Rear drum question - shoes rubbing backing plate

Fireball05 · Mar 22, 2013

Hey guys,
Another quick question I'm hoping the collective brainpower can help me with!

In the process of disassembling the rear end as part of the new suspension install, took the rear drums apart to replace the e-brake cables and found the shoes look to be rubbing heavily on the backing plates.

Check out photos below, is this normal? Something to be worried about? Everything seems to be working normally and just fine before disassembly, but those are some pretty serious grooves rubbed into the metal plates.

Thanks in advance for any help!

ImageUploadedByTapatalk1363960540.151900.jpg

ImageUploadedByTapatalk1363960553.887910.jpg

ImageUploadedByTapatalk1363960567.029437.jpg

Viperwolf1 · Mar 22, 2013

That's where the shoes contact the backing plate. Grooves can develop over time. If they're deep they could inhibit the action of the brakes. You can try to fill in the grooves with weld or just replace the plate. Make sure to put a dab of lithium grease on those pads when putting the brakes together.

Fireball05 · Mar 22, 2013

Viper, thanks for the quick reply. Is one of those options, welding versus new backing plates, preferred over the other? I'm not sure I've seen the backing plates sold separately by the vendors, although maybe since it is a common rear ends the local parts stores would sell them?

There are probably three or four of those grooves per side, the one I took the close-up photo of was the worst.

70_Steve · Mar 22, 2013

My backing plates were similarly grooved when I got my Bronco 17 years ago. I had a local welding shop fill in the grooves with weld (didn't have a welder at the time) and I ground them flat. Been working fine all this time, and I don't see any more grooves...

DirtDonk · Mar 22, 2013

With the ones I've worked on that had grooves (cars and trucks both) I was always able to either/or pound a little out, then file the surface flat. Sometimes it was shallow enough to just file the area smooth, lube it up and call it a day.
Luckily I've never run across one I had to weld, but I can see where that might be the only option.

Not sure if the backing plates are available as new anymore or not, but none of our suppliers has had them. Even though we sell full assemblies, even they are only available for the '76/'77 model year with their different setups.

Good luck. Can't tell by the pics, but maybe you'll get lucky and only have to dress them up a bit to get them into working order.

Paul

thegreatjustino · Mar 22, 2013

I just picked up a set that are grooved badly enough that I am going to have to weld and grind them. Just part of being a Bronco owner. Finding the correct backing plates is always a pain due to the four different rear ends Broncos came with over the years.

Steve83 · Mar 23, 2013

It's not "normal", but it's "common" on old drum brakes because so few people (owners AND pros) know that those points need to be cleaned & greased. Click this & read the caption:

matts460 · Mar 23, 2013

When we re-shoe rear brakes at work we put dabs of Antizeese on the backing plates to keep shoes from squeeking on the backing plates etc..also use it around the axle hub where the drums center to keep the drums from rusting together with the hub. Last a very long time! If you have a bigbearing 9inch housing all the muscle car venders sell complete 11" finned drum brake upgrades although the drums themselfs wouldnt fit (wrong bolt circle) but the backing plates and shoes would be the same im sure. I think you can get just the backing plates loaded with the new shoes and all new hardware.

Fireball05 · Mar 23, 2013

Guys - thanks for the helpful info. Only one groove per side is deep enough to require a bit of weld. We'll do that to each side, then flap disc them and the other groves to smooth it out. A little antisieze and reassemble everything. Got new wheel cylinders, spring kit and self-adjusters for each side. Shoes look very good, so should be good to go!

Took the axles out as well, new bearings and seals on order for those too. I'll call it a mini-rebuild. Had to resist the urge to buy heavy duty axles and a rear locker!

Steve83 · Mar 24, 2013

Antiseize is NOT a true lubricant. Use brake grease.

Fireball05 · Mar 24, 2013

Steve83 said:
Antiseize is NOT a true lubricant. Use brake grease.

Really? I was going to use the grey graphite anti-seize.

You think brake grease is better?

Incidentally, I am replacing the bearings and seals on the axles. Any difference or preference in what to go with? JBG sells TIMKEN bearings. Not sure what my local NAPA will stock, but will need to have them press the old ones off and new ones on.

Thanks again for the help!

matts460 · Mar 24, 2013

You should use what you feel comfortable with, have you ever had antizees let you down? It is used on Cat equipment nuts and bolts when things are repaired or replaced I know from experience and Cats see alot of mud/dirt right? LOL

Steve83 · Mar 24, 2013

Fireball05 said:
Really?

Did you look at the list of things it does on that label? It doesn't list any moving parts. It's made to prevent static parts from seizing, galling, or corroding - not to prevent moving parts from wearing. Even the graphite version.

Remember this is the English language - the one with the stupidest etymology, most-confusing construction, and longest list of blatant contradictions (especially in advertising & marketing). Convection ovens are designed to prevent convection; plunge pools are too small to plunge into; apartments are packed together; antifreeze was originally intended to prevent boiling; long-life antifreeze doesn't last as long as regular; and anti-seize lubricant doesn't lubricate; just for a FEW examples.

But it's your truck - I won't stop you from doing what you want to it.

Fireball05 · Mar 24, 2013

Well, it claims to be a lubricant and has graphite in it. My limited experience hasn't caused any problems, but I asked the question to learn more! I don't know it all, that's for sure, so happy to learn ways to improve, better products to use, etc.

That being said, if there a favorite brake grease I should be using?

patterdale · Mar 25, 2013

Anti seize is as stated for keeping things like bolts from locking up. On moving parts it is actually like lapping compound. I shot a crucial bearing full of it to prevent a fire in an OSB mill on the night shift. Grease when shot in ran out like water. I got a pretty good ass chewing because it forced them to schedule the bearing change before they wanted to do it. That was one hot bearing that was self destructing.

matts460 · Mar 25, 2013

The CRC brake greese is very good stuff just a bit pricey. Im sure wheel bearing greese would work too only using a small dab were the shoe touches the backing plate anyway. Just need somthing that wont wash right off and last along time Antizees seems to work well for that purpose same with CRC. Its kinda of a what do you have availible in your garage situation LOL Atleast the backing plates are back in good shape and should last another 40years right?

Steve83 · Mar 28, 2013

Anything that specifically says it's for brakes (better if it says disk) is OK. Anything that doesn't ISN'T. Wheel bearing grease that's rated for disk brake use is NOT brake grease. Everything in post #7 IS, and they're all available at most parts stores, dealerships, & online. Check Amazon & RockAuto - you might be surprised.

Fireball05 · Apr 8, 2013

Just wanted to close the loop on this... took the backing plates off, put a few spots of weld to fill some of the grooves, got out the flap disk, sanded everything smooth again, cleaned and painted and put everything back together with some grease. Hopefully everything is good to go!!!

Crawdad · May 9, 2013

Glad I saw this thread, great job on posting this must-see thread!

hc37180 · May 9, 2013

Crawdad said:
Glad I saw this thread, great job on posting this must-see thread!

Agreed, great topic & posts for answers. Guess what I will be checking from now on. ;D

Rear drum question - shoes rubbing backing plate

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