30 PM.
?? who sold you the incorrect one. We have been selling the same one for decades with no issues. Did you try and call anyone instead of spending days figuring something out?
From: Loud, Raw and Dangerous 1968 327 4S in Southern California
Originally Posted by J.Abbott
Odd, it should not have been.
I agree...the steel sheathed rear cable effective length should not have changed. Only thing I can think of is something else interfered with another part of the cable. I did not take the time to see what after seeing where the end of the longer bolts ended up in relation to the ground and rim. Next time the car is on a lift I will investigate further.
I was going to stay out of this but I can't let all the bad info in this thread go. It has been well known on this forum for over 15 years that the TRW style springs manufactured by Muskegon Brakes commonly have too much arch. Yet the Corvette parts sellers still sell them and play innocent when someone has an issue. Its pretty simple; if you are manufacturing a spring that requires 10" bolts for proper ride height, they should be included with the spring. The reason they aren't included? Because they are unsafe as the following pictures illustrate.
The spring end can gouge the tire sidewall and cause a blowout under spirited driving. 10" bolts are not an option! If the spring requires 10" bolts for an acceptable ride height; it is defective and should be returned to the seller for a full refund including shipping.
Last edited by Kid Vette; Mar 19, 2020 at 05:30 PM.
From: Loud, Raw and Dangerous 1968 327 4S in Southern California
Wow....that must have been a noisy blowout. I wonder what happens when a composite spring breaks in the middle? Does the fiberglass body fall down and contact the wider tires?
I was going to stay out of this but I can't let all the bad info in this thread go. It has been well known on this forum for over 15 years that the TRW style springs manufactured by Muskegon Brakes commonly have too much arch. Yet the Corvette parts sellers still sell them and play innocent when someone has an issue. Its pretty simple; if you are manufacturing a spring that requires 10" bolts for proper ride height, they should be included with the spring. The reason they aren't included? Because they are unsafe as the following pictures illustrate.
The spring end can gouge the tire sidewall and cause a blowout under spirited driving. 10" bolts are not an option! If the spring requires 10" bolts for an acceptable ride height; it is defective and should be returned to the seller for a full refund including shipping.
This is exactly what I was talking about in my earlier post.
I urge you to replace that spring with a proper and safe spring and bolt set up in your car.
If I remember correctly the blowout pictured above occurred at a low speed.
Just imagine at highway speed.
Zip already agreed to take the spring back.
Why risk it?
The solution is not longer bolts. A work-around is longer bolts. Did GM ever use 10" bolts from the factory? I'd love to be proven wrong, so I'm asking. Please reference a GM part number if they did.
I'm glad to see Zip stand by their product. I've had nothing but great customer experiences with them. Perhaps this spring is correct if you fix the front springs and go for the lifted 4x4 look with your Vette. But if they can exchange this TRW-style Muskegon spring for a low-arch VanSteel spring, I think you will be happier.
The reason why GM didn't offer a 10" bolt was because GM never used a short tire and all the new Corvettes looked like 4x4's. The arch of the spring also depends on the spring rate of the spring. If you look at the GM original springs a 9 leak has more arch than a 7 leaf and a 5 leaf Daytona is pretty much flat. 10" is absolutely the way to go and he may have to trim them a little, no harm in that at all.
Thanks for replying, and thanks for making my point. For the 14 years that GM sold the third generation of America's Sports Car, they cut corners by leaving out the transfer case and front differential, but kept the 4x4 look.
If the TRW-style Muskegon leaf spring matches the arch of a non-sagged 9-leaf original GM spring, and I bet it's arched even more than that, fine. That's what you get. But the low-arch VanSteel spring (and the VB&P before) attempt to recreate the low-arch of the 7-leaf gymkhana spring. And for a modern C3 owner, that has to be a better option than the 10" bolts
Here's the obligatory photo of my 80s rear end, with the VB&P spring, 8" bolts (only using 7), and nearly flat half-shafts. And no spare tire, either. She sits on 255/60R15s, which is a stock tire size.
Perhaps if these threads keep ending up on the Forum, we can save a future member some grief.
After reviewing all the great information that came from your post string and looking at my car again, I think I am just going to leave the stance of my car alone. If anybody asks I will tell them it is designed that way to improve the torque transfer from the wheels to the pavement during 1st gear burn outs. Best of luck in your quest!
Side view with 1.5 inch rear higher.
Tell them the wedge shape is to push the rear of the car down at higher speeds. It prevents oversteer. GM did this with J-Body cars, like this Cavalier.
Originally Posted by Redvette2
Wow....that must have been a noisy blowout. I wonder what happens when a composite spring breaks in the middle? Does the fiberglass body fall down and contact the wider tires?
There are rubber bumpers that should prevent the trailing arm from moving too far upwards. If you've removed these bumpers, or run wide tires beyond the fenders without flares, that's on you.
From: Loud, Raw and Dangerous 1968 327 4S in Southern California
Originally Posted by Bikespace
Tell them the wedge shape is to push the rear of the car down at higher speeds. It prevents oversteer. GM did this with J-Body cars, like this Cavalier. There are rubber bumpers that should prevent the trailing arm from moving too far upwards. If you've removed these bumpers, or run wide tires beyond the fenders without flares, that's on you.
