HO 52/ HO 72 question
 

I have 3 different rearends to choose from for my dually.

1) 72 dually ho72 with 4.11 ratio
2) 68 dually ho72 with 5 something ratio
3) 72 3/4 ton with ho52 and 4.11 ratio.

It's my understanding that the center sections will interchange freely between the ho52 and ho72 rears correct?

Do I just pull the axles then drop the center section out as a unit?

Will there be any housing differences between the 68 and the 72 dually rear housings?

Will I be able to find service parts to rebuild the rear brakes to good condition?

The only difference between the 3/4 and 1 ton rear ends is that the 3/4 ton uses roller bearings on the front pinion, and the 1 ton has ball bearings. I really couldn't see anything different in the service manual except that the cab chassis rear ends are narrorer than the regular pickup rear ends. The third members are interchangeable is what I've heard. When I fixed the rear brakes on my '70 I got everything I needed from AutoZone. A set of rear shoes to do both sides(HD shoes, 2 3/4" wide), new brake hose, and two wheel cylinder rebuilt kits ran me about 35 bucks.

Pretty sure the HO72 dually axles will have 3" shoes and supposedly they are harder to find. Don't know haven't needed to do mine yet. I would pick number one because of the better brakes and axle ratio.

I know the HO72 in my longorn is getting pretty expensive to do the brake job on...
almost 50 bucks on teh shoes...$13 core.
5.25 X2 for wheel seals...common part number still used well into the 90's on P-30 chassis.
$53 each on brake cylinders...and this is after 3 attempts to get the right ones.
$50 for new adjusters
10 bucks for hardware kit
I've been told drums are not avalible
These prices are from NAPA with a discount. i don't know how much of a discound...but the list prices (the B.S. price) it more than double on everything I listed

I appreciate ya'lls help fellows.

I just did a complete rebuild on a 4.09 rear.Still looking for studs,they are the only thing I haven`t found(got 10 so far).The Wagner book showed the same shoes as Dana,wrong!I know the`71 K/20 is unique,bigger and skinnier,as I recall.In `91 I did a `70 C/30.It was a major ordeal finding parts.Started at Chevy,got a few things,then went to the place that located the drums for my`71 K/20.Now,it seems more parts are being produced,like the world got smarter.There was a time when it felt like parts were discontinuing right`n`left as these trucks were getting around 10-15 years old.It`s actually better now.

I had to get new drums for my 1 ton Longhorn a few years back, wasn't a problem locating, but wasn't cheap either.

I replaced my wheel cyclinders on my 71 w/H052 and bought them from autozone, right part first time. I was suprised. Of course I went on-line and got the P/N before I walked in to the store. My drums looked good so I left them alone as were the shoes.

I didn`t mention it,but I meant I replaced "all" wear parts on this rebuild,drums,too.

I found new rear drums for my 69 K/20 for $150.each. thats really not that bad..

Keep it in prospective though. We buy brake drums for our dump trucks, full size class 8 dump trucks, for 80 bucks each.

One thing to think about...I know at least one vendor on this site sells disc brake conversion kits specifically for the Eaton axle. You can also use modified 14 bolt brackets. Then you get a choice of what discs and calipers to use. Maybe a little more expensive initially, but replacement rotors and calipers should be easy to find for years to come.

69GMC,you just answered a question I never asked.I was wondering about that.

And here they are, http://members.aol.com/blackbirdstrucks/index.html

Budweis installed this kit on his 70 3/4 ton. He posted some pics a while ago on the 4x4 forum.

TX,
You will obviously want the 4.10 ratio if you plan on going over 55 mph. My 68 C30 Motorhome came with 5.14 stock, and I drove it home 400 miles that way. Probably why it has 28k original miles...

I have done some eaton swapping, and here is what I observed:
The H072 and H052 center sections interchange freely. Some center sections have a pinion load bolt (supposedly to prevent pinion deflection). I haven't figured out the exact particulars, but all the C30 dually rears I have seen have the load bolt. I have had H052 centers with the load bolt? The one currently in my motorhome is a 72 4.10 with the factory locker and a load bolt.
I haven't had to deal with brakes, but...

I have a 1987 GMC C30 parts truck that was a cab/chassis (not a truck with a dually bed). The rear leaf spring spacing is exactly the same as the 72 C30 in my avatar. The total width of both rear ends is very similar if not identical. It looks like the driveshaft will bolt up with no modification. My 72 came without shocks, so that is not an issue, but the only difference I see is the shock mounts which you could easily fix. The 87 also has a load controlled rear brake porportioning gizmo, which I may or may not adapt?
So what I am trying to say here is... my 72 is going to get a 1987 14 bolt FF dually rear. More selection of gear ratios, easy to find (and cheaper) parts... you get the picture. For the 1967-1970 C30 guys, it is also a fairly easy way to upgrade to the bigger wheel studs and "standard" dually wheels.

Have any of the "6 wheelers" on this board used a 73-87 dually rear?

Chris

Hi there Chris h i am about to do the same on my 67 c30 chassis,i had a 87 dually with a dana 70 and 4.10 gears,but i am changing the front engine cradle also,its a simple bolt in to loose the manual steering and drums up front,+ where can you buy 18.5 x 5.00 tires?

I have the chance to get an 80's era dually rearend for a great deal.

Won't the later dually (not cab and chassis) rearend be much wider than the one in my truck now?

I dont know about 18.5 x 5 tires?
My 72 came with 18" split rims, but I have never heard/seen 18.5 ?
I will be glad to sell the 4 18" rims I have this spring. 2 mud/snow traction tires and 2 highway tread, but the tires are probably original to the truck!

Yes it is wider but the one i am taking out is no wider than the cab itself,I like the wider one to handle the loads better. And 5.13 gears wont help the gas milage, plus this has 2 trannys in it,a clark 4 spd with a spicer aux,trans ,yea old twin stick. great for pulling the mountain roads around here. The spring pads are the exact width and the newer trucks had a rear swaybar also.

TX,
The dually truck with factory bed rear end is way wider, the inner dual tracks the front tires instead of the outer dual.
Great for towing stability, and if you are making a flatbed, it shouldn't make much difference to you? You could make your flatbed another foot wider.
Of course, if you have to park in narrow spots, it might be more of a hassle...

I bought a bunch of 16 inch 2000 model rims toput on this and my other truck here that was a 80 3/4 burb when i started

Re: HO 52/ HO 72 question
 

I purchased a 1968 c30 GMC openroad, I believe it's the HO72, any help on rear axle seal part number, brake pad, basically rebuild kit.

Re: HO 52/ HO 72 question
 

From what I understand, and I could be 180 out, but seals and bearings are scarce but are a few still out there to be sourced, ring and pinion are no longer available.

If you need a total rebuild start looking for a 73-87 cab n chassis DRW 14 bolt parts truck. A cab n chassis will measure 63" WMS to WMS and 40" center to center on the spring perch's. The Dually Pickup rear ends will not fit, they are about 8"+/- to wide

Cab n Chassis will bolt right in with a couple of easy modifications on the shock mounts and flexible brake line.

Read This: https://67-72chevytrucks.com/vboard/...+brake+14+bolt

Re: HO 52/ HO 72 question
 

Re: HO 52/ HO 72 question
 

I second Torque King. I'd give them a call and tell them what your problems or needs are, and they will tell you what you need to buy.

I'd also look it up on Rockauto and look in the drivetrain section to see what they have available.