Rear end questions
 

I'm new to these dually rear ends and need some info. Can someone please tell me what the smaller 3/4 bolts around the hub do other than just hold the center cap on. I also think all the lug nuts are backwards.
I have been told they are BUD wheels also if that makes any difference.

#1-? The 3/4" bolts where all loose today and several where close to falling out do they typically do this and do I need to lock tight them down?

#2-? If I take them off what is inside? Is it something that needs to be looked at on occasion? It looks like it's full of grease to me.

#3- ? Does any one know if I can buy some simulators to fit them?
What do I need to know other than they are 16" wheels.
Any and all help would greatly appreciated.:chevy:

Re: Rear end questions
 

going to say full of bearings

Re: Rear end questions
 

The 8 inner bolts attach the axel shaft to the bearing hub. You can use loktite on these bolts. If you remove these bolts, you can slide the axle shaft out, and then get access to the rear wheel bearing.

The lug nuts do look backwards. To know for sure, remove one and see if the wheel has a tapered hole for the lug nut to fit into. If there is a tapered hole, turn all the lug nuts around, this is what keeps the wheel properly centered.

Re: Rear end questions
 

That's a full floating axle. Take out the bolts on the hub and you can slide the axle out without even having to remove the wheels. Yours appears to have been leaking like a sieve from the flange seal area.

Gary

Re: Rear end questions
 

Thank you and yes you can see the taper on the wheels in person. I will swap them around.
So I can take this off and look to check the grease and put it back together without any harm. There where several of them almost ready to fall out and I was worried they had messed something up in the hub but it sounds like it's just a cover. Good. :chevy:

Re: Rear end questions
 

It's not a cover. It is the end of the axle flange as it bolts to the hub. You remove the 8 bolts... and that lets the axle slide out.

Gary

Re: Rear end questions
 

That hub looks something like this :

Re: Rear end questions
 

Looks something like this after your axle is removed :

Re: Rear end questions
 

Yeah Andy, what you are looking at is the end of the axle shaft. The flange bolts are what fastens the hub to the axle. With no bolts the differential will spin the axle shaft and the wheel won't turn. That flange gets sealed to the hub because your rear gear oil is free to flow from end to end. Locktite is a good idea, but I don't use it. There is a torque spec on those and that will hold it fine. You'll want to add gear oil. Probably a good time to drain and add fresh.

There used to be simulators that just pop on like hubcaps. I believe they weren't DOT approved and maybe not sold any more. They were fine, but not cool for commercial vehicle under DOT scrutiny. The others are held on by lug nuts. The thing is, before '71 the C/30s gad 7/16" studs and flat backed castle looking nuts. There is no bevel in the wheel. That's why the lug nuts are reversed. On the disc brake trucks they have 9/16" and use a spreader plate (ring with 8 holes) over the studs and wheel that have bevels. Simulators go on before those, then the center caps cover that, then the lug nuts go on. They supply stainless acorn nut caps to pop on the lug nuts. Check www.outawdirect.com

Re: Rear end questions
 

Here is one of dozens of videos about how they are constructed. If they are loose you may have some stripped threads. I had that problem on my 52. I had to convert to studs and drill and tap the holes deeper then loctited them permanently. Torque them back to spec carefully.

https://www.google.com/url?sa=t&sour...wYnHpwRJt-T9Rw

Re: Rear end questions
 

As I'm researching this some,
Is it not correct that these have 1/2-20 studs;
Not 7/16.

My reading suggests 1/2-20 up to 1970;
Then 9/16-18 studs from 1971 forward?

Re: Rear end questions
 

Ok so from what I just read. I need to take the covers off clean them up good and drain the rear end and fill it back up...correct. Is there a gasket that should go on the hub plate? I see signs of either a gasket are sealer coming out from around the bolts.

I guess I need to find a book are on line directions for this rear end.
Any help on that.:chevy:

Re: Rear end questions
 

I believe there may be a gasket, but mine didn't have any when I tore it apart so I used Form-a-gasket. Here is a link to Dana's tech library.

http://media.spicerparts.com/media

Re: Rear end questions
 

As far as wheel stud size, it's been a long time since I had my '70 C/30. I said 7/16" because as I recall (or had it in my mind for so long) I was amazed the studs were smaller than 1/2t. I guess I got that twisted up in my memory, if I'm wrong. Maybe I was just amazed they weren't 9/16" after owning a bunch of 3/4Ts with that size. either way, you knw what you have.

