Hey Y'all

Im working on my 85 Chevy 3/4 ton 2wd Suburban

I Found a Suburban In a bone yard that has a 3/4 ton Full Float 3:73 open carrier Diff . . .

~~I was needing to know what will be the difference in putting that rear in place of the 14 bolt semi float that is in there

~~I need to know if the spring perches are the same

~~Shock mounts are the same

~~Drive shaft yolks are the same

~~& if there is any thing else that i might have to change or that wont make it work

Any & All Info is greatly appreciated
I'm gonna pull the cover & give it a good inspection before I have them take it out of the junk truck

Oh ! Also I want to pull the carrier bearing caps to make sure they are not spinning.

~~ What is the torque specs on those big bolts?

~~How do I check the gear ratio too ?

Here I go again Hopefully I get a good working rear & get my bus on the road Its been Parked for almost 2 years.
Then I can get fron 6MPG to maybee 15MPG


Thanks in Advance :cool:

SR66 :D
http://hotrodders.com/gallery/data/500/medium/slowrides_pictures_net_026.jpg

I have a 1990 3/4 4x4 suburban that I swapped in a 14ff to replace the 14SF. The perches were exactly the same. The pinion U-joint was the same on both:1350. Be careful if you are really looking for an open diff. I thought mine was open because the tires spun in diifrent directions, but once I got it to the diff shop, I found out that it had the Gov-Lock. Probably not a big deal for you since you have 2wd. I don't think you will have any problems.

The shock mounts are a little lower for the FF, probalby 1-2 inches. Everything else should be just fine.

I count 8 lug nuts. (at least on the front) don't you already have a full floater? I didn't know they put the sf in trucks in 85.:confused:

they did. they started that in like 81 or 82.

Yes the truck is a factory SF with 4:10 Governor lock{its on the glove box door}

I will go back to a Posi probally a Eaton but I can't afford the $2000. for all the parts to rebuild the SF

Its completely junk even the housing.

The races are spinning in the housing.:shaking:

The Posi has come in handy a few times but as you can see this truck is a pavement pounder:laughing:

If the one I found in the bone yard is good its a 14 bolt open 3:73 which I was gonna go up to that to maybe get a few more MPG's

It was getting close 15 on the hwy last time I drove it gas was $2.00 a gallon!:rolleyes:

The Lil small block don't have enuf to spinn the tires.

Thanks alot

See 8 on the back too LOL

http://hotrodders.com/gallery/data/500/medium/slowrides_pictures_net_023.jpg


SR66:D

The gear ratio should be on the side of the ring gear and will read something like 41-10 for example, which is 41/10=4.10 gear ratio. As for open or gov-lock, in the 14FF axle, the carrier is a 2-piece design and has little "windows" where you can see the side/spider gears. If it has 3 windows it's a Gov-Lock, if it has 4 windows, it's an open.

ITS DONE!!!!!!!!!!!

Thank God it was a long, greasy, messy, loney road but done .

Check out my Journal\http://www.hotrodders.com/forum/journal.php?s=&journalid=19078&action=view#85 Suburban

Thanks for all the help from here!!:D

SR66:D

is there a difference between a 3/4 ton 14 bolt and a 1 ton 14 bolt?

are they both 8 lug and FF?

Well I'm not Exactly sure but here is what I do know
I've never seen a "factory C-30 /3500 Suburban {that don't mean its not true}

a far as I know there are 3 options for these years
Van- Dually & Pick Up/Suburban are different in the width & spring mounts .

95% sure on that info.. .. ..


SR66

I did the same upgrade on my '84 2wd Burb - except I found a thriftier axle ratio :p

is there a difference between a 3/4 ton 14 bolt and a 1 ton 14 bolt?

as far as the trucks go...

1-ton spring spacing is 2" narrower and the shocks mount inboard of the frame.

1-tons usually have 1" wider drums/shoes. (SRW drums, shoes, and backing plates can be swapped as a set to upgrade a 3/4-ton.)

Vans are a different animal as far and lengths, widths, and spring spacing. The hubs are brakes are the same though.