The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-15-2018, 10:54 AM   #1
Faastone27
Registered User
 
Faastone27's Avatar
 
Join Date: Nov 2017
Location: Johns Creek Georgia
Posts: 64
how much to cut off coil spring?

Hey guys I'm in the process of completely rebuilding my front end. The guy i purchased the truck from simply heated the coils to collapse and lower the truck( i know that is totally the wrong way) So now i decided to do it correctly and i ordered 2.5 drop spindles and 1"lowering springs. But i want a total of 5" drop so obviously that means i need to cut another 1.5 " off my coils to get desired drop About how much should i cut off the coils to achieve another 1.5" i think one full coil would be to much? Thanks for your help
Faastone27 is offline   Reply With Quote
Old 01-15-2018, 10:59 AM   #2
LEEVON
Moderator
 
LEEVON's Avatar
 
Join Date: Jul 2006
Location: Ozark, MO
Posts: 4,888
Re: how much to cut off coil spring?

From experience, 2.5 spindles and 1" springs will be lower than you think. I would put them in and see where you're at then cut as needed. but no more than 1/4 round at a time. It's always been trial and error for me.
__________________
'20 Silverado Trail Boss ~ '17 Tahoe ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '71 Cheyenne swb ~ '55 Pontiac Safari ~'50 3100 bagged ~ '80 Wife ~ Late model kids
LEEVON is offline   Reply With Quote
Old 01-15-2018, 11:02 AM   #3
Faastone27
Registered User
 
Faastone27's Avatar
 
Join Date: Nov 2017
Location: Johns Creek Georgia
Posts: 64
Re: how much to cut off coil spring?

Quote:
Originally Posted by LEEVON View Post
From experience, 2.5 spindles and 1" springs will be lower than you think. I would put them in and see where you're at then cut as needed. but no more than 1/4 round at a time. It's always been trial and error for me.
OK That is probably a good idea. I know from previous experience that it will also settle a little with all new components. Thank You!
Faastone27 is offline   Reply With Quote
Old 01-15-2018, 11:05 AM   #4
LockDoc
The Older Generation


 
LockDoc's Avatar
 
Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 25,769
Re: how much to cut off coil spring?

-
Normally cutting one coil off of the fronts gives a 2 1/2" drop.

LockDoc
__________________
Leon

Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles

(My Dually Pickup Project Thread)

http://67-72chevytrucks.com/vboard/s...d.php?t=829820

-
LockDoc is offline   Reply With Quote
Old 01-15-2018, 12:12 PM   #5
Faastone27
Registered User
 
Faastone27's Avatar
 
Join Date: Nov 2017
Location: Johns Creek Georgia
Posts: 64
Re: how much to cut off coil spring?

Quote:
Originally Posted by LockDoc View Post
-
Normally cutting one coil off of the fronts gives a 2 1/2" drop.

LockDoc
Thank You i figured one full coil would be to much. I think I'll do 1/4 coil and check it from there and sneak up on the desired drop/ Also i have been reading up on bump steer fixes and came across a great thread with solving this I believe i will also do this while I'm at it.
Faastone27 is offline   Reply With Quote
Old 01-15-2018, 10:53 PM   #6
Rod Run
Registered User
 
Rod Run's Avatar
 
Join Date: Oct 2013
Location: Massachusetts
Posts: 777
Re: how much to cut off coil spring?

Anything more than one coil is going to make your ride much more harsh. Usually if you need more drop than that, you would want to buy a different coil
__________________
______________________
www.northeastrodrun.com
Rod Run is offline   Reply With Quote
Old 01-16-2018, 05:22 PM   #7
CC69Rat
Registered User
 
CC69Rat's Avatar
 
Join Date: Jan 2011
Location: Chattanooga TN
Posts: 6,212
Re: how much to cut off coil spring?

Quote:
Originally Posted by Rod Run View Post
Anything more than one coil is going to make your ride much more harsh. Usually if you need more drop than that, you would want to buy a different coil
I second this ^^ -- Think of a diving board that's 12 ft long. a 250lb guy jumps on the end, it recoils, and boing he's in the water. The diving board is designed for a sepecific weight and torsional rigidity.

Now, lets cut 2 ft off the diving board. Same guy .. bounces on one end.. is the board stiffer or softer ? Your coil spring is going to work the same way. I understand making the spring shorter to lower the truck but that spring is nothing more than a thick metal bar that's coiled up to form a spring and torsional rigidity. Cutting the spring lowers the truck, yes.. but it also changes the spring rate much like that diving board.

