2000 10 bolt rear disks on 86

[dyeager535]

Ain't gonna happen easily : (
Had the chance to crawl under one last night, and measure the axle flange vs my '86 10 bolt. 2000 has a 3.5"x3.5" 4 bolt pattern, the '86 has a 3"x3.5" Axle flange is rotated 45 degrees, but that probably wouldn't matter much.

Looks like plenty of clearance to run a 15" wheel though, if you wished. E-brake comes off the rear of the backing plate, so it loops forward over the axle.

Appears you couldn't just re-drill the backing plate, (bolt holes would be too close together) but perhaps with some grinding of the edge of the axle flange for the slightly different bolt pattern, and a plate custom made to bolt to the back of the stock '86 flange, plus two additional holes in the "adapter plate" for the wider disk brake backing plate bolt pattern, it would bolt up. Sounds like a lot of work though, unless some company mass produced them. On top of that, the e-brake cable would then point at the ground, or straight up, which might cause some problems as well.

Perhaps some of the trucks 88-up were still using the same flange? Anyone know when rear disks were first offered? If GM made the disks for the "earlier" flange pattern, it might be a direct swap. I did notice that the "triangles" on the lower edge of the diff housing on the newer trucks, has been changed, but that probably doesn't indicate anything.

Dorian
My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
Why insist on counting when the ring gear has the tooth counts stamped in?

 

[86blazerk5]

Why dont you just wait until you see a wrecked 2000 in a yaerd, and pull its entire rear end, then all you have to do is cut and reweld the spring perches, and the shock mounts. if you are lucky, maybe you could even find a 2500 and get a 14 bolt sf with discs... thats what I was thinking of doing in a few years. Oh, and by the way, rear disc brakes are only available in the new style chevy trucks from the factory. They first ones were out in late '99, then you had 2000, 2001, and 2002 are out already... Good luck.
Ike

Spreading The K5 Gospel!

 

[dyeager535]

My friend mentioned this as well, and I had to counter with: you have to likely move spring and shock mounts. Likely change gear ratio front or back. Would be worth it for a 14 bolt, but a 10 bolt, no thanks Then again, for my needs, 10 bolt is fine.

Dorian
My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
Why insist on counting when the ring gear has the tooth counts stamped in?

 

[88K5Jimmy]

What about track width?? What would be the measurements for the late model truck versus a K5??

 

[dyeager535]

Yet another reason not to do the swap. Didn't measure, but I guess if it was up to 3" wider than what we have now, it would look ok. Probably would be cheaper to use an entire 14 bolt w/disks from the get go than to buy the 14 b, then add disks to it, but again, the overall width might mess that idea up. Besides, these things are none to common in the wrecking yards I frequent.

Dorian
My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
Why insist on counting when the ring gear has the tooth counts stamped in?

 

[Sparky87k5]

My 98 GMC Jimmy with towing option has rear disc brakes and 3.73's in the 10 bolt. Been looking it over real close but the wife said stay away from it, "runs fine like it is", "go work on your own truck". You married guys know what I mean!

87 K5, 427BBC,D60 & 14BFF, NV4500, NP208, TSM disc's,

 

[shoeless]

Cadillac put rear discs on '76-'78 sedan de villes? Not sure exactly which model, but it had a 10 bolt rear with discs. I found one at a pick-a-part in Houston. I was going to pull the setup and use it on one of my vehicles, but I didn't have socket to pull the calipers off to get to the backing plates. I came back a couple days later and they had already pulled it to have it crushed.
The setup should work on a k5 10b, but you will need to find a different length parking brake cable, and 6-lug rotors.

Shoeless
'88 K5

 

[dyeager535]

Those Cadi calipers ARE self adjusting correct? I guess some Firebirds that vintage also got discs on the 10 bolts, but apparently they aren't self adjusting??? (heresay, but I don't doubt this source very often)

Dorian
My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
Why insist on counting when the ring gear has the tooth counts stamped in?

 

[86blazerk5]

i cant imagin the rear axle being that much diferent in width in a new truck verses the old truck. it may be a lattle wider, but remember, you have 3 inches to play with hear. Plus, it depends on what gears you already have in your K5. I was thinking in a few years, when newer wrecked trucks become more common, that I may go serching for a 14 sf with discs out of a 2500, or 3500 for cheap. I would have to swap its gears anyway, becuase i am running 4.56s, and i dont think that is a factory gear.
Ike

Spreading The K5 Gospel!

 

[EZdoesit]

I would be very interested to know if the new brakes could be swapped over too. I have access to a 99 and a 2001 rearend that were both replaced because the axle tubes were bent in accidents but the brakes are still all there and are undamaged.

Hmm, there has to be some way to make them work, they are pretty good sized brakes too, haven't measured them but they must be around 11" rotors or so.

 

[pcorssmit]

The Caddy rear disks were on Eldorados, about those years. These are the ones I (and many others) use on 14 bolt disk conversions. They are physically the same size as 1/2 and 3/4 ton front calipers, and fit on the backing plates. They are adjusted by using the e-brake, there is a ratchet mechanism inside the piston.

Pete

'83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
'97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd