'71 Suburban 4wd brake drums made of unobtanium?

[riceranch]

Hi guys and gals,
I've been looking around here for answers to every other question I had for the last couple months since picking up this beast of a truck. Now I'm at the point where she's up on blocks in the garage and I seem to be running out of options for finding/repairing rear drums. Autozone/O'Reillys/Car Quest had nothing but Napa had a drum for a 3/4 ton truck so I had one shipped out here and picked it up today. It looks close but I won't know whether it works until… i can get the old drums apart.

So my question is: Aside from finding a real mechanic in the area- not just a parts replacement specialist, are there any tips and tricks you guys would share with me regarding how to separate the drums from the spacers, how to drift out the wheel studs in my garage without a bearing press and what I'm looking for as these beasts come apart?

Thanks in advance for any and all help,
Mark-Anthony

[vectorit]

I've always had that stuff swapped at anyplace that does brakes.

I suppose one could do that stuff with out a press.
But for a few bucks to pay a guy for his time on a press, to avoid hours of beating on a brake drum in the driveway?

Save yourself the head aches and take the new and old drums to a brake shop, I am betting that you will be glad that you did.

[CrewCab59]

Your going to need a Hammer and a punch , also a need a section of wood underneath to keep the hub from damage.

If your going to try to reuse the studs place the nut on the stud before you start driving the stud out, this will help keep the stud from mushrooming out and the starting threads won't be damaged. Once all the studs are out the hub will separate from the drum maybe little rust built up.

Once the studs are out you need to clean them and look them over to make sure there still good. You don't want any ( pits , pulled threads ) . The reinstall is about the same but you'll want a 2lb hammer and a bigger punch ( piston pin , cold rolled bar so you have more surface to push the stud back in.

Hope the helps.

[Bigdav160]

It might be easier to convert to disc brakes than to find those drums (new).

I used a hydraulic press to remove the studs and separate the drums from the hub

[72 K20 Fleetside 4x4]

Have you tried using a little heat to help with the extraction?

[riceranch]

Thank you all,
I suppose I got discouraged after last weeks "we can't get those pushrods for the slave cylinders" hunt and this weeks "we can't get those drums" combined with "that'll probably be 1200 bucks" to put those together for you" hunt.

vectorit: I'm looking for that shop and I know I'll find it or a neighbor will see me working on it and offer help eventually. I was just turned off after getting sent to two shops by the guys at NAPA who wanted to charge me close to what I paid for the truck. I may end up with a hydraulic press in the garage since the quotes I got for ball-joint replacement were plain nuts as well.

CrewCab59: Thanks for the reminder, I have all the parts bathed in penetrating oil and will be giving them a nudge tomorrow. Now if I could just figure out what my boys did with my 2lb sledge

72 K20 Fleetside: Heat will not be ignored. My wife wants me to make some creme brûlée so the torch has to get broken out anyway

Bigdav160: That's what I'm wondering. I may end up going that way if the drum I just got won't work. My mindset was to do the best I could with what I have so I bought parts that I needed based on what I could see… I just didn't figure on experiencing the resistance to getting the pieces and parts I need. Perhaps this is more of a lesson for me as I keep telling my boys to be patient, do what you know how to do and ask questions even if the first answer you get is that it can't be done.

Thanks again guys,
Mark-Anthony

[riceranch]

Hey guys, it's me again…

I started looking into rear disc brake conversions or looking into swapping 14 bolt rear-end brakes onto my Eaton axle, it made me think. Perhaps someone along the way was thinking the same thing and used drums that are not specific to the Chevy hence why every set I've picked up doesn't fit.

Can you guys think of a way/site to "reverse" look-up drums by dimension? My searches have given me Borg Warner and Centric parts but their dimensions are still 1/4-1/2" too deep when compared to what I have.

Any help, as always is appreciated.
MA

[WhiteWhale]

Are 72 3/4 ton suburban drums different than 71? The drums on my 3/4 ton sub are much bigger and finned and are available at Oreily


2 year limited warranty
Outside Diameter (In): 13.74 Inch
Overall Height (In): 5.35 Inch
Bolt Pattern: 8 On 6-1/2 Inch

Part # : 2079DGS | Line: BBR


edit: I just checked the parts manual and indeed it is a one year only drum. There was another solution here which might help

http://67-72chevytrucks.com/vboard/s...ad.php?t=67518

[riceranch]

Thanks WhiteWhale I took a quick look at the link you posted and it confirms what I'm going through. I came across the same issue with NAPA, they had drums for a '71 K20 truck, nothing for the Suburban but that depth/height of 5.35" meant I would need to pick up everything from the backing plate out to make it work.

I don't mean to be stubborn and may well swap parts from the plate out, but I'm also not wanting to accept defeat just yet as I have boxes of parts gathered and no more "spare" cash to play with.

[04sshd]

that drum looks like a GM Corporate rear end drum brake. They had a few different types back in the day.

[vectorit]

If your heart is set on keeping the Eaton axle, as many other guys including me. Then check out this thread that "JBCLASSIX" put together, it may answer a lot of your questions putting you back on track.

http://67-72chevytrucks.com/vboard/s...d.php?t=536119

[justcuz]

Chris you beat me to it.
For those that want to keep the parking brake and drums, the 14 bolt conversion is the most cost effective way.
The Eaton rear axles are so old now that most parts counter guys don't know anything about them and usually their parts books are not old enough or the information is wrong.
Use the bearing numbers in this thread and swap to the 73 and up 13" brakes.
For daily use you will probably never break a 17 spline axle but if you do conversion to the 30 spline 73 and up axles is not real difficult.
Its all covered in this thread mentioned above.

[WhiteWhale]

Im trying everything possible to keep the eaton under my burb but want a detroit locker bad. Ive read several threads about putting in the 14 bolt axles and detroit but have seen some recommending removing the 1/4 inch from the axle and others saying its not necessary.

Do I have to machine the axles or not?

[riceranch]

Thanks again guys… I have one more return stop on Monday to the 100 year old driveline and brake shop locally, so we can call his contact in Oregon who relines odd and unobtainable shoes. After that and even if we can make something work, it looks like wisdom will prevail and I'll be doing the 73-87 swap/Dana 60 (thank God there are a few locally)…will just have to make sure the gear ratios are the same from the front to the rear.

I truly appreciate everyone's time and willingness to share knowledge.

[60sIron]

Originally Posted by vectorit

If your heart is set on keeping the Eaton axle, as many other guys including me. Then check out this thread that "JBCLASSIX" put together, it may answer a lot of your questions putting you back on track.

http://67-72chevytrucks.com/vboard/s...d.php?t=536119

Great reference as the rear drums on my Burb are toast also. I couldn't find them 12 years ago. So I put them back on...... The issue I have with the drum conversion to the 14 bolt drums is it appears to move the wheels out an inch on each side. Does anyone know if the disc conversion changes the track from stock? I like my wheels siting where they are.

[LockDoc]

-
Did you ever consider having the drums turned? Looks like there is still a lot of meat on them. I have had two sets done without issue.

LockDoc