Also, if you cut it off, use a grinder / ziz wheel not a torch. Heat will also weaken the spring. Cut springs work, yes but I've never talked to anyone who likes the ride quality afterward. It will make your truck ride like a train car. I'd sell the 1" drop and buy some 2" if you want it lower. .. just me. Hope this helps.
__________________
Chad

1967 C10 SWB - Project Savannah - 6.0/4L80 *Currently underway*
1968 C10 SWB - TOTY 2018, 50th Anniversary Tribute Project * Sold * Pride and Joy
1986 Silverado Short Fleet - Scarlet *Sold*
1985 Silverado Short Fleet *Sold*
2022 Jeep Gladiator Mojave
2001 Jeep Cherokee XJ 4x4 - Lifted, Built
1992 Jeep Cherokee XJ 4x4 - Lifted
2013 Honda Accord EX-L v6 Coupe 6spd (wife's ride)
CC69Rat is offline   Reply With Quote
Old 01-16-2018, 09:14 PM   #8
RenoKeene
Florida Edition

 
RenoKeene's Avatar
 
Join Date: Oct 2010
Location: Fruitland Park, FL
Posts: 4,028
Re: how much to cut off coil spring?

What you have will be enough drop without clearance problems. Put it together and take a look at it. You can always cut a spring if you don't like it.
__________________
70 GMC Short Stepside "Rose"-An American Beauty: Factory 402/TH400, AM/FM, AC, Tilt, Tach, Buckets, Posi, PS, PB, 3-5 Drop, Complete Resto-Rod
67 C-20 Slant Back Wrecker "Mad Max"
67 C-10 Ratrod "Step-N-Wolf"
71 Serro Scotty Sportsman camper "Scotty"
97 LT1 Z28 "The Hornet"

Link to more pics of "Rose" http://67-72chevytrucks.com/vboard/a...p?albumid=1684

Check out my "Cheap Tricks" thread and add to it if you can, lots of good info there. http://67-72chevytrucks.com/vboard/s...d.php?t=489394
RenoKeene is offline   Reply With Quote
Old 01-16-2018, 10:55 PM   #9
LEEVON
Moderator
 
LEEVON's Avatar
 
Join Date: Jul 2006
Location: Ozark, MO
Posts: 4,888
Re: how much to cut off coil spring?

I know you already ordered 1" lower springs, but for what it's worth I have a recipe that has worked great for the last 6 or 7 trucks. I combine 2.5" spindles with HD coils and one round cut. What are HD coils you ask? Well, for example search Rockauto for coil springs on a C20 and other trucks. You will find four or five part numbers, with details of the winding thickness, load rating, and length. I use a Moog spring that is a little longer, thicker wound and has a higher load. That way, after one round is cut, your back to the original capacity. Rides like a dream, combined with a sway bar. I don't remember the part number at the moment.
__________________
'20 Silverado Trail Boss ~ '17 Tahoe ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '71 Cheyenne swb ~ '55 Pontiac Safari ~'50 3100 bagged ~ '80 Wife ~ Late model kids
LEEVON is offline   Reply With Quote
Old 01-17-2018, 08:48 AM   #10
Faastone27
Registered User
 
Faastone27's Avatar
 
Join Date: Nov 2017
Location: Johns Creek Georgia
Posts: 64
Re: how much to cut off coil spring?

Thank You all for your input. I hopefully will be putting it back together today if I can get to my shop. we got some snow last night and wasn't even able to get out of my sub. I did cut 1/2 coil off thinking it should get me close to my desired drop. No big deal to change them out if I need too! LOL!

EDIT: So i went aheqad and just purchased 2" lowering springs. They were only $99.00 Thought that was the right thing to do!

Last edited by Faastone27; 01-17-2018 at 12:08 PM.
Faastone27 is offline   Reply With Quote
Old 01-17-2018, 01:22 PM   #11
LEEVON
Moderator
 
LEEVON's Avatar
 
Join Date: Jul 2006
Location: Ozark, MO
Posts: 4,888
Re: how much to cut off coil spring?

Just in case, found an old post I made with the part number:

MOOG 6454 springs. They start at 13.61" free height, have a load rating of 3841 lbs, and a spring rate of 1060 lbs. Here are the specs.

http://www.rockauto.com/catalog/moreinfo.php?pk=200827
__________________
'20 Silverado Trail Boss ~ '17 Tahoe ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '71 Cheyenne swb ~ '55 Pontiac Safari ~'50 3100 bagged ~ '80 Wife ~ Late model kids
LEEVON is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:50 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com