Late-model 14BFF with factory disc brakes??

[jonrpick]

For some reason it never occurred to me that GM had switched to rear discs on the 3/4 and 1-ton trucks. No idea why, it's just that I never see mention of anyone running a new 14BFF with factory discs in their older trucks.

Yesterday I was chatting with a friend and he mentioned how he'd gotten the wrong brake pads at a parts store. He'd gotten 3/4-ton pads for his 1/2-ton by accident. The parts man said, "well, you can keep the rear 3/4 pads, because they're the same as the 1/2-ton front pads."

*OK*

Yeah, I know the rears are usually smaller than the fronts on disc setups. But this made me think...

1) I was unaware of factory discs on a 14BFF
2) Why does everyone buy an older, drum-braked 14BFF and convert it rather than run a late-model with discs already installed (plus the benefit of newer parts all around)
3) Do the factory discs work well? Not just for stopping, but the ever-elusive 14BFF/disc parking brake setup???



TIA...

 

[1979jimmy350]

factory disk 14 bolts use the drum in hat for the parking brake, my guess is that the old style is so cheap compared to the newer ones that it is still cheaper to buy a old one and converted it then it would be to buy a newer axle

 

[jonrpick]

factory disk 14 bolts use the drum in hat for the parking brake, my guess is that the old style is so cheap compared to the newer ones that it is still cheaper to buy a old one and converted it then it would be to buy a newer axle

How well does the drum-in-hat setup work? I've heard of and seen this. Doesn't it use mini-brake shoes for the parking part?

I wonder if anyone has put late-model discs on an older 14BFF rather than deal with the Caddy calipers.

 

[1979jimmy350]

How well does the drum-in-hat setup work? I've heard of and seen this. Doesn't it use mini-brake shoes for the parking part?

I wonder if anyone has put late-model discs on an older 14BFF rather than deal with the Caddy calipers.

the drum in hat uses a small drum brake for the parking brake, it should be possible to put the newer style disk brake brackets on the older style 14 bolt ff

 

[muddybuddy]

also the older ones are direct bolt in, the new ones require u to move perches, and shock mounts

 

[Dogman12]

I did the disc swap and eldo calipers on my Jimmy, I forgot how to run the brake cables so i took a look under my d-max and to my surprise no drum in hat. It looked almost like my jimmy setup. Unless the drum in hat is different in 14ff it was not at all like the useless one on my 02 Tahoe 10 bolt. When i rotate my tires on my d-max i am going to take a closer look.

 

[4X4HIGH]

What you're talking about is not a 14ff, those are called the AAM axle and the ring gear is 11.5" not 10.5" like a 14ff. You cannot swap the rear disc/drum set-up to a 14ff either.

 

[jonrpick]

What you're talking about is not a 14ff, those are called the AAM axle and the ring gear is 11.5" not 10.5" like a 14ff. You cannot swap the rear disc/drum set-up to a 14ff either.

So did the 14BFF (10.5") ever come with factory discs??? Is the 14BFF still even offered?

 

[AJMBLAZER]

It evolved.

AAMCo was once a division of GM and did create the 12 bolt, 10 bolt, 14 bolt, etc back then. Since then it has remained GM's primary (might be only?) supplier of axles. In 2003 Dodge started using AAMCo axles under their 3/4 ton and 1 ton trucks instead of the half breed Danas they were running before.

The 10.5" 14FF many of us know so well evolved a bit into the modern 10.5" with disc brakes but also the same basic hard to mistake cover, 10.5" ring gear, and 30 spline axles. From this evolved 14FF came the "super 14FF" with the 11.5" ring gear and I'm fairly sure larger axleshafts with more splines. Variants of these axles are used by both GM and Dodge in their 3/4 ton and 1 ton trucks.

Is it the same axle as under my 1 ton? No. Is it related? Sure.
Is my '86 the same as a 2008 Duramax equipped K3500? No, but they're related.

 

[jonrpick]

It evolved.