Thanks...I also was thinking that extra wheel space in the back is to help generate more smoke during the burnouts. As far as the bumpers...yes my tires are right at the edge of the fender. Going to look for those bumpers first thing tomorrow.
Edit Update: I have bumpers...whew.
Last edited by Redvette2; Mar 20, 2020 at 02:05 PM.
Thanks...I also was thinking that extra wheel space in the back is to help generate more smoke during the burnouts. As far as the bumpers...yes my tires are right at the edge of the fender. Going to look for those bumpers first thing tomorrow.
Better launches, smokier burnouts, and oversteer reduction at speed? <sarcasm> Perhaps the high-arch TRW-style spring is the way to go! </sarcasm>
Some trim them to get the car extra low, but I believe they are shaped the way they are to prevent the abrupt bumps (changes in spring rate) that you would get with a flat bumper. If you unbolt your rear spring, you can check to see if the car will rest on the bumpers before resting on your fenders.
What fool would use a bolt with EXCESSIVE length and not cut it off? That was the problem....not that the bolt was longer. Let's get real with 'causal relationships'.
I'm not going to get into the technical of this, but no the metal spring is not better than the fiberglass. If it were don't you thing the C7 would have a metal spring in it and not a fiberglass. So to compare that autocross car is fast only because it has a metal spring would be a huge injustice to the driver of that car. To say there are race cars that still run them, that would be correct there are several vintage series that are out there. I didn't say the steel ones were bad, I said they were older technology and that the earlier description of a steel vs. a fiberglass breaking were completely wrong. So If you took the LeMans L88 Corvette and ran it at VIR against say a C6 ZO6 who do you think would win that race. My bet would be the C6 with fiberglass springs. Nothing against the L-88 it is a cooler car, but the suspension does not work as well as the C6 with its different design and, fiberglass springs.
As far as the aftermarket crap. Take two apples or in this case two 68-72 Corvettes. Put one on F41 suspension and the other on the Detroit Speed suspension. Are you really saying that the one with F41 suspension would win with everything else being equal? Wait Danny Popp has Vansteel suspension in his with coil overs. Has any bone stock suspension cars beat him? Look, it is not about what I like better, I like bone stock cars just as much as modified, but your statements are way off. Of course there are bad aftermarket parts, but you get what you pay for. I meant don't expect Chinese coil overs to perform as well as a set of Bilstein or Penske or QA1 or JRI coils. The stock suspension in our Corvettes was awesome in the 60's and ahead of its time, but it was surpassed a long time ago.
For one thing I'm not trying to convince anyone to buy my parts so I can keep my job. And I never said the metal spring was better than the glass one. I said the glass is no better then the metal . And this hole thing started because I said glass springs can break. Well they can. And I never said the autocross car was better because it had a metal spring. Just trying to get across that you can make a stock style suspension work very well even if it is 50 year old tec.You want to put a F41 suspension up against the Detroit Speed 25 thousand dollar suspension come on man. Why would you want to run F41 there are way better options in a stock style C2 C3 form." Wait" Danny Popp. How about "Wait" Brian Hobaugh. That's weird Brain Hobaughs 65 ended up dead even with a C6 what the hell it has stock style suspension. Hot Rod did an article on it read it. But wait what about Brent Jarvis 65 ran same time at road America as a 2015 ACR Viper. I do have to say he was running a composite rear spring that must have been it.
yes 10” bolts will solve it. use NYLOCK nuts then set the ride height. Cut off any remaining thread and
make sure they do not go past the bottom of the wheels. If you have a flat tire, it could get ugly for the rear suspension.
I was going to stay out of this but I can't let all the bad info in this thread go. It has been well known on this forum for over 15 years that the TRW style springs manufactured by Muskegon Brakes commonly have too much arch. Yet the Corvette parts sellers still sell them and play innocent when someone has an issue. Its pretty simple; if you are manufacturing a spring that requires 10" bolts for proper ride height, they should be included with the spring. The reason they aren't included? Because they are unsafe as the following pictures illustrate.
The spring end can gouge the tire sidewall and cause a blowout under spirited driving. 10" bolts are not an option! If the spring requires 10" bolts for an acceptable ride height; it is defective and should be returned to the seller for a full refund including shipping.
That must have been an interesting ride. Two thoughts:
1) End of bolt should have been trimmed.
2) Blowout is nowhere near where the end of the spring is. It is much closer to the tread.
What fool would use a bolt with EXCESSIVE length and not cut it off? That was the problem....not that the bolt was longer. Let's get real with 'causal relationships'.
The problem was the end of the spring punctured a hole in the sidewall of the tire. The end of the bolt could have been cut off and you still would have had the same relationship of the end of the spring to the tire with the same result of the punctured tire.
yes 10” bolts will solve it. use NYLOCK nuts then set the ride height. Cut off any remaining thread and
make sure they do not go past the bottom of the wheels. If you have a flat tire, it could get ugly for the rear suspension.
make sure they do not go past the bottom of the wheels. If you have a flat tire, it could get ugly for the rear suspension.
I think herein is the rub. I have the 10-inch bolts on order. If it looks unsafe with any bit reaching beyond my stock rims, I will return the spring.
