Anyone upgraded a full float 14 bolt to disc brakes?

[454cid]

I don't think it needed to be stronger at the hub, at least not early in the GMT800 run. If you think about it, there was about a 100 ft/lb jump in torque with the updated power trains which an increase in only R&P can help with. That said, the 11.5 gives up the pinion support that the 10.5 has and the 10.5 is pretty well bulletproof as it is. So I'm with you, no real point in the 11.5. But I also don't see the point in swapping to an improperly engineered rear disc setup when the drums have more than enough stopping power and a highly effective parking brake.

Oh yeah, I forgot about the pinion support.

I have not seen the GMT-800 10.5 with disc brakes up close, but that's what I'd look into if I really wanted rear discs on a GMT-400. Mounts, need to be moved, but I'm unsure of other changes that may have been done to the axle.

 

[454cid]

The one 11.5" axle I might consider would be what was referred to as the "wide track". I believe it went under things like cab and chassis vans that became things like ambulances. Their axle tubes are super beefy. Greater diameter, and much thicker, than what pickups got. They were a narrow dually axle, but called "wide" because of the dually footprint, I guess.

 

[Jrgunn5150]

Oh yeah, I forgot about the pinion support.

I have not seen the GMT-800 10.5 with disc brakes up close, but that's what I'd look into if I really wanted rear discs on a GMT-400. Mounts, need to be moved, but I'm unsure of other changes that may have been done to the axle.

I have one in my driveway to go in.

Leaf mounts, shock mounts, rubber line, brake hookup.

If you can weld, a weekend swap, if not, Lugnut it is lol.

 

[joeblow867]

Disabling the park brake is nuts.

Here in the rust belt they never work anyway.

I converted it to rear disc brakes, and I got the calipers with the e-brakes designed into them, and I can tell you, that they are a total nightmare.

The e-brake is a nightmare or the entire rear disc setup is a nightmare?

 

[Jrgunn5150]

The e-brake is a nightmare or the entire rear disc setup is a nightmare?

The El Dorado style calipers with Ebrakes are a challenge to keep adjusted.

They were designed in the mid 70's, they're not awesome. I only ever used them one time, then never bothered again.

 

[Supercharged111]

Here in the rust belt they never work anyway.



The e-brake is a nightmare or the entire rear disc setup is a nightmare?

I live in the rust belt and my stuff works. But more to your question, the entire setup sucks.

 

[TexasTahoe]

Here in the rust belt they never work anyway.



The e-brake is a nightmare or the entire rear disc setup is a nightmare?

Using the Eldorado capliers were the headache. Not the entire disc break conversion. The problem is, that the cable pull capcity is not enough to engage the calipers. No amount of cable adjustment allowed the calipers to close enough to prevent the wheels from turning. Switching to the t-case e-brake solved all that. As for the disc brake conversion, that aspect, which I got from Kert and DIY4X, worked perfectly! I have just leared that Kert closed up shop many years ago. Sad loss.

 

[cj8scrambld]

The problem is, that the cable pull capcity is not enough to engage the calipers. No amount of cable adjustment allowed the calipers to close enough to prevent the wheels from turning.

Not sure, but based on this info right here....YOU never adjusted them proper out of the box. They need to be adjusted installed on the vehicle AND adjusted BEFORE they are bled. If you try to adjust them after they are bled they are a bloody nightmare and you'll never get them right.
AND, there should ONLY be about an 1/8" play/gap in the brake lever arm and the stop when adjusted proper...so very minimal cable pull needed.
AND, once properly adjusted and functioning they have to be used ALL THE TIME to have them STAY in adjustment.

I went through that with the Eldo calipers on my 14ff in my Jeep but now they are fine...following the above . There are VERY explicit directions on setting them up.

But you're right, they are a pain compared to a 14ff with OEM disk brakes which uses drum in hat.....so apples to oranges in that regard.

 

[Sean Buick 76]

I wonder what rear end my 2012 GMC 2500HD has? I thought it was a 14 bolt full floater. It has nice big rear disks that work really well! 5 years and no issues.

 

[Jrgunn5150]

I wonder what rear end my 2012 GMC 2500HD has? I thought it was a 14 bolt full floater. It has nice big rear disks that work really well! 5 years and no issues.

If it has a bolt on yoke it's a Aam 10.5, if not it's an Aam 11.5