Something is very wrong

[Ignatzcatz]

Here we go, re-assembly of 356 rear hub.
All parts nice and clean, start with the small spacer with the chamfer to the inside, position the bearing into the axle, next is the 52mm by .5mm washer then the smaller O ring followed by the larger spacer (aprox 44.5 x 16mm) with the chamfer relief to the O ring. The 62.44.12 seal sits in the bearing housing with the larger O ring around the outer circumference of the bearing, I put one 0.1mm shim into the bearing housing, then carefully fit it all together with the back plate and my one is a VW piece, now the really difficult bit - fill the trans with 3 litres of EP80 and then watch my rear hub do an acceptable version of the Torrey Canyon. The oil pi@$es out.
I've had three goes at this and I'm not a happy bunny. It's the last job before the car goes for it's MOT and I'm stumped, what am I doing wrong? I would post a pic of the large puddle of oil on the garage floor but a) I think you can imagine this and b) I have severe problems posting pics on this website. However constructive advise would be gratefully received

[BD55]

Article here from Registry, for a disc brake car but may be similar...

https://porsche356registry.org/article/145

Is it just a case of, you have the axle tube hanging down and the oil has found its way through, that's not just a leak! Was it leaking bad before?
Simon

[roy mawbey]

This is not the easiest of jobs. I have the factory manual, Elfrinks manual and various parts suppliers books.

1). The parts supplier Stoddard and Roger Bray specify the same oil seal code number for 356,356A and 356B being 644.34.192. The 356C is different. Your number is not the same at all. Are you sure the oil seal is correct?

2). Did you set up the axial play of 0.05mm - 0.15mm between the brake backing plate and the rear wheel bearing to get the best compression value? ( using the shims )

3).Are you working to a factory or Elfrink manual to re-assemble. These books show the layout of the parts and the correct way of fitting. I have taken a photo of the Elfrink pages which I could e-mail you.

Did you put on the drum and axle nut after assembly and are you sure the seal you used was not tipped or out of line when you installed it if in fact its the correct one?

Its too complicated for me to define the step by step replacement of parts in the correct order I guess you did follow a book, the inner spacing ring does have the radius towards the inside and matching the half shaft radius.

For the oil to really come out that fast it must be a big clearance somewhere, hope you can find it soon.

Roy

Roy

[Kneeslider]

As a coincidence, I have my C gearbox out for the replacement of the bearings, and discovered after putting my car back on the road that the gearbox oil was able to leak past the seals and contaminate the handbrake shoes and end up on the wheels.

I am not sure, but I think that the oil slinger washers were not fitted to the car when it part built in the USA. I have a set of new seals from PRS, but Elfrink seems a little vague about how this goes together.

The registry threads don't seem to be too illuminating either. Probably the best course of action is to wait till I get my gearbox back, and it will all become a little clearer when it is all in front of me.

[roy mawbey]

The factory manual is really not any clearer than Elfrink. Both of those books follow each other sometimes almost to the word. I do know the seal has to be carefully installed so its not tilted in any way. And your 'C' model has the different seal to the earlier models. I don't know how they differ though?

Roy

[Ignatzcatz]

Thanks for all the responses, as there were no "you dumb schmuk, you've put the widget where the spronket should go" I have to presume my order of assembly was basically correct.
The number I gave for the seal which in fact should have been 44.62.10 and not 12 is not a part number but simply the internal, external and width dimensions of the seal, the only other digits on it are 'SOG 105683'. It fits tight in the bearing housing and snug around the spacer so I reckon it's right.
I don't know what 'axial play' is, and I didn't do any specific measurements.
My assembly procedure was taken from a 356 Registry print out. I do have a basic workshop manual but it is not very clear.
And I did fit the drum on and torqued it up tight (my torque wrench only goes up to 250lb/ft so I used the scaffold pole method)
A mention about an oil slinger washer, would this be the washer next to the bearing?
Now one thing I did notice was that the majority of leakage was not from the front of the bearing housing but down the backplate and with regard to this I am wondering if my fitment of VW backplates is the coloured gentleman in the woodpile. I'm running VW backplates because A) when I got the car/shell it didn't have any brakes and B) I'm running Fuchs wheels so I wanted the 5 on 130mm PCD to fit them. These backplates are new VW Heritage items but I don't know how their thickness compares to the 'correct' Porsche items.
Still oily and still in the dark.

