3/4 ton or 1ton axle?

Bare Foot Garage · March 11, 2022

Hello all,

New here. Don't post on forums much ever but have a question.

Just purchased a 1995 gmc suburban LT (I believe) has a 454 under the hood. First gen 4L80E (one with cooling lines both near front, Not split up on opposite ends)

Long story short I know I have a full floating "corporate" 10.5 rear end but I don't know how to tell if it's a 3/4 ton or 1 ton. *laughs*

Guessing 3/4 ton is semi- floating and 1 ton is full but I can't find anything online.

I know your saying "but k2500 suburban never came with a 1ton axle..."

I was told from previous owner a previous owner of the truck swapped the rear axle with a 1 ton dually. So I am trying to track down info how to verify frame, drivetrain, rear diff etc if it's a 1ton or not.

One of the previous owners put "dually" rear tires on it which I like alot BUT want to make sure if it's a 3/4ton and not a 1ton that I can handle that.

Also it still has drum brakes in the rear (havnt taken tires off yet to check condition there lol) and disc front. So I know it's not a newer rear axle that had disk brakes. Or disc brake conversion welded on...

A body swap is one possibility cause frame doesn't look spliced or "tweaked" and looks all "stock."

If you have questions on things I need to look for please ask.

I have been told it was duallified (horrible I know) "professionally" but am leaning towards the previous seller was pulling my leg. Or telling me what he was told. Which still seems possible bs.

Thanks again all

Mr. Kate @ Bare Foot Garage

CamGTP · March 11, 2022

This picture best shows the difference.

A full float rear axle lets you remove the axle shaft without even opening the rear end.

Bare Foot Garage · March 11, 2022

Thanks! That deff confirms I have a full float axle but doesn't confirm if it's a 3/4 ton axle or 1 ton lol

Did 1995 suburbans' ever come with the 1 ton full floating axle?

Thanks again!

Z45 · March 11, 2022

NO, not on regular production 2500 available to the general public. We had K2500 'burbans on our DOT GPS Survey Teams and they were K2500 on a K3500 chassis, special gov't fleet with a F&SO code in glove box. According to my friend who was parts manager at local Chevy dealer who serviced my 1999 burb, only the special fleet vehicles got those and every time they needed to order parts, they had to have that F&SO code. There was always a 1 yr lead time to get our replacements because Chev would only build them at the start of model year production.

Edited March 11, 2022 by elcamino

Bare Foot Garage · March 11, 2022

Wow! That's cool! Thank you for that. I am a complete "newb" when it comes to 90's chevy / GMCs. So I truly appreciate all help from all.

Do you know what the F&SO code looks like? Or is it just that "F&SO"?

Also do you know what visual differences are between the 3/4 ton axle and a 1 ton axle?

Sorry for asking so much. I havnt been able to find info online. Damn Google saying I am gonna die when I look for 3/4 ton "corporate" axles *laughs*

Nate

newdude · March 11, 2022

1 hour ago, Bare Foot Garage said:

Wow! That's cool! Thank you for that. I am a complete "newb" when it comes to 90's chevy / GMCs. So I truly appreciate all help from all.

Do you know what the F&SO code looks like? Or is it just that "F&SO"?

Also do you know what visual differences are between the 3/4 ton axle and a 1 ton axle?

Sorry for asking so much. I havnt been able to find info online. Damn Google saying I am gonna die when I look for 3/4 ton "corporate" axles *laughs*

Nate

3/4 and 1 ton 10.5" full float are the same axle for single rear wheel. Dually 1 ton would have different hubs on the ends of it.

10.5" is factory axle for a 2500 with 454.

Z45 · March 11, 2022

1 hour ago, Bare Foot Garage said:

Do you know what the F&SO code looks like? Or is it just that "F&SO"?

Also do you know what visual differences are between the 3/4 ton axle and a 1 ton axle?

Sorry for asking so much. I havnt been able to find info online. Damn Google saying I am gonna die when I look for 3/4 ton "corporate" axles *laughs*

Nate

It was just a 5 digit number that reference back to the order for the vehicle such as F&SO 12345.

The only difference I recall was the brakes were larger on our trucks and we had a 45 gal fuel tank. The Chevy dealer found that out when they ordered brakes parts for a 3/4 ton and they were too small and the had to reorder parts. Other that I drove it for 4 yrs and 125,000+miles and never had any issues.

F&SO - Fleet and Special Order (COPO)

Edited March 11, 2022 by elcamino