AAMCo was once a division of GM and did create the 12 bolt, 10 bolt, 14 bolt, etc back then. Since then it has remained GM's primary (might be only?) supplier of axles. In 2003 Dodge started using AAMCo axles under their 3/4 ton and 1 ton trucks instead of the half breed Danas they were running before.

The 10.5" 14FF many of us know so well evolved a bit into the modern 10.5" with disc brakes but also the same basic hard to mistake cover, 10.5" ring gear, and 30 spline axles. From this evolved 14FF came the "super 14FF" with the 11.5" ring gear and I'm fairly sure larger axleshafts with more splines. Variants of these axles are used by both GM and Dodge in their 3/4 ton and 1 ton trucks.

Is it the same axle as under my 1 ton? No. Is it related? Sure.
Is my '86 the same as a 2008 Duramax equipped K3500? No, but they're related.

Yeah, I always knew AAM made the other GM axles (10b, 12b, 14b).

I guess now, I'm curious as to what the differences are between a 1988 14BFF and a 2008 14BFF (both 10.5").

For example, will the same gears/lockers/etc fit both?

 

[AJMBLAZER]

No. Know that one for sure...seen enough questions like this in the 4x4 mags to know that for sure. For a while they were pretty limited to the factory options but I do beleive that is changing.

 

[jonrpick]

No. Know that one for sure...seen enough questions like this in the 4x4 mags to know that for sure. For a while they were pretty limited to the factory options but I do beleive that is changing.

Hmm... I guess I'll have to do some digging to find out the specifics on both.

I have no plans to ever run tires that'll need a gearset that starts with a "5", so as long as it can accept the standard stuff (3.73, 4.10, 4.56) that may be an option for me.

Is a Detroit at least available?

In your opinion, what's the market value of an old vs. new 14BFF?? I mean, besides being newer, it seems the new ones are actually more limited, and thus less desirable.

 

[supersize75k5]

from all my reading and crawling around my truck,

my 3/4 ton disk brake rear axle shares much if not most of the older 14 bolt.

same ring and pinion
lockers
carrier bearing support and bearing



differences..


has dick brakes,
wider wms
different spring perch mounts
different flanges on the backing plates
different hubs to accomidate the different wms



so yes its the same, but no you cant bolt the backing plates on your older 14 bolt.

 

[jonrpick]

from all my reading and crawling around my truck,

my 3/4 ton disk brake rear axle shares much if not most of the older 14 bolt.

same ring and pinion
lockers
carrier bearing support and bearing



differences..


has dick brakes,
wider wms
different spring perch mounts
different flanges on the backing plates
different hubs to accomidate the different wms



so yes its the same, but no you cant bolt the backing plates on your older 14 bolt.

Ok... what about a direct axle swap? Other than moving the perches and shock mounts (same as you'd do with a 1-ton axle going in a K5).

How much wider do you think? Would it match the front?

 

[supersize75k5]

Yeah, I always knew AAM made the other GM axles (10b, 12b, 14b).

I guess now, I'm curious as to what the differences are between a 1988 14BFF and a 2008 14BFF (both 10.5").

For example, will the same gears/lockers/etc fit both?

outers would be different if one was drum and one was disk.

the aam with 11.5 only comes behind the dually or d-max equipped truck. I personally see it as the holy hell of boat anchors, I passed on one for damn near free. the thing is huge compared to my 14 bolt or Dana 70. Any for truck running just 35-40 inch tires I see it as just a plow being dragged to plant corn.

 

[AJMBLAZER]

I've been under the impression that no, you can't use the older guts in the newer 10.5's...but I could be wrong. It'd be years before I could afford a newer one so I really haven't paid to much attention to their inner workings.

That said...I'd go for an older 14FF if it were me. They're great big hunks of steel that work well. Even if they are earth anchors they're tough enough to take the abuse most folks give them and hey, they're damn cheap usually. Slap on some disc brakes (just waiting for my rear brakes to give me a reason to do this...so far they work great), slip a Detroit in, and call it good for less than any other comparable large axle would set you back.

