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Brake drum and bearing question.

Posted: Mon Sep 19, 2016 2:34 pm
by Michael Haener
Hello All,

I am in the process of restoring my '58 A coupe and have been buying up new parts. Recently I ordered the wheel bearings for my car (early spindles) and without tearing everything apart first I just ordered the part number that was in my Porsche parts book. When I received the bearings (original Porsche part) I noticed they are beautifully made ball bearing race, but when I tore down the old drum I noticed I had tapered roller bearings in the car. The ball bearing races will not fit due to what appears to be a tapered bearing adapter being in place.

My car was built 4-15-58 and was off the road for many years, so whether these are original tapered bearings is anyone's guess.

My questions are twofold: first, should I use the ball bearings in place of the roller bearings? plusses and minuses? or just order the tapered bearings for the car. And second, if I decide to use the ball bearings, do I need to remove the tapered spacer that seems to be pressed into the bore to accept the rollers? best way to do that?

Thank you in advance for any input.
Mike

Re: Brake drum and bearing question.

Posted: Mon Sep 19, 2016 4:33 pm
by David Jones
Mike, are you sure you have the early spindles? Early spindles are LH thread for left side and RH for right and are held in place by double nuts with a lock plate. Later spindles are held in place by a clamp nut. Lots of cars had them changed out as the early spindles were prone to failure. My 59 "A" cabrio had one of each when I acquired it.

Re: Brake drum and bearing question.

Posted: Mon Sep 19, 2016 5:14 pm
by Michael Haener
David,

Yes, both are the early spindles (now) Interesting story that relates to yours: my car (early 58) also had an early straight spindle and a later tapered spindle when I acquired it. When I sent the spindles to Zims for a kingpin replacement I asked if they could make them the same so they were kind enough to swap my later for an earlier, which is more "correct" for my car. I had always thought that somewhere along the line the car had a spindle replacement, but now hearing your story I'm wondering is some cars had mismatched spindles.

Anyway, I think I figured this out - the part inside the hub is the inner race of the tapered bearings and needs to be removed whether I go tapered roller or ball bearing. I see reference in the workshop manual to heating the hub to 175 degrees and driving out the inner races, so I'll give that a try. The hub is in the oven now :shock:

I'll probably just use the ball bearings since I already have them and they seem to be more correct for my car.

mike

Re: Brake drum and bearing question.

Posted: Mon Sep 19, 2016 5:36 pm
by Jon Bunin
MichaelHaener wrote:I am in the process of restoring my '58 A coupe... My car was built 4-15-58...
Mike, based on the production date, your car would have been built with early spindles.

Re: Brake drum and bearing question.

Posted: Mon Sep 19, 2016 6:33 pm
by David Jones
Interestingly my cabrio was built according to the C of A on September 1st 58 so it is I guess possible they were using up old parts still on that date seeing the sept 3rd date on the bulletin.

Re: Brake drum and bearing question.

Posted: Tue Sep 20, 2016 12:10 pm
by Brad Ripley
Jon, thanks for posting that bulletin. It's clear when they started with the later spindles for Carreras. But from the second and third "All 356A types" would indicate that initially supply was not up to car production and that some cars got the old spindles. As for exactly what day ALL cars got the late spindles, that might be a little iffy in my mind.
However, I think we can conclude that into Sept '58 all cars got the late spindles.

Re: Brake drum and bearing question.

Posted: Fri Jun 16, 2017 8:17 pm
by David Pateman
David Jones wrote:Interestingly my cabrio was built according to the C of A on September 1st 58 so it is I guess possible they were using up old parts still on that date seeing the sept 3rd date on the bulletin.
That is one reason why you have to take COA or Kardex dates with caution. The Kardex dates are Invoice date and date of Sale to customer, and the COA date would be one of those. So, these dates can be weeks after the car was on the production line. The bulletin date would be the actual production line date. It is actually quite rare to get a true production completion date at Porsche.

Re: Brake drum and bearing question.

Posted: Fri Jun 16, 2017 8:42 pm
by David Jones
David, Sept 1st would be very soon after the traditional summer break that was standard for most manufacturing companies in Germany at that time. When production resumed in July/August was when the new models were introduced so it was as you say entirely possible my car started life in July/August depending on date of end of summer break. How long one wonders did it take back then to make a car from start to finish? Were cabrios built alongside coupes?