swing axle bearing cap question

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bones
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swing axle bearing cap question

Post by bones » Tue Aug 07, 2012 11:08 pm

Which direction does the outer spacer go on the axle - outer beveled edge points to the wheel or the backing plate? Hard to tell from the picture and it was all apart from the get go. Thanks

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Marc
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Re: swing axle bearing cap question

Post by Marc » Tue Aug 07, 2012 11:48 pm

Swingaxle, yes?
Thinner edge inboard (towards the bearing). The I.D. should also have a bevel on the inboard side which provides room for the small O-ring.
This puts the "sharp" O.D. outboard, so if the spacer's on the axle before you install the cover it may snag the seal and damage the lips and/or dislodge the spring. Better to install the spacer after the cover's on, or (my preferred method) put the spacer in the cover/seal and install as an assembly.
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Re: swing axle bearing cap question

Post by bones » Wed Aug 08, 2012 6:36 am

Thanks Marc. This is what I figured. What doesn't seem right is the inner beveled area ID is smaller than the OD of the small O ring when the O ring is slipped over the axle. When all is tightened down the small O ring looks like it will be crushed and damaged. This car has narrow 67 brake drums - is the oil slinger required?

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Re: swing axle bearing cap question

Post by bones » Wed Aug 08, 2012 7:57 am

I also noticed the bearing cap does not have a weep hole. Does this make any difference?

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Marc
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Re: swing axle bearing cap question

Post by Marc » Wed Aug 08, 2012 11:50 am

You can omit the slinger, but if you do any lube escaping past the seal will end up on the brakes unless the bearing cover (and backing plate) have weep holes. `67 bearing covers and axle tubes are unique (the depth of the bearing recesses is different from that of older or newer components) so you've got to be careful that the tube and cover match. If the cover's too deep for the axle tube the bearing will have endplay; too shallow and the backing plate won't be held securely.

(I know that's been mentioned before, I'm just reiterating it for the benefit of anyone searching the subject in the future)

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Re: swing axle bearing cap question

Post by bones » Wed Aug 08, 2012 12:40 pm

Although the car is a 67 the axles tubes / axles are from an earlier year since they are shorter than the 67. Not sure what year the covers are because they came on the car. Are the 67 deeper or shallower than the earlier models?

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Marc
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Re: swing axle bearing cap question

Post by Marc » Wed Aug 08, 2012 6:15 pm

`67, `68 (including post`68 swingaxle in other countries) and all swingaxle Type III have the "long" tubes - approximately ¾" longer than pre`67 with the added length all in the end casting between the springplate bolt flange and the outboard end.

`67 tubes have a ~1/8" shallower bearing recess (so their covers are deeper than `68/Type III). Since the `67 axle shafts are the same length as the the other "long" axles from inboard end to inner spacer, this means the `67 axles run a hair further out 'twixt the fulcrum plates than do the other long axles, giving `67 a wider track width by a whisker (assuming identical dimensions on drums and rims).
`67 'Ghias used long-spline axles (as did Euro-spec Beetles with front disc brakes) and I honestly do not know if they used tubes and covers with the US-market `67 Beetle dimensions or if they used the `68-up Type I/all swingaxle Type III dimensions. I owned an Italian 1500 `67 Beetle but too many transmission/axle combinations have been in it for me to recall which ones it started out with - I no longer care anyway, since we dropped the body on an IRS pan ;)

Another "gotcha" when working with swingaxle parts of unknown vintage is that the thickness of the inner bearing spacer was changed in early `62. The old one was 5.9-6.1mm thick, the newer part is 6.45-6.65mm thick.

The recess in the cover should measure (within a few thousandths) the same as the distance from the backing plate to the outboard side of the wheel bearing outer race, with the bearing/axle pushed inwards as far as it will go.

