Need help - Worn hub or wrong angle in hub ???

[Christoph]

I need your help !

My Tudor had very bad worn brakes
(welded studs, turned out way to much,
not round = full package)

Annoying: allways needed japanese
cars to come to a stop

So i bought 4 "Model A rebuilt cast iron brake kits"
at a big vendor.

Due to distance, i got to buy outright
(no exchange)

3 of them were easy to install, one (left rear)
moved in (on the axle) far to much
and drum collided with back-plate and brake
shoes.

I retried old material and found
axle-hub-mounting perfekt ok and for sure
I DIDNT HAVE TO USE SHIMS ON ORIGINAL TRIM.

I shortened the new drum
and got to use shims with new rig.

Brakes work perfekt now
BUT


Shims show wear every some-hundret miles
Axle-key shows wear now (one year and four shims later)
Flute of axle-key in the hub shows wear now.


What now??
Got to buy another new Brake kit (685.- Dollar +transport) again??
Might axle be cause of prob (even old rig did fit like glove)??
Is axle damaged now too (even it looks ok)??

Any suggestions are welcome.

Thank you
Christoph

( I guess its not my skills that one out of four doesnt fit ?)

[Pilotdave]

Cristoph, sorry to hear about your challenges. Mostly all I can do is sympathize, but I know there will be some help coming on here. Do you have pictures of any of the old or new parts in their 'before install' and 'after install' conditions? Have you spoken with any of the technical people at the parts sources? I think these guys are often overlooked as a source of info.
Thinking about the rear hub sliding onto the axle....unfortunately I don't any access to any parts where I am, but it sounds as though something in the new brake kit involving the hub, drum and bearing is different from the old. The one part that hasn't changed is the axle. Can you compare the old and new parts and see if anything looks different? How about the pitch of the bore in the old and new hubs?

On the axle itself, is the keyway damaged? Any grooves worn into the axle by a poorly fitting hub? Whatever is causing wear to the key and the 'flute of axle-key in the hub' is NOT your friend. I might start with a parts catalog showing an exploded view of the hub and axle and see if you can account for every part that is supposed to be there. Finally, what are these shims that you mention?

Sorry to ask so many questions without some specific ideas as to the cause of the problem, but something is allowing the new hub to slide too far onto the axle shaft....gotta pinpoint what that is. Good luck and let us see pictures and hear how you are making out.

Dave

[juke joint johnny]

Christope ,Did you buy 4 rebuilt hubs & drums ? It sounds to me like the drums were new cast iron ones on rebuilt hubs. i think the taper on the problem hub is oversize, allowing the unit to hit the back plate etc as it goes on further . Thats why you need all those tapered shims, which are not really a good idea in that quantity .As you tighten the hub those shims work there way up the axle shaft. I found one inside the axle housing on my truck when I rebuilt it.After a few miles it all works loose again , and will damage the axle shaft hub etc. I would clean up the axle shaft , and take the new cast drum off the bad hub and fit the drum on the best original hub you' ve got [ hopefully you kept the old parts you took off ] That way you only have to buy some new studs and possibly a hub bearing and sleeve. If you don't have a hub to use pm me I might have one.
John

[Don/WI]

If Iunderstand correctly, you bought new cast iron drums with the hubs installed. If that is true, switch the right wheel assembly with the left and see if you have the same problem on the same side. If you do, then the problem is your axle shaft. If the problem moves with the wheel assembly, the problem is the taper in the drum/hub assembly that you bought. If that is the case, the supplier owes you a new or good used hub. Let us know what you find out. Thanks and good luck. Don/WI

[Kurt in NJ]

to me it seems that the taper in the hub doesn't match the taper on the axle, it's the taper not the key that is intended to transmit the power, I have lapped the hubs to the axle before to both check the fit and ensure full contact using fine lapping compound

When the taper doesn't fit the key takes all the work over and in trying to do the tapers job it wallows around and gets beat up

Did your new drums come with new "repro" hubs, or were they put on old hubs?

Post some pictures ---old hubs showing welds, new hub showing inside of taper, taper part of axle

[Christoph]

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Thank you for all of your help and input!!!

First of all i learned something new:
Angle inside the hub is to be called taper

I guess its even good once others reflekt things.

@ Dave.
Ja - i got to have a much closer look onto things in future. Even i think
that speed of my work went down over the years i got to take even
more time to have a look .

@ Johnny and Don
I bought everything assambled and i guess (cant remember) i got used
(old) hubs with new drums installed on them (wasnt offered with NEW
hubs back than?). Why i bought all assambled is, that after assambly
the drums need to be "turned true" (move equal to the hub). To turn
them true you need to fix them on a turning-maschine and no maschine-
shop over here has the taper to fix that. Maybe they just wanted my
money but it allways sounded like : "well -we will need to built a bracket
first" which sounds expensive to me.

Right drum wont fit on left side as i got to chop a slide of the left drum
to make it fit. Just 3mm (sorry, still german measuring). Old drum was
chopped too which seemed to be no big deal at the time. Prob starts
in the axle as free end of axle is 2mm shorter on left side than on right side.

(Destroyed shims are sharp (Autsch) and i guess they will ruin bearing too).

