Hi Gang,
I replaced my real wheel bearings and oil seals a few months back. I noticed that when I re-installed everything I had some play in the rear axle shaft (7.25 inch, 66 Dart). After everything is bolted back in place, I get about a 1/8" to 1/4" of play when I gently tug on the axle shaft.

What follows is an update to my original post...

So now I've got everything pulled apart. My oil seals are OK. Odd as it may sound, it looks like if I use the existing bearings (NAPA) with a wider collar, then that would work.

Here is the question I need addressed. Please see linked photo showing the original NAPA wheel bearing setup.

http://home.attbi.com/~thomas.kimpel/images/dart1.jpg

Is the collar supposed to extend to the end of this small ridge in the axle where the diameter changes? If so, then the fix is to replace the old collar with a new (wider) one.

Thanks,

Tom

That's a ton of play. It should be around 0.010" end play. I'm not too familiar with 7 1/4" rears, but there must either be an adjustment for endplay somewhere (check factory serv manual), or you have an incorrect bearing/axle shaft/C-clip...

Hope it works out,

Lou

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Home of Slant6-powered fun machines since 1988

Lou's right. The right axle has the adjuster built into the retainer. Don't forget to install the adjuster lock.
If you have a posi then you have a 3 pc spacer button that installs into the spacer block in the differential. Make sure it hasn't separated and dropped into the sump. If the button isn't in there you can't set the endplay.

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'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

So I went to another parts store and had them pull some bearings off the shelf and they look exactly like the one's I got from NAPA which are Federal Mogul.

As per Lou's comment- "The right axle has the adjuster built into the retainer" I see no such item that could be construed as an adjuster lock. The Haynes repair manual I have discusses this in relation to the 8.75 axle but not the 7.25 one. FYI: The picture I posted shows the right axle.

So how might I know if I have posi?

Lastly, just to make sure I have everything correct, which way is the oil seal supposed to go- with the open part of the "C" towards diffrential or towards the wheel?

Sorry about all the questions. I've only been working on cars for 9 months now.

Tom

The axle bearing on a 7 1/4 is a sealed ball bearing, there is no axle end play adjuster. This is the same as the "Green bearing" used on the 8 3/4 to eliminate the end play adjuster on that assembly.

These conventional ball bearings do have a good amount of endplay to them but not 1/4 inch, I would say up to 1/16 is acceptable. (.062)
As for the bearing retainer collar, that does not have to extend all the way out to the shoulder, it just needs to be tight against the bearing.
The seal goes with the open part of the "C" facing inward.

The truth is that the 7 1/4 axle bearings tend to be problematic due to their small size and lack of end play adjustment. All you can do is be sure the collar is completely pressed down against the bearing and the axle is seated completely into the axle housing's "cup".
DD

Ok, the pic you have linked, doesn't show the other side of the retainer plate. So I can't tell if you have the correct retainer. The left axle ass'y has a plain retainer. The right axle shaft is the same as the left axle shaft, but the ass'y is different. The difference lies in the retainer. The right retainer has internal threads, and a spanner nut with external threads. The spanner threads into the right retainer. By varying the thread engagement you can control the clearance between the inside end of the right shaft, the spacer block, and the inside end of the left axle shaft.
Everything should be similar, maybe smaller, to the pictures of an 8 3/4" axle. Later axles (8 1/4, 9 1/4) may (I don't remember for sure) not have the adjusters. I know they use c-clips to retain the axles, and the axle brgs are in the axle housing tubes, not pressed on to the axle shaft like yours.
The 'open' or non-posi diff has big open windows through which you can easily see the spiders. The posi diffs have springs and plates in there to load the clutches.
If you have limited-slip(posi), hold the frt yoke and rotate by hand one wheel, the opposite wheel will turn in the same direction.

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'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

I didn't know the 7 1/4 didn't have end play adjustment! I was assuming the 7 1/4 is just a very scaled down 8 3/4, as far as hdwe goes. I never really tried fixing those things I just swapped them out for bigger axles. Boy, there's another reason to upgrade those things.

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'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

Much thanks to everyone for helping me solve my problem. I obtained new (correct) oil seals (Federal-Mogul Part # 484058) which were just a tad wider than the ones I initially had in there. It appears I was given the wrong parts the first time around. I also made new gaskets and took my time putting everything back together. I feel a lot safer now knowing everything is correct.

Thanks again,

Tom

Did the new axle bearings make the unit run quieter?
I find that most of the noise out of a well used 7 1/4 comes from the axle bearings.
DD

Good question. You are probably correct as you have "Guru" listed under your screen name. I put the bearings in about 3 months ago and wasn't paying attention to any reductions in noise. My car runs very smooth and quiet following a front end rebuild, new rear springs, and new axle bearings all the way around. Perhaps I should turn down the volume of my MTX amp and 2- 10" subs once in a while. I'm sure the Dart has lots to tell me.

I think I just might send you some good Oregon beer for all that you have done for me and the other /6ers through this bulliten board. Send me an email with an address to ship it to and I'll get it out in the next week or so.

Tom

I like the sound of that offer!
Happy Holidays
DD