72-80 Leaf spring swap, m880 springs

Posted By: smokes

72-80 Leaf spring swap, m880 springs - 05/22/13 02:45 AM

I am wondering if '77 Dodge m880 leaf springs are physically the same dimensions as my '78 half ton springs. My 1/2 ton leaf springs do not cut it for any sort of weight in the bed so I figured I would swap on some more heavy duty springs. I went to the wrecking yard and found a '77 m880 with a full suspension on it. I am taking the leaf springs, blocks and u bolts and leaf spring eyelet bolts. I just was double checking to make sure they are physically the same dimensions and will work on my truck? I know that the u bolts/ blocks may be different heights which is why i got them. Eventually I will get the 3/4 ton dana axles but for now I will be just replacing the springs. Any thoughts?

Posted By: 340SHORTY

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 02:51 AM

Yes they will fit. I put a set under mt 67 RC. Bolted right in. Lifted the rear about 2 to 3 inches..

Posted By: blaze

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 02:51 AM

Should be the same. I don't know why they wouldn't be a direct bolt-on replacement.

Posted By: smokes

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 02:58 AM

Quote:

Yes they will fit. I put a set under mt 67 RC. Bolted right in. Lifted the rear about 2 to 3 inches..

The rears look 2 or 3 leaves bigger than my 1/2 ones but the fronts look the same width? Do they lift the front as well?

Posted By: 340SHORTY

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 03:10 AM

The rears were all I had access to for the rears. The fronts will work also.. I add a Rear hi arc rear main leaf with the ends cut off to my front rc springs. The ride was firmer but not drasticly rough..

Posted By: NITROUSN

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 03:17 AM

The m880 are the same as other 3/4 ton w-200 springs. There is a 7 digit number on each spring which will identify its rating. Everyone thinks the m880 was some special built hd truck which it is not.

Posted By: BulletBob

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 04:45 AM

Everyone thinks the m880 was some special built hd truck which it is not.

Posted By: 76dodgeboy

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 08:47 PM

Wife cousin had one and sold to a friend that sold to a tard that tried getting $3000 for it and said it had some heavy duty trans (not a 727) and had was heavier duty. The military just rated things different

Posted By: smokes

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 10:33 PM

Quote:

Wife cousin had one and sold to a friend that sold to a tard that tried getting $3000 for it and said it had some heavy duty trans (not a 727) and had was heavier duty. The military just rated things different

Yeah, I noticed that when I was looking at the truck in the yard. Nothing that I saw underneath it or on the truck itself was any different than other 3/4 ton trucks from the same period.

Posted By: 76dodgeboy

Re: 72-80 Leaf spring swap, m880 springs - 05/22/13 10:51 PM

They were all 318 autos aswell

Posted By: hp383

Re: 72-80 Leaf spring swap, m880 springs - 05/23/13 07:59 AM

Quote:

Quote:

Yes they will fit. I put a set under mt 67 RC. Bolted right in. Lifted the rear about 2 to 3 inches..

The rears look 2 or 3 leaves bigger than my 1/2 ones but the fronts look the same width? Do they lift the front as well?

The front 3 leaf, leaf spring on the 1/2 and standard 3/4 (including the M88X) are the same spring. And will fit 72-93 trucks.

Same with the rear springs, 72-93 are direct fit.

The only oddball is the 93 diesel front spring. They changed the diameter of the bolt from 1/2 to 5/8. But these too can be a bolt in on a lighter duty truck with a sleeve for the smaller bolt.

Posted By: smokes

Re: 72-80 Leaf spring swap, m880 springs - 05/29/13 08:44 PM

Any one know if the u bolts and the plates are the same? I grabbed them all but just want to know if I need to clean the 3/4 ton ones up or if I can use my 1/2 ton ones that are clean.

Posted By: 76dodgeboy

Re: 72-80 Leaf spring swap, m880 springs - 05/29/13 09:11 PM

Fits ate same. Some say rears are diff depending on axle tube. I used 9.25 with a D60 and some roughcountry ubolts to load a truck on a trailer. They worked just fine other than having to open the holes for the aftermarket ubolts. Id say either rear should work but if you have the 3/4ton ones handy to clean Id clean and paint and have all ready for the swap

Posted By: krautrock

Re: 72-80 Leaf spring swap, m880 springs - 05/30/13 03:49 AM

the m880 is probably just a heavier rated rear leaf...as in there were probably a few different weight ratings available back then.

the front springs need to be stiffer IMO.
my truck rides and drives much better after putting stiffer springs in the front.

Posted By: smokes

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 03:25 PM

Quote:

Fits ate same. Some say rears are diff depending on axle tube. I used 9.25 with a D60 and some roughcountry ubolts to load a truck on a trailer. They worked just fine other than having to open the holes for the aftermarket ubolts. Id say either rear should work but if you have the 3/4ton ones handy to clean Id clean and paint and have all ready for the swap

That was my intention to clean them up a bit and to do the swap. I will soak them in Evapo-rust which is amazing. Harbor Freight sells the stuff and works awesome and much quicker than naval jelly or other rust removal chemicals. On another note if the front leaf springs are the same won't the rear of the truck sit about 2 inches higher? I was thinking about maybe installing an add-a-leaf to the front to make it more level?

