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kevinr1970 · 01-10-2011, 05:21 PM

I had a chance to get some stuff done on the trucks this weekend.

I was talking to a friend of mine and he said to make sure that the backing plates were the same diameter.
While doing that I noticed that althought they are roughly the same diameter, they are shaped different.
The 2wd (5-lug) backing plate is "flat" for lack of a better word while the 4x4 (6-lug) backing plate has an offset to it; they are offset to the inside, towards the diff.

The 4x4 brake shoes are about 2-3/4" wide while the 2wd shoes are about 2" wide.
The drums are about the same width difference also AND this appears to be about the some amount as the offset of the backing plates.

I am pretty sure that there are at least two different size rear brake shoes; 2" light duty and 2-3/4" heavy duty.
We are theorizing that the axles are the same width 2wd vs. 4x4, no matter what brakes are there and that I need to order new drums and shoes for the 2-3/4" brakes and everything should be hunky-doory.

Anyone confirm or refute this?

01-10-2011, 05:21 PM	#12
kevinr1970 Senior Member Join Date: Aug 2004 Location: Everett, WA Posts: 2,316	Re: 1/2 ton 4x4 vs 2wd rear-end I had a chance to get some stuff done on the trucks this weekend. I was talking to a friend of mine and he said to make sure that the backing plates were the same diameter. While doing that I noticed that althought they are roughly the same diameter, they are shaped different. The 2wd (5-lug) backing plate is "flat" for lack of a better word while the 4x4 (6-lug) backing plate has an offset to it; they are offset to the inside, towards the diff. The 4x4 brake shoes are about 2-3/4" wide while the 2wd shoes are about 2" wide. The drums are about the same width difference also AND this appears to be about the some amount as the offset of the backing plates. I am pretty sure that there are at least two different size rear brake shoes; 2" light duty and 2-3/4" heavy duty. We are theorizing that the axles are the same width 2wd vs. 4x4, no matter what brakes are there and that I need to order new drums and shoes for the 2-3/4" brakes and everything should be hunky-doory. Anyone confirm or refute this? __________________ 2009 Honda Fit CfC (bsf 44.9 mpg) 2000 Tahoe Limited 1991 GMC CrewCab Dually 2wd, will end up swb, not dually and replace CCswb below 1991 GMC CrewCab Dually 4x4, just going to fix things up for now 1982/1989 K5/GMC Jimmy 2wd 1987 GMC 1/2 ton swb 2wd Crew (sold)