993/964 distributor bearings possible solution

[crg]

i went through this same nut roll earlier this year, the correct bearings were a b*tch to find.

you'll need 3 each- FAG 7201 BE 2RS AH01 (same as the INA 7201-BE-2RS-AH01)

i was able to find only one guy on the entire planet who has these:

dirk.schluecking@dswaelzlager.de

165 EUR for the three AH01's

you'll also need one INA NX12-Z.... I picked this one up locally

good luck!

[Traveller]

Originally Posted by crg

165 EUR for the three AH01's

Thats about US$205 (CA$240) and a far cry from the $420 (CA$490) quoted in the US.

It was that or nothing in the case of the one I rebuilt for a local owner. His bearings were gone at 112,468 miles (181,000 kms)!

[Al S]

Originally Posted by Traveller

Al, just out of curiosity, did you remove some of the shims to reduce the side load on the ball bearings that the Belleville washer puts on them.

Alex, dang it, it's been a while, but there was nothing removed.
Didn't see the need..

[RedCoupe]

Originally Posted by Traveller

Al, just out of curiosity, did you remove some of the shims to reduce the side load on the ball bearings that the Belleville washer puts on them.

I took my distr apart a couple of years ago to change the belt and check the bearings. Bearings were still fine at 130k, but I couldn't get it back together without a press because there was so much preload. I left a couple of the shims out and it still had zero end play. Cars got another 15k on it with no problems.

[Traveller]

Originally Posted by RedCoupe

Bearings were still fine at 130k, but I couldn't get it back together without a press because there was so much preload.

There seems to be quite a range in mileage-to-failure.

When I look at the distributor I just rebuilt, the insides didn't have a hint of rust on the parts and I mean it looked like it came off the assembly line yesterday, yet the bearings were rusty. Go figure!

Yes, there is quite a bit of preload on the both the primary and secondary shaft bearings due to the Belleville washer, which is why I would not use a ball bearing. A ball bearing does not take side loads well which is why I asked Al a few posts up if he had removed any shims to reduce that load.

Originally Posted by RedCoupe

I left a couple of the shims out and it still had zero end play.

The angular contact bearings need some preload. You can use a drill press with the jaws turned in as a make-shift press.

[Traveller]

Originally Posted by crg

I was able to find only one guy on the entire planet who has these:

dirk.schluecking@dswaelzlager.de

There are a few bearing vendors that have them but Dirk is who we got the last set from the other week that I installed on a local owner's 993.

I just ordered a set for myself from Dirk, but had them shipped to my Euro address for pick-up there. I just wanted to make sure that source didn't dry up before I had a chance to get some spares.

I'll be picking up a slew of them when I am there next summer. He is 8 kilometers off the Autobahn I take every summer.

DS Wälzlager & DS Sports

[sand_man]

Really great info! Thanks for all your efforts!!!

[briefescape]

Originally Posted by Al S

This cheap fix was done 5 years ago, and many many miles later - still going strong!

Still enjoying the $17 bearing fix 40k miles later . Al is your friend ( mechanic ) if you need work done in the Lower Mainland BC . Best thing you can do for your Porsche maintenance service is to get hold of AL .

Cheers Guy

[Al S]

Originally Posted by briefescape

Still enjoying the $17 bearing fix 40k miles later . Al is your friend ( mechanic ) if you need work done in the Lower Mainland BC . Best thing you can do for your Porsche maintenance service is to get hold of AL .

Cheers Guy

Guy, thanks for the plug!

[Traveller]

Despite available make shift solutions, I'm glad the original bearings are readily available now. I got mine in a few days...

[efhughes3]

I'd say the credit goes to Jason for the source of these:

Accidentaly rotated the dizzy rotor when replacing. Am I OK? - Rennlist Discussion Forums

[sand_man]

Originally Posted by Traveller

Despite available make shift solutions, I'm glad the original bearings are readily available now. I got mine in a few days...

So to be clear, these bearings (#7201....) are the "correct" replacements? No milling or shimming? My car has only 77K on it, but I'm planning to service the dizzy around 85K, maybe sooner, just for kicks.

[crg]

yes they are the correct bearings and assuming you want to replace ALL bearings.."you'll also need one INA NX12-Z", it's a needle combo bearing inside the bottom end of the primary shaft housing.

[Traveller]

Originally Posted by sand_man

My car has only 77K on it, but I'm planning to service the dizzy around 85K, maybe sooner, just for kicks.

The dual distributor I just rebuilt for a local had 181K km (112K miles) and his bearings in the secondary were locked which is why the belt snapped. Some owners have gone further and some less.

We, or at least those interested all knew what the bearing part numbers were, but if you Googled that part number a few years ago, you came up with nothing other than links to other forums searching for them as well. I have to give credit to those suppliers hunting down a source and there are a few of them in Europe. Schaeffler North America is clueless/tight lipped about them for some reason, but I'm not letting them off the hook.

[Traveller]

Originally Posted by crg

you'll also need one INA NX12-Z...

Is there any reason why you went for the NX12-Z over the NX12?

The NX12 is for oil lubrication and the NX12-Z for grease lubrication according to INA.

I can't tell the difference from their on-line drawings. As for lube, of all the ones I have taken apart, I never found a hint of grease in that area, but they were all well oiled.

[crg]

i replaced what the factory had installed, the part number was clearly visible

"As for lube, of all the ones I have taken apart, I never found a hint of grease in that area, but they were all well oiled."

I'm dont see why "oil" would be inside the primary shaft housing? or how it could get in there? the only piece of the dizzy that should see oil is the gear on the end of the primary shaft as it's engaged with the drive gear on the crankshaft...if go back to your first photo, the INA needle combo bearing is the one on the end of the primary

[Traveller]

Originally Posted by crg

I'm dončt see why "oil" would be inside the primary shaft housing? or how it could get in there?

I checked my new-old-stock dual distributor yesterday and there is a gap between the housing at the bottom and the bearing...I was able to slide a white project board piece of cardboard between them, so there is a gap for splash oil to get there and then into the holes at the base of the bearing at the sides.

I found this pic on a 993 forum from a member that rebuilds them. Of course I'd like to confirm that myself.


And then these pics on a bearing manufacturer's site showing the differences...


Not a pressing issue since that bearing is fine in all the distributors I have taken apart, but let me do some more digging.

[Nine9six]

Join Date: Mar 2006
Location: Moorpark, CA 93021
Posts: 1,124
Garage
The bearing I'm trying to use is a SKF for a VW alternator. My machinist said he cannot grab the shaft good enough to comfortably turn it, so he is building a jig to hold the bearing and will get or make what he needs to machine out the ID of the bearing to fit the shaft. If he can successfully do it, I'll probably give him a bunch more to do, and start selling them!

The bearing would be much better ID ground, as opposed to machining. Holding force would be significantly less as well.

Sounds like your machinist isn't thinking clearly.

[martensson]

Just a question regarding the bearing above.
The 7201-BE-2RS.AH01 has the following measurements, 12,45x32x10mm

The 7201-BE-2RS in the quoted post has 12.4x32x10mm

There is an id difference of 0.05mm. Is this bearing still possible to use with no modifications or even heating bearing & cooling shaft?

[Traveller]

Originally Posted by martensson

Just a question regarding the bearing above.
The 7201-BE-2RS.AH01 has the following measurements, 12,45x32x10mm

The 7201-BE-2RS in the quoted post has 12.4x32x10mm

There is an id difference of 0.05mm. Is this bearing still possible to use with no modifications or even heating bearing & cooling shaft?

Fits perfectly having installed a few.