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Questions on 8 3/4 axle in 64 Polara

Posted By: MOPAR_AMC_FAN

Questions on 8 3/4 axle in 64 Polara - 12/27/10 11:56 PM

From what I've read, the 8 3/4 axleshafts in 64 aren't as strong as the later axleshafts (66-up, I believe). From what I understand, it's almost like the two-piece shafts found on AMCs where the hub is pressed on. I'm not positive about this, but either way, I want to get rid of them. My questions are... Can you just replace the axleshafts with later model units or do you need to swap the whole axle? If you swap in a whole other 8 3/4 from a later model B-body (pre-71), is it a bolt in swap? Any other things I'm missing?

Thanks!
Posted By: 64dodge572

Re: Questions on 8 3/4 axle in 64 Polara - 12/27/10 11:58 PM

You must replace the housing/axles. 1966-67 B-body is the assembly you want, and it will be a bolt-in change, track will be slightly (1") narrower.

Wayne
Posted By: John_Kunkel

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 12:45 AM

Board member Doctor Diff can supply you with flanged axles to fit your current housing, you'll have to scrounge the brake backing plates and drums from a '65 or later.

http://www.doctordiff.com/
Posted By: scratchnfotraction

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 12:53 AM

you can get a new set of axle with the modern flange and large brake offset to go in the 8 3/4 housing you have

I used a early A-body keyed axle 8 3/4 housing with a set of moser axles and run large c-body brakes and backing plates 11x2.5 drums 5on4.5 wbp

DrDiff has the axles also

some of the older 8 3/4 chunks are diff on the splines or something but think its the early 57 to early 60 8 3/4 though

shoot dr diff a PM and he can set you straight on the chunk and axle thing

dont swap housing unless its a gotta be thing and save some coin

my axles were about 299$ a set with non adjustable green bearings

now that A-body axle is bolted in the truck to tuck 12" rims in the fenders

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Posted By: sam64

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 01:18 AM

get one out of a 65 b body,flanged axles and correct width.i've seen'm as low as 150.00 complete.
Posted By: MOPAR_AMC_FAN

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 02:16 AM

Thanks for the info, guys. I already have a 3.23 sure grip chuck to go in whatever axle, so I just needed to figure out the complete housing vs. just axles issue.
Posted By: badblack68

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 02:27 AM

The non flanged 8 3/4 rears back then were strong enough to hold up in the 13:1 compression manual transmission max wedge cars...
Posted By: towguy76

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 03:27 AM

how big a pain is it to work on those with the 2 piece axles? I just bought a 56 Dodge 1/2 ton truck and it has the 8 3/4 with the 2 piece axles. According to a previous post, my chuck more than likely has a different spline count so i wont be able to swap axles with out buying a new diff for it. my license plate will probabaly read: MNY PIT (money pit)
Posted By: scratchnfotraction

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 04:16 AM

wait till you try to remove the hubs

you can losen the nut and drive a few figure 8s and they will break loose some times

most I have seen have to be smoke wrenched off

you need to talk to DrDiff for sure

there is a good write up on the history of the 8 3/4 and talks about the diff in axles and chunks on the 57 up early ones in the archives IIRC

some thing about splines and the thrust block size or what not
Posted By: towguy76

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 07:38 AM

Please tell me that the drums come off the hubs since I need to do maintenance on the brakes.
Posted By: SportF

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 01:24 PM

The top shoulder of the stud is swedged over and holds the hub to the brake drum. They did this on the front hub as well. This is such a good swedge that if you press the stud out of the hub it can open up the hole as the swedge goes through the hub. In any case, to get the drum-hub assembly off you need a heavy duty puller made especailly for this task. And I have had them where they won't come off, with any method, including cutting the end of the housing and axel off and pounding straight down on the axel stub while heating the hub!

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Posted By: therocks

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 05:48 PM

To get the drums off you need the proper puller.I have one that I bought for the 57 and 62.It attaches to the studs and tightens on the big stud that the nut is on.Then there is a handle that you smack with a good sized hammer and they pop off the key way.The 61 we had some moron pressed the drums off the stub.They were so bad that the pedal went up and down when you hit the brakes.Local yard had a set that I bought for it and fixed that problem.I bought my puller from Ebay.Cost me like 35 bucks and was an old I believe Mac.Ive done tons of the rears and never had one that wouldnt come off.My kids 62s were the worst.Took me about and hour to get them off.Rocky
Posted By: MOPAR_AMC_FAN

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 06:04 PM

I replaced my 2-piece axles with one piece Moser axles in my AMC, but had to have the hubs removed before I sent my stock axles to Moser. I found a shop that would remove the hubs with a BIG press. Sounded like a gunshot when the hubs came off. Yikes!

