Needed measurements for 56 in leaf mounts. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

muddstir · 05-21-2012, 11:58 PM

I'm in need of some measurements for the rear leaf mounts on a 73-80 (or 81-87 if frames are the same) longbed with 56in leafs.

Story- My 1980 3/4 4x4 longbed frame rusted out and then the one leaf mount broke away. So I replaced the frame with another one ( I think it's a 1975) switched all mounts over to new frame and scraped the old broke one. Once I bolted the leaf springs in I realized that the rear shackle was all the way back with the spring resting in the mount. Found out that the set up was for 52's not my 56's. I'd really like to keep my springs that I have so I'm willing to drill new holes but I need to know where to drill to keep axle centered. If any body could get these measurements it would help out greatly.

The pic shows one side but if I could get both sides due to the placement of the shocks that would be the best.

WHITE- From the end of the frame rail to the center of the 1st or 2nd top rivet/ hole on rear leaf mount.
HOT PINK- From the center of the shock hole to nearest top rivet/ hole on the rear leaf mount
RED- From the center of the shock hole to the nearest rivet/ hole on the front leaf mount
GREEN- From the center of the inner top rivet/ hole on the rear leaf mount to the center of the nearest top rivet/ hole on the front leaf mount

If anybody knows of a different way of doing it plz let me know.
Name: Copy of DSCF0259.jpg
Views: 293
Size: 65.7 KB

Name: Copy of DSCF0259.jpg
Views: 293
Size: 65.7 KB

**special-K** · 05-22-2012, 07:04 AM

The difference is all to the rear. From center to center of the rear rivets on the front hanger to the front rivets on the rear hanger measures 48 1/4" for both.

muddstir · 05-22-2012, 07:58 AM

Quote:

Originally Posted by special-K

The difference is all to the rear. I can measure my Suburban this evening.

Went out and put both hangers on with the spring pack and it does look like the center pin is in line with the bump stop mount on the frame.
But then how does that work I'm assumeing center pins would be in the center of the length of the leafs. You put longer leafs on wouldn't it kick the axle back (unless they have more arch to them.)

**special-K** · 05-22-2012, 10:36 PM

I guess the 56" leaf center pins are off center. I swapped the axles and springs from my '91 3/4t Suburban to my '85 Jimmy. I decided not to move the rear spring mounts back,bought new 52" springs,and they bolted on. I was thin king I'd have to get the Suburban axle shortened for the Jimmy,since it had the larger 14-bolt axle now. But,with the 4" lift made up for the bigger rear and the Jimmy driveshaft bolted right in (with a conversion u-joint). So,the front spring eye to axle center is the same on 52" and 56" springs.

SunSoaked · 05-23-2012, 06:55 PM

FYI-throwing knowledge out there for whoever might need some

I removed the REAR 56 leafs/brackets off the 1008 today and took the following measurements:

Front spring eye to center pin=26"
Rear spring eye to center pin= 29 5/8th
Confirms there is an offset

Bracket (front of rear spring (center of hole)) to center bumpstop=25 5/8th
Bracket (rear of rear spring (center of hole)) to center bumpstop=30"

Remember the rear has the shackle between the bracket and spring. Its 4" center of holes (6" overall).

rayfinseats · 05-26-2012, 12:38 AM

I put 74 dodge 3/4 ton springs on the front of my 83 k10. 2" lift and rides way better. It moved front axle 1/2 inch to rear.

05-21-2012, 11:58 PM	#1
muddstir Registered User Join Date: Jan 2011 Location: Transfer, Pa Posts: 110	Needed measurements for 56 in leaf mounts. I'm in need of some measurements for the rear leaf mounts on a 73-80 (or 81-87 if frames are the same) longbed with 56in leafs. Story- My 1980 3/4 4x4 longbed frame rusted out and then the one leaf mount broke away. So I replaced the frame with another one ( I think it's a 1975) switched all mounts over to new frame and scraped the old broke one. Once I bolted the leaf springs in I realized that the rear shackle was all the way back with the spring resting in the mount. Found out that the set up was for 52's not my 56's. I'd really like to keep my springs that I have so I'm willing to drill new holes but I need to know where to drill to keep axle centered. If any body could get these measurements it would help out greatly. The pic shows one side but if I could get both sides due to the placement of the shocks that would be the best. WHITE- From the end of the frame rail to the center of the 1st or 2nd top rivet/ hole on rear leaf mount. HOT PINK- From the center of the shock hole to nearest top rivet/ hole on the rear leaf mount RED- From the center of the shock hole to the nearest rivet/ hole on the front leaf mount GREEN- From the center of the inner top rivet/ hole on the rear leaf mount to the center of the nearest top rivet/ hole on the front leaf mount If anybody knows of a different way of doing it plz let me know. __________________ 1970 4x4 1/2 lwb -new ride- 1971 2x4 1/2 lwb -yard ornament 1980 4x4 3/4 lwb -currently dismantled 1997 chevy cavalier =daily driver 1998 chevy cavalier -full coverage plan 2007 kawasaki vulcan 900 - garage ornament

05-22-2012, 07:04 AM	#2
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: Needed measurements for 56 in leaf mounts. The difference is all to the rear. From center to center of the rear rivets on the front hanger to the front rivets on the rear hanger measures 48 1/4" for both. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 05-22-2012 at 07:50 AM.

05-22-2012, 10:36 PM	#4
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: Needed measurements for 56 in leaf mounts. I guess the 56" leaf center pins are off center. I swapped the axles and springs from my '91 3/4t Suburban to my '85 Jimmy. I decided not to move the rear spring mounts back,bought new 52" springs,and they bolted on. I was thin king I'd have to get the Suburban axle shortened for the Jimmy,since it had the larger 14-bolt axle now. But,with the 4" lift made up for the bigger rear and the Jimmy driveshaft bolted right in (with a conversion u-joint). So,the front spring eye to axle center is the same on 52" and 56" springs. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

05-23-2012, 06:55 PM	#5
SunSoaked Registered User Join Date: Dec 2011 Location: Yuma Arizona Posts: 1,525	Re: Needed measurements for 56 in leaf mounts. FYI-throwing knowledge out there for whoever might need some I removed the REAR 56 leafs/brackets off the 1008 today and took the following measurements: Front spring eye to center pin=26" Rear spring eye to center pin= 29 5/8th Confirms there is an offset Bracket (front of rear spring (center of hole)) to center bumpstop=25 5/8th Bracket (rear of rear spring (center of hole)) to center bumpstop=30" Remember the rear has the shackle between the bracket and spring. Its 4" center of holes (6" overall). Last edited by SunSoaked; 05-23-2012 at 06:58 PM. Reason: Its 103 out today...hello

05-26-2012, 12:38 AM	#6
rayfinseats Registered User Join Date: Dec 2010 Location: sioux city, iowa Posts: 619	Re: Needed measurements for 56 in leaf mounts. I put 74 dodge 3/4 ton springs on the front of my 83 k10. 2" lift and rides way better. It moved front axle 1/2 inch to rear.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.