@ Kurt
Ja - everything you say is true and fits to what i learned way back in time.
(got old hubs i guess; as mentioned above)
Nice thing is lapping till things fit together.
Hard thing, as without shim the hub wont fit onto axle or would run into
back-plate (no way to lap).....

Will do pics soon and will be back than .
weather is bad - no way to demount in the rain (german private-
garages are way to small to work inside).

but i guess - Even on pics is no way too see if (or if not) the taper
of the hub will fit onto the axle.....

Ja - the key wallowed arround and key and hub seem to be gone.
Axle looks good - seems to be much harder than the hub???
hopefully its ok as i dont want to demount the axle
(please no)


Once i press old drum from my old hub and attach to new drum on my old
hub, i would have to get it turned true again ?????? bad idea...
Im back where is started.

Further suggestions are very welcome

Thank you for your help
Christoph

[Christoph]

and i even did not do enough pics back than (4th of April 2011)


pics are :
left pic - new front brake
middle pic - right rear brake
right pic - old and new front brake

no pics of the left rear (need to look into my other pc)

[juke joint johnny]

Christope
How much end play have you got in that axle shaft? Can you pull on that axle shaft and move it in and out ? If there is much movement , that is where you're losing your 2mm or more . You might have to take the axle apart to get rid of the free play, If the old hub and drum will fit on without all the shims I would put that on untill the weather improves and you are able to look at the rear axle. You don't want to damage that axle shaft, it looks a bit chewed up in the photo.It's expensive to replace.Try the right hand drum on the left hand side if that will tighten up without shims then the trouble is in the axle and not the new hub and drum.
I hope this helps
John

[Kurt in NJ]

the coloring of the end of your axle makes me think it is "working"=moving-the rust color area probably doesn't fit the hub properly---the metal grindings make rust dust

if you change the drum on the hub it needs to be turned again ---if you can find a place that can turn an old VW rear drum perhaps they can do the A drum

swapping drums to see which is the problem is a good idea

[jimvette59]

Your axle is shot. The drum and axle should be a matched taper fit. The drum should seat tight on the axle with no key and be difficult to take off. You need to " BITE THE BULLET ". Any hub you put on that axle will get ruined. JMHO

[Christoph]

@ Johnny and Kurt
Thank you for your ideas. Due to nice weather i left work and did more investigation
and lots of pics.

@ Jim
Ja - Shocking thing is, that 3 hubs fit as they should and one does not !!!!

@ All
Have another look on my pics and please post your ideas!

First pics: Old left rear
1) best out of 4 (only old brake without welding)
2) inside nothing special
3) outside - is old and looks old

[Christoph]

next 3:
4) Taper in old hub looks good
5) Drum was turned (shortened) see -turnmarks
6) all other old hubs are welded (good, that i dont need them anymore)

[Christoph]

next 3:
7) old left rear drum and old right rear drum (very different)
8) new left rear outside
9) left rear axle (still looks ok)

[Christoph]

next 3:
10) new hub looks ok from inside BUT
11) new hub looks BAD from outside
12) key in axle still looks good

[Christoph]

next 3
13) shim with 25 miles on it
14) new left rear (on left side) old left rear (on right side)
15) i shortened the new drum with a side grinder (very farm-fix )

[Christoph]

next 3
16) old hub mounted today - fits like glove again !!!!!
17) old drum enough space to the back plate
18) need to use device to demount old hub (never need that for new one !)

[Christoph]

last pics
19) new hub with shim slides in much more (than old one does without shim - no pic)!
20) new hub mounted with shim! see that screw nut is much more screwed in, as on old hub seen on pic 16

[Christoph]

Im pretty sure now, that "new" hub is BAD !
Sad, that vendor uses rotten hub to mount new drum
and parts and puts in lots of work and pride
while turning true....

I cant send that back to US as shipment and taxes are
more expensive than putting it to the junk.

What do i do now?? Remount one old drum again
(just left rear)??

please send ideas

Thank you

best regards
Sad Christoph

[J Franklin]

I would as suggested find a brake shop or machine shop that can do the VW hub/drum combo. There must be one in Germany! redo the original hub to the new drum. You may need to purchase new studs (for cast drums). This might be your least expensive replacement option. I have use the shims successfully, with a bit of lock-tight type bonder on clean oil free parts. never lubricate the hub-axle connection. This may work for you also. the shim should not move if the installation is done correctly and the finished job is tight. the axle nut is tightened to a high torque value that you should determine as I don't know it off hand. Good luck.

[Christoph]

I remounted "new" hub and drum again with carefully attached
new shim an tightened to high value torque (which i dont like)....

Might work but i guess taper of new hub is tooo bad.

Will figure out how to get new drum onto old hub.
Not to much "good" machine shops left here
(i guess this is similar to US)

20 years ago - no prob, but now????

Ja - i guess i have to put new drum onto old hub.

new combo will be turned-true again and new shoes wont fit as good
anymore but - ja - you are right - its best solution.

cant i save new studs ? how to demount them?

Thank you Christoph

btw
Beetles are "away" from the streets over here,
and i guess most beetle parts come from US nowadays