Author Topic: 14 bolt SF vs. 14 bolt FF:  (Read 390 times)

Offline Stewart G Griffin

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14 bolt SF vs. 14 bolt FF:
« on: June 11, 2018, 08:52:33 AM »
(NOTE: i am looking for the right tow vehicle and want to do it right, and thus i'm asking a lot of basic questions, so please bear with me.)

When did Chevy stop equipping the suburban with the 10.5" Full-floating 14 bolt diff in 3/4 suburbans (and i'm assuming in 3/4 ton trucks) as standard equipment?

Could you still get a Full-floater as an option after the change?

Offline 75gmck25

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #1 on: June 11, 2018, 05:03:57 PM »
Based on the information on this page, it was a 14 bolt FF until 1981, and then the SF was standard.  http://www.chuckschevytruckpages.com/73-87specs.html

My '75 GMC K25 3/4 ton Camper Special has the 14 bolt FF with 4.10 ratio, and its not listed as a separate option, so it was apparently standard.

Bruce

Offline zieg85

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #2 on: June 11, 2018, 07:52:07 PM »
454 had the 14 bolt FF up to 1991
1985 C30 Custom Deluxe Ext. cab 5.7L TH400 4.56 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Irish_Alley

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #3 on: June 12, 2018, 07:01:58 AM »
i have a 454 in my 91 crew. stew what are you wanting out of the tow vehicle? do you want something that can haul a lot of people or do you want that covered cargo space the burb offers? if i had the chance to do it again i would prob buy that 99 burb with the 6.5(think that was the year) that i looked at a few years ago. also why are you stuck on the 14 bolt?
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Offline Irish_Alley

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #4 on: June 12, 2018, 07:07:16 AM »
also according to the 14 bolt bible, the FF was in trucks till 2000

Quote
The 14bolt is found in a huge number of GM 4x4 pickup trucks and vans, 3/4 and 1 ton, from the 70's right through until at least 2000. You can find it in:

73-96 C20, C2573-00 C30, C3573-00 G30, G3573-00 K20, K2573-00 K30, K3584-88 CUCV
88-91.5 V30
http://www.pirate4x4.com/tech/billavista/14b_bible/
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Offline zieg85

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #5 on: June 12, 2018, 08:02:43 AM »
If you are going beyond the squarebodies, any 2500HD will have a 14 bolt FF
1985 C30 Custom Deluxe Ext. cab 5.7L TH400 4.56 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Stewart G Griffin

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #6 on: June 13, 2018, 08:52:31 PM »
i have a 454 in my 91 crew. stew what are you wanting out of the tow vehicle? do you want something that can haul a lot of people or do you want that covered cargo space the burb offers? if i had the chance to do it again i would prob buy that 99 burb with the 6.5(think that was the year) that i looked at a few years ago. also why are you stuck on the 14 bolt?

1) To haul a lot of people AND be able to tow some weight.  A crewcab fits the people requirement, so i'm open to that as well.

2) i'm "stuck" on the 14 full float because i want to do it right;  We see it every weekend on the highway----a Toyota Sequoia, Tahoe, just about any 1/2 ton towing a car trailer or a tandem axle travel trailer.   They are kind of doing it, but not comfortably.   They can't keep up with traffic and don't seem to handle very well and you can tell the driver is struggling to keep it in the lane.   What fun is that?


Offline Stewart G Griffin

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #7 on: June 13, 2018, 08:53:39 PM »
If you are going beyond the squarebodies, any 2500HD will have a 14 bolt FF

i'm open to a newer truck if the right one comes along.

i think i read that the 2008-13 3/4 suburbans had the 14 bolt FF as well.

Offline ehjorten

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #8 on: June 14, 2018, 09:03:10 AM »
The 14 bolt is still in production, but in like 2001 it was replaced in most GM applications by the AAM 11.5"  Both axles are tough SOBs!
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline Stewart G Griffin

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #9 on: June 19, 2018, 12:56:09 AM »
i heard/read that all v-8 1/2 ton trucks 2014 and up have a 14 bolt SF?

Offline 75gmck25

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Re: 14 bolt SF vs. 14 bolt FF:
« Reply #10 on: June 24, 2018, 06:18:55 AM »
Most on-the-road towing breakdowns I've seen have been for overheating, flat tires, bearings going out, or broken hitch hardware.  Rear axle breakage is usually from encounters with mud, snow or other off-road abuse.  If a driver is struggling to keep a tow rig in the lane, its probably loaded wrong (too much weight in the back of the trailer), or the vehicle is too short compared to the trailer (big trailer with short SUV).

The 14 bolt FF is a great axle for heavy duty pulling/off-roading, but the SF in a 3/4 ton should be fine for most towing.

Bruce