There's a reason you see a lot of folks swapping 14FF's under other make trucks FAR more than Sterling/Visteon 10.25/10.5's, Dana 70's and 80's, etc. They're cheap and they work.

That said I have seen the occasional new model 14FF go for low prices in the trader mags and on some of the 4x4 websites around here. If you could get a traction adder for one better than the Gov-Bomb then it'd be a good choice provided the gears and price were right.

 

[supersize75k5]

Ok... what about a direct axle swap? Other than moving the perches and shock mounts (same as you'd do with a 1-ton axle going in a K5).

How much wider do you think? Would it match the front?

the older 14 bolts are 63 inches or so the newer ones if I measured right are around 67 inches. So yes it would then match the front but you would loose some turning radious from the rear tires tracking differently. For a 4x4 I like the front and rear the same.


an e-brake cable might need to be longer if you swap it in "no biggie" and depending on your driveshaft you may need a conversion joint .


as for price, the disk 10.5 ff with 4.10s is aout 400-500 average and is a pull yard if you are luckky 125-175

the high end places want 600-1200

I personally like the idea of buying a axle with 10k miles, huge disk set up, 4.10s and an e-brake for 500.00

no rebuilding it, no regearing it "if you desire 4.10s" no adding disk rakes and concernsing about an e-brake. no rebuilding brakes and bla bla bla

30 year old 14 bolt with 50k?100? 200k? maybe higher? full rebuild, parts, disk swap, more parts, leaks..

been there, done that and still broke a freaking axle that was 30 years old.

as gor the gov-bomb, I have no worries anytime soon, running one that is working and low mile is not the same as one form a service truck with 250k on it. Why would I spend 400-500 bucks plus tearing the axle apart to put a detroit in it.

 

[jonrpick]

the older 14 bolts are 63 inches or so the newer ones if I measured right are around 67 inches. So yes it would then match the front but you would loose some turning radious from the rear tires tracking differently. For a 4x4 I like the front and rear the same.


an e-brake cable might need to be longer if you swap it in "no biggie" and depending on your driveshaft you may need a conversion joint .


as for price, the disk 10.5 ff with 4.10s is aout 400-500 average and is a pull yard if you are luckky 125-175

the high end places want 600-1200

I personally like the idea of buying a axle with 10k miles, huge disk set up, 4.10s and an e-brake for 500.00

no rebuilding it, no regearing it "if you desire 4.10s" no adding disk rakes and concernsing about an e-brake. no rebuilding brakes and bla bla bla

30 year old 14 bolt with 50k?100? 200k? maybe higher? full rebuild, parts, disk swap, more parts, leaks..

been there, done that and still broke a freaking axle that was 30 years old.

as gor the gov-bomb, I have no worries anytime soon, running one that is working and low mile is not the same as one form a service truck with 250k on it. Why would I spend 400-500 bucks plus tearing the axle apart to put a detroit in it.

This is what I was trying to get at... Thanks. And yeah, why build an axle with a "usable core" if you can get the whole works and just move the perches?

And, concerning the Gov-Bomb... I know it's not a strong unit all around, but I thought it was mainly the 10-bolt G80 that sucked ballz... ??

 

[supersize75k5]

This is what I was trying to get at... Thanks. And yeah, why build an axle with a "usable core" if you can get the whole works and just move the perches?

And, concerning the Gov-Bomb... I know it's not a strong unit all around, but I thought it was mainly the 10-bolt G80 that sucked ballz... ??

thats my understanding as well,


mine seems to holding up to 25000 hellacious miles so far

 

[1979jimmy350]

I work for AAM so ill tell you the facts, the 10.5 is the same as in 1988 when it was updated from the original to add more ribs for increased cooling, it still uses the same gears and carrier as the old ones. The 11.5 is a totally new design that uses a one piece carrier like a 10 bolt. With the lack of after market lockers and its massive size its no wonder that they are not being used as much in offloading.