Posted By: 76dodgeboy

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 04:04 PM

It might bring the rear up but not sure. You can always save some coin and pull a leaf from one of the front packs and put in the one you plan to use

Posted By: krautrock

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 05:24 PM

if you use the m880 block with the springs then it's probably going to sit higher in the rear.
not a big deal though because trucks should sit like that anyway right?

Posted By: smokes

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 05:32 PM

Quote:

if you use the m880 block with the springs then it's probably going to sit higher in the rear.
not a big deal though because trucks should sit like that anyway right?

Yes, I agree! I just don't want a huge rake, but an inch difference is fine.

Posted By: 76dodgeboy

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 05:37 PM

The block is no bigger than the Halfton block. The axle itself is what will make it a little taller and if the rear leaf from the M880 are used aswell they most likely have a few more leaf being a "Over rated" 3/4 ton. Just toss it together and see how she sits. To much rake plan accordingly

Posted By: hp383

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 06:16 PM

If you want a taller block, use one from a 91-93 Dodge diesel club cab 4x4 they used a factory 6" block, the rest were 4" or 5" i dont recall.

And there are some reports, and pictures, of factory 3" blocks on some models of trucks. I'm not sure what decided the block height on the trucks, it seems to be a mystery.

My Ramcharger has a diesel lift block in the rear, and I used an add-a-leaf to the front to level it out. Sits perfect and easily clears 33" tires on 9x17 wheels.

Posted By: 76dodgeboy

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 06:47 PM

They aren't even 4".

Posted By: krautrock

Re: 72-80 Leaf spring swap, m880 springs - 05/31/13 08:15 PM

yeah the block on my m880 is like 3" or maybe 3.5" i forget exactly.
mine does have a pretty aggressive rake with factory springs all around.

my truck has the factory rearend in it, dana60, so the axle tubes/spring perches might make the height of a 1/2 ton truck a little less than on an actual m880.

i still think you'll end up with some rake, it'll be fine though. get the rear together then decide what you want to do with the front.

btw there should be a metal plate on the dash in the m880 that list the weight ratings and all that stuff.

Posted By: NITROUSN

Re: 72-80 Leaf spring swap, m880 springs - 06/01/13 04:08 AM

Quote:

if you use the m880 block

There is no M880 block. A Special M880 is just a camo fart.

Posted By: krautrock

Re: 72-80 Leaf spring swap, m880 springs - 06/01/13 02:31 PM

Quote:

Quote:

if you use the m880 block

There is no M880 block. A Special M880 is just a camo fart.

i used that term to describe the block that should be on the m880 he's pulling the suspension parts from (because it's possible his truck might have a different block, who know...)

i didn't imply that the m880 has a "special" block or anything

Posted By: smokes

Re: 72-80 Leaf spring swap, m880 springs - 06/02/13 09:35 PM

Quote:

yeah the block on my m880 is like 3" or maybe 3.5" i forget exactly.
mine does have a pretty aggressive rake with factory springs all around.

my truck has the factory rearend in it, dana60, so the axle tubes/spring perches might make the height of a 1/2 ton truck a little less than on an actual m880.

i still think you'll end up with some rake, it'll be fine though. get the rear together then decide what you want to do with the front.

btw there should be a metal plate on the dash in the m880 that list the weight ratings and all that stuff.

Nice, I will have to go check to see if it is still there. I know I glanced at the dash and saw that the plate on the center left was missing. Hopefully that is not the one that has all the info. I think I might just throw the rears on and see how they sit before I redo the front springs.

Anyone know if a company makes urethane leaf spring bushings for the front or rear of these trucks? The m880 ones look ok but I would like to put in new ones before installation.

Posted By: hp383

Re: 72-80 Leaf spring swap, m880 springs - 06/02/13 09:39 PM

Quote:

Quote:

yeah the block on my m880 is like 3" or maybe 3.5" i forget exactly.
mine does have a pretty aggressive rake with factory springs all around.

my truck has the factory rearend in it, dana60, so the axle tubes/spring perches might make the height of a 1/2 ton truck a little less than on an actual m880.

i still think you'll end up with some rake, it'll be fine though. get the rear together then decide what you want to do with the front.

btw there should be a metal plate on the dash in the m880 that list the weight ratings and all that stuff.

Nice, I will have to go check to see if it is still there. I know I glanced at the dash and saw that the plate on the center left was missing. Hopefully that is not the one that has all the info. I think I might just throw the rears on and see how they sit before I redo the front springs.

Anyone know if a company makes urethane leaf spring bushings for the front or rear of these trucks? The m880 ones look ok but I would like to put in new ones before installation.

most of the lift kit companies also sell the spring eye bushings in urethane.

Posted By: 76dodgeboy

Re: 72-80 Leaf spring swap, m880 springs - 06/02/13 11:17 PM

Again that plate is just how the Military rated it. Its no different than a Powerwagon of the same yr. Its just a 3/4 ton that the military called a 5/4 or whatever they rated them. No heavier duty than the savilian Powerwagons