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C3500 Rear Axle (floater) ? drum brake to disk brake? help please

This is a discussion on C3500 Rear Axle (floater) ? drum brake to disk brake? help please within the Technical / Maintenance forums, part of the General Discussion category; Hello! First post and i'd like to say this place looks to have tons of info, but my searches did ...

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    C3500 Rear Axle (floater) ? drum brake to disk brake? help please


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    Hello! First post and i'd like to say this place looks to have tons of info, but my searches did not yield any answers. I have a 1997 C3500 4 door dually that i haul a ~4000-5000lb cab over camper with. It has about 45,000mi on it so far. I just replaced the rear drum shoes about 1000-1500mi ago, but i now have oil leaking out of the drum due to failed seals. I'm not sure which axle it is so if anybody knows that will help me out a lot. I think it might be a dana 60, but really dont know. I know its a full floater. Here are a few pictures of the axle if that helps



    I always downshift on the hills to minimize the brake use, but think i still overheated the giant drums coming back from yosemite last weekend. I also have what looks to be an oil leak where the driveshaft goes into the dif. I am wondering if anybody knows a easy way to get some real HD disk brakes on there. How well do the drums hold up normally to heavy heat? Do you think it was just a bad seal and if i get it replaced it should be fine for a long time? Are there special seals made for high heat? I was thinking about a full axle swap with disk brakes from a newer truck, or a full rebuild with all new seals and bearings. I plan on keeping this truck forever, and it will live most of its life under the heavy camper. I added airbags, and a sway bar, but i sheared the bolts off the swaybar sometime not too long ago (when it rains it pours). If i could get disk brakes on it for less than 2K i would really consider it. My rear needs to take probably more than 50% of the braking due to the duallys grip and the heavy camper on them. Its relatively easy to overload the front brakes as i found out before i replaced my rear drums and found oil in both of them from bad seals. Once they were rebuilt the braking performance was WAY better. Sorry for the long post, but hopefully some of you experts read this far and can help me out with some pointers.
    Thanks!
    Joe
    1997 C3500, 2wd 4door long bed dually, with a big heavy camper. more info on my truck and mods

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    After more research it looks like a GM14 bolt full floater.

    I found these brakes too. http://www.tsmmfg.com/2830.htm Do you guys think these will be enough brakes? The drums have WAY more shoe to drum surface area, like 5x more!
    1997 C3500, 2wd 4door long bed dually, with a big heavy camper. more info on my truck and mods

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    Joe,
    Food for thought on this... I worked for a Fire District where we had a K3500 with rear disk brakes as an Ambulance. It was right at 12,000lbs loaded. It ATE rear brakes, even with the Allison and Duramax. When I say ATE, I mean, 5-8,000 miles on a set of brakes, and at that time, requiring rotor replacement in the rear. Now, you won't be loaded all the time like we were, but, they do have issues with wear.
    A couple of other items... If you are using the truck both loaded, and unloaded (camper is off)... Be careful if you bias the brakes too heavily toward the rear. Under hard braking, the rear may have a tendency to lock up.
    IMHO I think that the rear disk would take more heat, as opposed to the drum.
    Lastly, I would consider the rear swap, making sure to swap out the master cylinder, as they are different for disk instead of drum.
    Paul

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    I think the discs would be much more resistant to fade as they would shed heat more quickly. I say go for the swap.
    1999 2 Door Tahoe 4x4 w/ 14 Bolt SF & TruTrac. All kinds of upgrades, SOLD 1/2012
    2008 Silverado 1500 Z71, leveling kit, exhaust, SOLD 9/2014
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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    That is for sure a 10.5" 14bolt FF axle. Sounds like it needs new seals in the back of the FF hubs. If you are having trouble with those seals failing then it might be time for a set of speedi-sleeves for the spindle surface.

    As for drums to disks, make sure you get a good kit, with loarge calipers and thick rotors. If you want an Ebrake then i would suggest a setup like the newer drum in hat design.
    2000 Tahoe Z71, 14bFF 6 lug, 241 swap, bumpers, sliders.
    1988 K5, 350/700R/241 locked 10B, welded 12B, 35's, half doors.

