Something different, drum brake swaps - The 1947 - Present Chevrolet & GMC Truck Message Board Network

qksilver · 08-28-2010, 09:27 PM

I am trying to figure out a rear drum swap, seen kits for it but I have I think the right parts.

I have a bunch of 1/2 84-87 axles from stripping trucks. they all have the "heavy duty" brakes, 2 1/2 inch wide shoes.

I have two 67-72 trucks i am working on. They have 2 inch rear shoes. One is a 6 lug the other is 5 lug. Can I use the later model heavyduty backing plates and the wider shoes, hardware etc and the later model 5 lug drums on one and then some later model 6 lug 1/2 4x4 drums on the other.

It looks like it would work but i don't want to deal with pulling the axles and the gear fluid mess and smell if they won't work.

Anybody do this or have any advice or idea's? It would seem like a cheap mans way of improving the rear brakes with out the cost of a disc swap.

Thanks,
Steve

87chevy.com · 08-28-2010, 10:08 PM

man, on SpikeTV.. I seen an episode of trucks... they were rebuilding a 3/4 ton of some sort.... they swaped wheel cylinder from the 1 ton into the 3/4... they said it ws an improvement...

qksilver · 08-30-2010, 07:14 PM

Ttt

raycow · 08-31-2010, 12:08 PM

Pull a drum off of each of the axles. Measure from the drum mounting surface on the shaft flange to the backing plate where it bolts to the housing flange. I think this should show if you are going to have any major problems. While you are in there, you could also measure the bolt pattern on the backing plates, just to be on the safe side.

Ray

**Captainfab** · 09-01-2010, 12:51 AM

I have yet to do this, but I did the measurements years ago and those bigger brakes will interchange. The 8.5 10 bolts thru '87 that I've seen have the same backing plate mounting pattern as the truck 12 bolts. The '88 and up 8.5 10 bolts have a different backing plate mounting pattern.

qksilver · 09-04-2010, 02:32 AM

it looked like it would work, I didn't have a 4x4 drum to check

thanks

08-28-2010, 09:27 PM	#1
qksilver Senior Member Join Date: Dec 2004 Location: Southern Pines NC Posts: 3,853	Something different, drum brake swaps I am trying to figure out a rear drum swap, seen kits for it but I have I think the right parts. I have a bunch of 1/2 84-87 axles from stripping trucks. they all have the "heavy duty" brakes, 2 1/2 inch wide shoes. I have two 67-72 trucks i am working on. They have 2 inch rear shoes. One is a 6 lug the other is 5 lug. Can I use the later model heavyduty backing plates and the wider shoes, hardware etc and the later model 5 lug drums on one and then some later model 6 lug 1/2 4x4 drums on the other. It looks like it would work but i don't want to deal with pulling the axles and the gear fluid mess and smell if they won't work. Anybody do this or have any advice or idea's? It would seem like a cheap mans way of improving the rear brakes with out the cost of a disc swap. Thanks, Steve

08-28-2010, 10:08 PM	#2
87chevy.com BMW & ASE Master Certified Join Date: Feb 2004 Location: Houston, Texas Posts: 1,262	Re: Something different, drum brake swaps man, on SpikeTV.. I seen an episode of trucks... they were rebuilding a 3/4 ton of some sort.... they swaped wheel cylinder from the 1 ton into the 3/4... they said it ws an improvement... __________________ 1987 Silverado - L83 5.3 w/ 6L80e ,A/C,P/W,P/L,TILT, HID projectors, Wilwood C-10 Pro Spindles w/ 2018 silverado front brakes & C-5 Corvette Rear Disc Brakes 1999 BMW 528i - 5.7 LS1 w/ 4l60e, Ford 8.8 IRS w31 spline posi & FX-r projector retrofit New project: 2006 BMW x5 6cyl AWD to L83 6l80e 4wd to 2WD / RWD A poor man buy's it twice finally got my domain name back, 87chevy.com.... site rework in progress

08-30-2010, 07:14 PM	#3
qksilver Senior Member Join Date: Dec 2004 Location: Southern Pines NC Posts: 3,853	Re: Something different, drum brake swaps Ttt

08-31-2010, 12:08 PM	#4
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: Something different, drum brake swaps Pull a drum off of each of the axles. Measure from the drum mounting surface on the shaft flange to the backing plate where it bolts to the housing flange. I think this should show if you are going to have any major problems. While you are in there, you could also measure the bolt pattern on the backing plates, just to be on the safe side. Ray

09-01-2010, 12:51 AM	#5
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,247	Re: Something different, drum brake swaps I have yet to do this, but I did the measurements years ago and those bigger brakes will interchange. The 8.5 10 bolts thru '87 that I've seen have the same backing plate mounting pattern as the truck 12 bolts. The '88 and up 8.5 10 bolts have a different backing plate mounting pattern. __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

09-04-2010, 02:32 AM	#6
qksilver Senior Member Join Date: Dec 2004 Location: Southern Pines NC Posts: 3,853	Re: Something different, drum brake swaps it looked like it would work, I didn't have a 4x4 drum to check thanks



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