So, to use the later-than-64 sure grip chuck I have, the easiest way would be to swap to a later axle, preferably a 65?
Posted By: SportF

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 07:00 PM

Well, that 64 sure grip will work, the splines are all the same, but the sure grip tapered axels are different length than standard axels, and that is a little known fact. But if you make up some axel shims (which is how the axel bearings are pre-loaded) you can make the standard axels work. It will take about .125 to .150 shims each side, if I remmber correctly. If you can get green bearings for those early axels that would take care of that problem, but I don't know if you can. The grease seal for those tapered axels is in-on the backing plate and the bearings are lubed with the 90W in the housing. The 65 and newer have an oil seal a couple of inches down inside the housing and the bearings are lubed greased-or sealed from the outside.

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Posted By: QuickBpBp

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 07:05 PM

I threw a 68 8 3/4 rear outta a GTX and never had a problem....Bolted right in....
Posted By: MOPAR_AMC_FAN

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 07:56 PM

The 3.23 sure grip isn't a 64 unit. It's a 4.89 case.
Posted By: John_Kunkel

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 08:05 PM

Quote:

Well, that 64 sure grip will work, the splines are all the same, but the sure grip tapered axels are different length than standard axels, and that is a little known fact.



'64 is the first year that didn't used different length axles for SG and non-SG.

The '64 B body rear end dimensions are a holdover from the Forward Look days, wider than any other '62-'70 B body rear.
Posted By: towguy76

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 09:11 PM

Here is my rear drum and 2 piece axle setup. So i gather that in order to inspect and repair the brakes i am going to have to pull the hub off the axleshaft. Since the studs need to be replaced anyway, can i cut out the old ones, remove the drum from the hub, install new modern studs and have the drum removable from the hub for ease of use?

on another note, my front drums use bolts that thread into the hub like a Mercedes instead of studs. They are reverse threads on the driver's side like other pre 70s Mopars though.

Posted By: SportF

Re: Questions on 8 3/4 axle in 64 Polara - 12/28/10 10:27 PM

Certainly didn't know that '64 is the first year of non-different length sure grip axels.

Can you cut off the studs to get the drum off? Yes.......but its not easy. You still will have the swegded shoulder of the stud if you cut it off flush from the outside. You could go in there with a big drill bit to drill some of the swedge, but that is really a drill press operation and you can't do that on the car. I have removed a number of these studs by cutting the head off and pushing it out from the back, but the drum has to be off for that. And, this is a very good grade of stud, so that isn't easy in any case. You really need to get one of the pullers and do it that way, in the end its the right way, and its the easiest way. Good luck to ya!
Posted By: 6T4 Polara

Re: Questions on 8 3/4 axle in 64 Polara - 12/29/10 12:49 AM

Drum off use a swegde cutter often found in older auto machine shops.This will save the drum and get new studs pressed in.

John
Posted By: Anonymous

Re: Questions on 8 3/4 axle in 64 Polara - 12/29/10 01:25 AM

Quote:

Here is my rear drum and 2 piece axle setup. So i gather that in order to inspect and repair the brakes i am going to have to pull the hub off the axleshaft. Since the studs need to be replaced anyway, can i cut out the old ones, remove the drum from the hub, install new modern studs and have the drum removable from the hub for ease of use?

on another note, my front drums use bolts that thread into the hub like a Mercedes instead of studs. They are reverse threads on the driver's side like other pre 70s Mopars though.





Throw the whole thing away and put in a later B-body rear.

You'll be happy you did!

My '63 330 got a '70 Charger rear.

I get knots in my stomach just looking at that rusted together mess...
Posted By: NicksGarage

Re: Questions on 8 3/4 axle in 64 Polara - 12/29/10 06:20 AM

This is the correct puller for those drums. Yes they can be a real pain I've never had a Dodge one I couldn't get off but on my '54 Willys I ended up getting the drums off the hub which was a major ordeal.

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Posted By: therocks

Re: Questions on 8 3/4 axle in 64 Polara - 12/29/10 01:42 PM

Nick thats the puller I have.Got it off Ebay.My kid first put a 69 C body under his 62 300.It fit but we had to pull the springs out a bit to seat them.Then he changed it and installed my 65 B body.It fits perfect.He runs 10 1/2 inch wide tires under it with no problems.Rocky
Posted By: towguy76

Re: Questions on 8 3/4 axle in 64 Polara - 12/29/10 05:35 PM

Pulling that rear and swapping in something else was definately an option i was considering since i am not a fan of the 2 piece axle setup and the condition if this one. Just have to check measurements and see what will fit and what i can afford.
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