Here is a picture of what you have, except with disc brakes. It shows what you have going on with the axle and hub. There is a thin steel gasket. I use RTV

http://www.billavista.com/Tech/Artic...s/IMG_3430.jpg

Inside there is your outer bearing on a hollow spindle,

Re: Rear end questions
 

dual wheels are dead flat on both sides....that allows you to use the rim as an inner or outer which you couldnt do if it was coined around the lug hole like a regular rim...dont know about 3/4s but on my 1 ton motorhome there are circular retaining plates that go on last (covering the area thats rusty on your rim)that are about 2 inches wide and about 1/4 inch thick that have the raised and tapered holes for the lugs

Re: Rear end questions
 

if you break an axle or a c clip on a 1/2 ton rear you lose a rear wheel as the axle and wheel slide out the bearing and leave the vehicle....a floater rear has a set of inner and outer wheel bearings and a grease seal just like a larger version of what you have on a front wheel...normally retained with 2 large nuts ....you adjust preload with the inner nut,theres usually a lock plate in the middle and you tighten the outer against the inner to keep it secure, then bend some tabs on the lock plate to further keep the assembly from coming loose (instead of a cotter pin like on a front)...and they are packed in grease also because the gear oil that can run down the axle tube really isnt sufficient to lube them...this way if an axle breaks the wheel remains firmly attached to the vehicle....its a safety design for larger vehicles that carry more weight and see more abuse...the drive axle is splined on the end and slides in like a normal one but no c clip and no need to pull the rear end cover...that plate you see is molded on to the end of the axle like the flange with the wheel studs would be on a 1/2 ton ...it attaches to the hub with your loose bolts....there should either be a gasket or sealer to keep the goo in place

Re: Rear end questions
 

Ok thanks guy's I starting to see that I need some maintenance work done on this rear end for sure. Thanks for all the info. Keep the info coming. I guess this weekend I need to prepare to at least pull the covers off and see how well the grease packing is in there.:chevy:

Re: Rear end questions
 

They aren't covers though. They are the forged end of the axleshaft. When you take the bolts out and pull, the ENTIRE axle shaft comes out.

The axle shaft in a full floater's only job is to propel the vehicle forward the hub, hollow spindle, and opposed bearings support the load.

Sometimes they don't want to come out and there are a couple of extra holes you can thread a bolt into and they push against the hub rim and that will pull the axle out

Re: Rear end questions
 

You'll also need a special hub spindle nut tool that has raised nubs that lock in to the recessed spots on the spindle nut.


It'll look like this:

http://i.ebayimg.com/00/s/MTIwMFgxNj..._id=880000500F

Gary

Re: Rear end questions
 

The 4x4 guys know all about these. Check out this thread as it may help you. Search the 4x4 and off road section. And for more information than you probably want you could check out the Pirate 4x4 forum. Have you confirmed which rear end you have?
http://67-72chevytrucks.com/vboard/s...d.php?t=536119

Re: Rear end questions
 

I have owned a lot of different 4x4 trucks over the years. So I have about 6 different spindle nut tools. :lol:

Gary

Re: Rear end questions
 

my 69 gmc 1 ton has 1/2 " lug bolts

Re: Rear end questions
 

use any red or blue silicone gasket sealer, you dont need a gasket

Re: Rear end questions
 

you dont grease the rear bearings on a full floater like you have, the gear oil in the rear end travels to the ends and keeps things lubed...when you initially install new bearings, you can put some white grease on them so they dont run dry until the oil gets to them and the white grease will mix with the gear oil....

Re: Rear end questions
 

I used Permatex 81182 with a gasket, like Tim mentioned. It's made specifically to work with gear oil, and I'll never use regular RTV or silicone again if gear oil is involved. Good stuff.

https://www.permatex.com/wp-content/...6/02/81182.jpg