Are your drums drilled for the slinger tube?
Last edited by Marc on Sun Mar 31, 2013 2:42 pm, edited 2 times in total.

bones
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Re: swing axle bearing cap question

Post by bones » Wed Aug 08, 2012 7:45 pm

The spacer is .595, the cap recess is .373 and the bearing from the backing plate to the bearing is .383 without the large O ring. The distance from the center of the cap to the drum center surface is .311 and from the back of the bearing cap to the seal is .695. On the drum I don't see a "tube". The center of the drum has a small chamfer around it's outer margin

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Marc
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Re: swing axle bearing cap question

Post by Marc » Wed Aug 08, 2012 8:16 pm

If the drums have no provision for the slinger tube, you should either drill one or convert to the later "weep-hole" arrangement - to run with neither is asking for trouble.
The ~6-6½mm spacer I referred to above is the thinner INNER one, that goes on the axle shaft before the bearing. It sounds as though you have the correct cover for your axle tube (the bearing projection being just barely more than the cover recess - if you were to add a paper gasket before the O-ring it'd be nearly identical) but I can't provide you with measurements for comparison since I turned my back on swingaxle many years ago in favor of the far better/safer IRS setup. We'll need to wait for someone to chime in with some numbers...

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Re: swing axle bearing cap question

Post by bones » Wed Aug 08, 2012 9:01 pm

Thanks Marc- the gasket is .010 or so so yes the cover seems OK. What do you think about drilling a weep hole in the cap and backing plate? What size is the hole and where is it located. I agree IRS is much better and that's what I have on my Ghia. This is my son's car and unfortunately he's lost interest and wants a different car after 10 years. I can't really blame him but I really don't like working on his car and he just got his hand out of a cast so he's useless. It has been a good father son project when he was living here but during and since college he's lived away. Needless to say he hasn't done regular maintenance. None the less the learning experience he's received got him his BS in ME and next May he'll have his masters in ME.

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Re: swing axle bearing cap question

Post by Pablo2 » Wed Aug 08, 2012 10:15 pm

Marc wrote: Another "gotcha" when working with swingaxle parts of unknown vintage is that the thickness of the inner bearing spacer was changed in early `62. The old one was 5.9-6.1mm thick, the newer part is 6.45-6.65mm thick.
I'm gonna have to make a note of that. I have a use for those earlier ones. Thanks, Marc .. I always learn something from your posts.
aka Pablo, gears, Geary
9.36 @ 146 in '86

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Marc
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Re: swing axle bearing cap question

Post by Marc » Thu Aug 09, 2012 12:51 am

That change came at VIN 4388450 (mid`62).
Pablo, can you help us out here? If the bearing protrudes .383" beyond the backingplate, is there a common bearing cover with weephole that'll fit properly? The depth of the bearing recess in the "unholy" caps now in use is .373" (~9½mm).

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Re: swing axle bearing cap question

Post by Pablo2 » Thu Aug 09, 2012 8:31 am

Sorry, but it's been many years since I've touched or seen any of these parts. I wish I could help. I've seen a couple threads lately in which it seems improper combinations or installations have caused issues in the bearing/backing plate area ..
It's so easy to grab an incorrect bearing retainer or such from a parts bucket. Your mention of the early & late spacer sizes points this out.
aka Pablo, gears, Geary
9.36 @ 146 in '86

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Re: swing axle bearing cap question

Post by bones » Thu Aug 09, 2012 8:39 am

Thanks Marc and Pablo. Does anyone have a picture of a cover with a weephole and the appropriate backing plate. I'm thinking and that's dangerous but perhaps what I have can be be drilled.

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Re: swing axle bearing cap question

Post by fusername » Thu Aug 09, 2012 1:09 pm

http://www.dunebuggyarchives.com/ShortVSLong

axle tube ID, easiest info I seen anywhere
give a man a watch and he'll allways know what time it is. give him two and he can never be sure again.

Things are rarely just crazy enough to work, but they're frequently just crazy enough to fail hilariously.

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