[roy mawbey]

I can only presume the seal is correct, the seal lip has to be the right place on the spacer ring. The 356 back plate is 4.5mm thick. To get the compression correct you use shims they go against the bearing. You have to assemble the cover with seal in it and bolt up the unit then check with a vernier or possibly feeler gauge the clearance. From that result you can determine the number of 0.1 mm thick shims you need. Then the axial clearance of the bearing is controlled. The compression should end up at 0.1mm.

The initial set up goes :

1). Spacer ring with rad towards the back of the half shaft
2). Ball bearing
3). Shims ( to be determined )
4). ' O' ring
5). Spacer ring
6). Onto that spacer ring the rubber seal lip rests on.

The rest of then items then go on.

As the large 'O ' ring is around the circumference of the bearing For oil to be coming out from the back makes me think the oil is escaping from that area.

I have taken photo's of the factory manual and Elfrink pages that describe the job. Even the depth for the seal has to be controlled correctly. I have when young had axles apart but please do not take my advice as current. I know though or think I do, the oil thrower system was changed on 1959 cars and is more simple and the the pipe no longer used. Some one can confirm that??

A mix of parts VW / 356 might be the reason.

PM me with your mail address if you want my photos. You can I guess enlarge them then to read areas that are small.

Confusing you bet!!!!!

Roy

[Kneeslider]

My gearbox and rear axle is coming back from the gearbox shop in about 2 weeks, so I will be assembling all of this soon. I'm probably going to write up what I find on here, because I am not too sure about what to do at this point. Unfortunately I can't really see how it all goes together because I don't have the gearbox and axle tube combination to hand.

[simon james]

At the risk of sounding obvious, did you put the paper gaskets either side of the back plate???

[KS]

Just a thought... You're using VW backing plates and drums on the Porsche axle? I have a feeling the VW drum might have a centre (the splined bit) which is a different dimension to that of the correct 356 drum and maybe the axle nut is actually bottoming out on the thread of the axle, rather than tightening against the drum. If that's the case, then the axle won't be pulled up tightly against the seal. I think this is maybe where your problem lies – using VW drums/plates with the Porsche hub/axle tube/axle...

[Mike Smith]

Simon,

A 356 does NOT use the paper Gaskets - that is a VW thing

Also if you have paper Gaskets in your kit, it means that you have a VW Kit
If it is a VW Kit ? - the Large washer that goes against the Wheel Bearing WILL be too soft.

[Mike Smith]

Just a thought... You're using VW backing plates and drums on the Porsche axle? I have a feeling the VW drum might have a centre (the splined bit) which is a different dimension to that of the correct 356 drum and maybe the axle nut is actually bottoming out on the thread of the axle, rather than tightening against the drum. If that's the case, then the axle won't be pulled up tightly against the seal. I think this is maybe where your problem lies – using VW drums/plates with the Porsche hub/axle tube/axle...

I missed that - could well be the problem

Also it is necessary to Measure and Shim the Backplate – these are all the differences that make a Porsche a Porsche and not a VW

[simon james]

Hi Mike!
Yes, I know that.....
If you remember I bought two hub kits off you four or five years since as well as various shims and you even sold me a main-shaft castellated nut after I broke one when I re-built my gearbox after the diff cracked!
A couple of thousand miles later and still not a drip, the only leak on my car is off the rev counter cable!

I wasn't sure how much VW the car was rather than Porsche!

[Mike Smith]

I was surprised at you comment Simon - apologies for picking you up on it

At least you gave me the chance to bang away again how important some parts are --- and how little is interchangeable with VW

[Ignatzcatz]

Lots of great advice, thankyou. I shall do some measuring as noted but I put the verniers over the VW backplates and they were 4.5mm so no massive difference there. I do rather warm to Mr. KS's suggestion that the VW drum, which is a new VW heritage item might well be differing in the spline department and it might not be seating onto the axle as it should. This I shall also check out by assembling the drum alone onto the axle, but it smells right with regard to the amount of oil loss and the location of loss.
Unfortunately I'm off to buy a Cayenne tomorrow so I won't be able to get all oily again until Friday but I will report in detail then.
Thank you all again.