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    Thanks guys! The truck will have the camper on nearly all the time. This is because i don't have a good storage area for the camper that wont block access to my 4 post lift, and that the camper has only about 1.5" of total clearance between the wheel wells so backing into it is tricky with 3/4" on each side to play with. I'll probably add a proportioning valve so i don't do 180s if i remove the camper. I have never like drums and swapped the drums out on my jeep already. I am just worried that the giant shoes are about 4x6" instead of the wimpy little brake pads that are about 2x4", but at least the rotor is 12.75". The drums are freak'n huge and probably weigh at least 50lb each and have WAY more contact area. I guess that the disks should have similar stopping power?? They will shed heat much better for sure. The drums take forever to cool down and are pretty much buried in the wheels so the get very little air flow. I'm not real concerned with wear because i only drive a few thousand miles a year on camping/ climbing trips. I have a jeep and a mustang to drive around town. Is a new master cylinder really necessary for the disks? Anybody have any info on which one i would need?
    1997 C3500, 2wd 4door long bed dually, with a big heavy camper. more info on my truck and mods

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    Quote Originally Posted by chevytaHOE5674
    That is for sure a 10.5" 14bolt FF axle. Sounds like it needs new seals in the back of the FF hubs. If you are having trouble with those seals failing then it might be time for a set of speedi-sleeves for the spindle surface.

    As for drums to disks, make sure you get a good kit, with loarge calipers and thick rotors. If you want an Ebrake then i would suggest a setup like the newer drum in hat design.
    thanks for the info on the axle. I think i may be cooking the seals and thats why they are failing. I encounter many steep hills and even engine braking in 2nd still requires some brake force to keep my speed down. (damn gas engines with no jake brake!) Got any tips on finding a good kit with the internal drum parking brakes? I've been searching the net for hours and the only decent kit for DRW is the one in the link above. It looks pretty beefy, but does not have the drum parking brakes.
    Last edited by jgorm; 10-14-2008 at 12:32 PM.
    1997 C3500, 2wd 4door long bed dually, with a big heavy camper. more info on my truck and mods

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    Your best bet may be to look into a setup off a newer body style truck. Possible swap just the brakes, or an axle swap.
    2000 Tahoe Z71, 14bFF 6 lug, 241 swap, bumpers, sliders.
    1988 K5, 350/700R/241 locked 10B, welded 12B, 35's, half doors.

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    Quote Originally Posted by chevytaHOE5674
    Your best bet may be to look into a setup off a newer body style truck. Possible swap just the brakes, or an axle swap.
    I checked to see what the new 3500HDs run and they use 13" rotors with twin piston calipers. This kit is a 12.75" rotor with a single piston caliper (61mm single piston with the ebrake atachment) They have the option to run an additional 80mm single piston for a dual caliper setup. (would look pretty cool!) The guy said some tow truck guys are loving the dual caliper setup. I figure this would be easier and cheaper than a axle swap. (~$1300). Any thoughts?
    1997 C3500, 2wd 4door long bed dually, with a big heavy camper. more info on my truck and mods

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    Does anybody know if they used the GM14 bolt on the newer HD trucks with disk brakes? I could do a junkyard swap if they do for much cheaper.
    1997 C3500, 2wd 4door long bed dually, with a big heavy camper. more info on my truck and mods

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    The 14 bolt is still around today. You might be able to swap the whole thing over, but I believe you'd have to move the spring perches. I think the overall width is still the same or damn close.
    1999 2 Door Tahoe 4x4 w/ 14 Bolt SF & TruTrac. All kinds of upgrades, SOLD 1/2012
    2008 Silverado 1500 Z71, leveling kit, exhaust, SOLD 9/2014
    2014 Silverado 1500 Z71, stock for now

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    I'd rather do a brake swap if they will fit. An axle swap is a lot of work!
    1997 C3500, 2wd 4door long bed dually, with a big heavy camper. more info on my truck and mods

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    Re: C3500 Rear Axle (floater) ? drum brake to disk brake? help please

    I doubt you'll be able to do a brake swap using factory parts. The flange to which the brakes attach will be in the wrong position. Plus, you have a 1988+ axle, and most of the aftermarket kits are for earlier axles. It would be far easier to swap the entire axle. Having said that, I'd take another look at your existing brakes. It sounds like something is wrong with them, to me. Take a drive to the store.... do your errands. When you stop feel how hot the drums are getting. If they are getting hot, your shoes are hanging up, or the adjusters are too tight.... something isn't right.
    454cid
    1999 K3500 RCLB

 

 

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