Removing Rear Axle Flange - '73, RM350

Wendell · July 19, 2012, 02:11 PM

OK team. Need a little advice here. I'm attempting a rear brake job on a 1973 Dodge RM350. I have a leaky wheel cylinder on the left rear. I have the wheels off and have the flange nuts off. However, I've tried whacking the center of the flange cover as the service manual says and it is stuck like Chuck. Any ideas out there? Anyone out there had this problem? Any advice would be welcome.

75Travco · July 19, 2012, 07:49 PM

Each stud on the hub has a tapered split ring that has been tightly wedged in place by the nuts. Releasing the conical rings requires a fairly large impact force. A medium whack with a minimum three-pound hammer should do the trick. A sledge hammer is even better, don't have to hit as hard. A "light" hit will not release the axle, and a small hammer will not do it. Suggest leaving at least one nut partially threaded on, sometimes the axle will break loose and come flying out and the nut will snub it.
The are some physics involved with this!

ClydesdaleKevin · July 19, 2012, 08:04 PM

Agreed. You have to whack it pretty hard, dead center...try not to hit anywhere near the edges so you don't distort or damage anything. A previous owner might have used a sealant which is making it stubborn, so if you try to pry under it, do it gently so you don't have any gear oil leaks later down the road. One of mine on my old 72 was stubborn, so gentle taps all the way around with a wood chisel...making sure you don't gouge the metal at all...and it came free.

Kev

DaveVA78Chieftain · July 19, 2012, 08:41 PM

Here is the top level brake info for you chassis from my website.
http://dave78chieftain.zxq.net/M400_73-75-RM350.html

Select the Rear: Bendix Twinplex 12" x 3" link http://dave78chieftain.zxq.net/TwinplexBrakes.html

lots of pretty pictures including the offending cone washers that are keeping the axle in place.

Dave

Wendell · July 20, 2012, 09:40 AM

Thanks guys. Now I have a little better idea of what I'm dealing with. Those cone washers seem to be the culprits all right. I was using a 3 lb. hammer, but I guess I need to whack it harder or try the chisel approach.

Wendell · September 15, 2012, 02:51 PM

I'm making progress, but it's been slow. Until recently, it's been too darn hot here to want to work in my shop, but the beginnings of fall have brought new life.

I got the axle shaft out today!!! It took several applications of a torch, a lot of Liquid Wrench, a chisel, a nail set, but mostly a lot of patience and I finally got the last two cone washers out and then the axle shaft came out without much trouble after that. Man, that thing is nasty.

Now then, can someone tell me what size the hut nut is? The manual says to use "Special Tool DD 1245" to remove the outer hub nut. I think that's a 2 3/8" job, but if someone can enlighten me, I'd really appreciate it and a hint on where to get one would be nice too.

My brake parts are scheduled to arrive this week, so I'm getting anxious.

Thanks for the great pictures Dave. They are invaluable.

ClydesdaleKevin · September 16, 2012, 06:41 AM

If I recall correctly, I couldn't find a socket big enough when I did the rear brakes on the 72...but since it was always bathed in gear oil, once I removed the retainer it was easy to loosen with a pair of channel locks. Same thing with reinstalling it...the channel locks did the trick.

Kev

jkilbert · September 16, 2012, 06:56 AM

I picked up a big enough socket at NAPA.

Wendell · December 29, 2012, 05:27 PM

Still working on this brake job. Got the axle shaft removed, got the large nuts and lock washers, etc. out of the hub, but I can't seem to get the brake drum off. I've loosened the adjuster star wheel as much as I can get it to turn, but in truth it would only turn about a half a turn. The drums will not turn/rotate. They seem to be stuck to the shoes. Have I failed to remove something here that might be holding them on? Suggestions?

ClydesdaleKevin · December 29, 2012, 08:54 PM

Been there done that, and its like a Chinese puzzle!

There is a groove worn in the drum from braking, and that groove holds the drum in place. You have to coax, hammer, pull, talk dirty too, and otherwise manipulate the drum off the axle.

It can always be done...just with less finesse than we are used to working on less than heavy duty systems.

Kev

DaveVA78Chieftain · December 30, 2012, 10:53 AM

One half turn would be no where near enough. It will need to turn several full turns.
Your setup should be like the the one in figure 2 (Bendix) in this description.
http://vintage.mitchell1.com/PClubData/chassis/chts76/V2D7610036.pdf

Refer to Figure 6 on this page about how to release the star adjuster.
http://dave78chieftain.zxq.net/BXDuoServoBrakes.html

Please note that many of the photos on that page are of the Chrysler design not the Bendix design. The shoe hold down springs are much different between each type. Next time I dig into mine I will need to take pics of the Bendix type.