The Stovebolt Site Forums The Shop Area Driveline Eaton HO52

Well, I went and got the rear end out of the 71 C20 today. I went and looked at the glove box tag and it did not say anything about the rear end code. It did tell that the engine was a 350 and the transmission was a turbo-hydromatic. So, I went home and came back with the tools needed to remove the cover. I drained the oil into a pan, then removed the cover. I looked for the numbers and indeed it had the 10-41 stamped inside the gear teeth. The salvage crew removed the axle for me and loaded it on my trailer. I stopped at NAPA and ordered gaskets and a pinion seal. What brand of brakes are on the 71 HO52? I know they are different than my Huck brakes that are newly rebuilt.

The brakes on a '71 are likely Bendix. I know I had a 72 K10 and it had bendix brakes that were almost identical to my '51 3100.

The 4.10 center section should be able to bolt into your original housing if you want to keep the new Huck brakes in place. There's really no need to replace the entire axle assembly just to get the higher gear ratio. That 4.56 gear is very popular with the rock crawler crowd that runs ridiculously oversized tires, so there might be a market for it with them. They like the low ratios.
Jerry

OP -- Have you checked out our Tech Tip on this subject?

center section switch/upgrade on Advance Design 3/4 and 1-tons

The brakes on the '71 are Bendix and would be an easy swap to put them on your '47 *if* you wanted to do that. You would need to take everything off the axle from the backing plate out -- even the backing plate itself. It will bolt right up to your current axle (assuming we're talking an Advance Design '47 and not an Art Deco '47 ....)

But if your existing Huck brakes are new, there is no need to change out just yet. Run the Hucks until they need replacing and then upgrade to the Bendix. You'll probably want to do that anyway when you get to the relining-the-Huck-shoes part... Just remember that Hucks have to be adjusted periodically ...

Yes Thanks, I checked out the tech tips before I bought it. I disassembled the axle today. It looks like, in order to work on a HO52 Bendix brake you would have to pull the bearing hub to get at the drum. If that is true, (the wheels are still on this axle), that is not a great improvement. I know the Bendix are better brakes but, What Were They Thinking? I can pull my drums in 5 minutes after I take the wheel off. My Huck brakes are new on my truck. As long as I keep them adjusted, I see no reason to change.

As long as you have a source for relined brake shoes for the Huck system, (almost nonexistent) and don't mind doing frequent adjustments, there's no reason to change. A Bendix setup with automatic adjusters has no need to remove the drums until the linings wear out- - - -and the linings wear evenly, not like the Huck system that's notorious for wearing out one lining while the other one looks brand new.
Jerry

My local NAPA can send them for re-lining. I will look at the Bendix brakes further when I have some time.

That's the spirit, Lumbersawyer! I'm still running Hucks on my 3804. Plenty of highway driving and I'm still alive. Like Jerry says, they require adjustments from time to time and the shoes wear unevenly. Once I get a little more wear on my shoes, I'm going to swap them front to back on each wheel so they all wear evenly.

If you drive conservatively and you don't mind taking a more active role in maintaining the truck ... the Hucks will be fine.

And ... this is the best part ... you can join Jerry and I (he's my hero) on the back bench being cranky with folks who want to ditch Hucks for being death dealing evil straight from the pit of Heck. I still run bias ply tires and 6 volts, too.

Harrumph!

I have made a few improvements to my truck, it had a 59 235 in it and was 12 volts already, but, I installed an alternator, electric wipers, a radio, and a Gear Vendors Overdrive. With the 4.57 rear end I get a 3.55 final ratio. With the 4.10 rear end I'll have 3.20 final ratio. I have plenty of power now, so I'm looking for a nice cruse ratio and for more milage. I wanted to keep it a truck. Much like it was when I bought it, no changes to the front end, (it's nice and tight), interior, or drive train. I still have the lever shocks. I rebuilt the springs front and back with pins, bushings, and shackles. After looking at a lot of AD trucks, most don't keep them like they came out. I don't get why they do the independent front ends, or slamming them down to the ground, or a big V8, that would ruin it for me. My truck rides very well for a 76-year-old truck.

I removed the original 4.57 gear carrier today. And then I prepped the 4.10 gear set and installed it. New gaskets on the axle flanges and the gear carrier. I did not remove the back cover, did not need to. I had taken it off before and it was not leaking. The machined surface of the rear housing was never perfectly flat. It had an area that was not cut by the machining process when it was built. Extra thick gasket helped, but I had to use two gaskets to seal it up. I had to wait for my son to get off work and he helped lift the 4.10 gears into the axle housing. I have to let the gasket sealer to set up, then torque all the bolts tomorrow. Put oil in it and give it a try. It should be a nice improvement to my truck.

Doing great! Keep after it!

Well, I went for a drive today after the 4.10 gear change and replacing my fuel gauge. It was 37 degrees out today. I even turned on the heater! I drove 51 miles and my speedo is two miles an hour slower than my phone says that I am actually going. It was off the other way before by three mph. So, I can live with that. Now 55mph is 2100 rpm, and 60mph is 2250 rpm. Remember, I have a Gear Venders Overdrive. It has a .78 percent overdrive ratio. That gives me a final ratio of 3.2 instead of the 3.55 I had with the 4.57 rear end gears. Overall, I'm happy to have been able to do the switch and find this 4.10 Eaton that is in very good condition. There is no rust or pitting on the gears and the back side of the ring gear still has the grinding marks from the manufacture of the gears. The front drive side has a nice polish to the surface of the gear. The rear end was fairly clean inside.

Fantastic to hear how your swap worked out.

Hope the weather holds a bit longer for you to drive it more before old man winter starts socking things in.