1Matthias
Newbie
So to make a long story short, the rear axle on the FrankenTruck is a little less than pleased at the moment: seems the previous owners ignored a substantial pinion seal leak, ran it low, and now it's on the way out. I *could* rebuild it...but there's a pick and pull 6.0 GMT800 2500HD near me that has a G80 14 bolt FF in the ratio I need, with disk rear brakes that seems a tempting upgrade. Now, to summarize what I've learned and my questions:
Minor concerns/findings:
1 The spring perches will need to be cut off and rewelded moved slightly over, ditto(?) for the shock mounts. This doesn't scare me, no stranger to welding and fabrication.
2 The track width will be slightly different. Again, not particularly worried: I do have room under the utility bed for the added width, and it might help fill out the arches a bit better and make tire work feel less like spelunking.
3 Parking brake cables will need to be fabbed/mashed together. Again, not worried about doing this, seems an easy enough task.
4 The yokes are different on the GMT400 and GMT800 FF14 bolts - again, not an issue as I can either swap the ujoint in the truck, or swap the yoke on the axle.
Now, the big concerns...
1 Brake proportioning. I wish to retain ABS on this truck for a variety of reasons, so a simple delete is out of the question. I have the 1995+ style ABS unit with the lines coming in the rear (facing the firewall) style ABS block. Supposedly you can remove the proportioning/residual valve from the combination block as referenced here https://www.gmt400.com/threads/what-proportion-valve-to-use.52803/post-1160468 to convert it for disk/disk use. That post also referenced a disk/disk combination valve: does anyone know of a part number for this disk/disk combination valve?
2 Master cylinder selection. This truck has hydroboost as it was a 3500 originally/mechanically. Would I simply need to swap to a NBS/GMT400 disk/disk hydroboost master cylinder, or is there more nuance to it than that? I do not have quick uptake front calipers thanks to being a 1 ton, so that is not a concern.
I will be towing rather heavy loads regularly with this truck and live in a somewhat hilly location...so the added stopping power of disks would be greatly appreciated.
I greatly appreciate any and all help in advance, and if there's anything I've neglected to consider please let me know!
Minor concerns/findings:
1 The spring perches will need to be cut off and rewelded moved slightly over, ditto(?) for the shock mounts. This doesn't scare me, no stranger to welding and fabrication.
2 The track width will be slightly different. Again, not particularly worried: I do have room under the utility bed for the added width, and it might help fill out the arches a bit better and make tire work feel less like spelunking.
3 Parking brake cables will need to be fabbed/mashed together. Again, not worried about doing this, seems an easy enough task.
4 The yokes are different on the GMT400 and GMT800 FF14 bolts - again, not an issue as I can either swap the ujoint in the truck, or swap the yoke on the axle.
Now, the big concerns...
1 Brake proportioning. I wish to retain ABS on this truck for a variety of reasons, so a simple delete is out of the question. I have the 1995+ style ABS unit with the lines coming in the rear (facing the firewall) style ABS block. Supposedly you can remove the proportioning/residual valve from the combination block as referenced here https://www.gmt400.com/threads/what-proportion-valve-to-use.52803/post-1160468 to convert it for disk/disk use. That post also referenced a disk/disk combination valve: does anyone know of a part number for this disk/disk combination valve?
2 Master cylinder selection. This truck has hydroboost as it was a 3500 originally/mechanically. Would I simply need to swap to a NBS/GMT400 disk/disk hydroboost master cylinder, or is there more nuance to it than that? I do not have quick uptake front calipers thanks to being a 1 ton, so that is not a concern.
I will be towing rather heavy loads regularly with this truck and live in a somewhat hilly location...so the added stopping power of disks would be greatly appreciated.
I greatly appreciate any and all help in advance, and if there's anything I've neglected to consider please let me know!