Bri Bro

We will get a part number for a Porsche part that is not listed or stocked!

I have found two numbers so far for the Torque Tube bearings;
First one from Greg's Home, 928 Tips:
6006 2Z C5 HT51
Where 6006 is the series (metric), 2Z is a double shield, C5 is the running clearance, and HT51 is high temperature grease.

The running clearance goes from C1 to C5, with C1 being the lowest and C5 having the most radial clearance. My supplier stocks C3 for electric motors and they run $10, he doesn’t stock the number above. He stated that the application for the number above was in a high temperature, high speed application. The C5 bearing allows for the most expansion with heat. The double shield allows the bearing to be used in high temp and high speed application.
<a href="http://www.skf.com.mk/skfnews/Stainless%20DGBB.pdf" target="_blank">http://www.skf.com.mk/skfnews/Stainless%20DGBB.pdf</a>
Maybe some torque tube rebuilds use the 6006 C3 which is a common bearing in the bearing supply world. This could explain the reason for the rebuilt failures.

Second number from a Rennlist search, I think this is from your write-up Martin:
6006ZB C4
The 6006 is the series but I can’t find a cross to the ZB, I guess this is also a double shield number.
Here is a cross of the different supplies.
FAFNIR 9106KDD
MRC 106KSFF
NSK 6006-ZZ
SKF 6006-2Z
NTN 6006-ZZ
The C4 also has a tighter radial clearance then the C5 and there is no reference to the HT51 grease. The standard grease is rated at 230 DegF and the HT51 is rated at 287DegF. Note that SKF doesn’t list a C5 option.
<a href="http://www.eis-inc.com/oem/catalog/pdfs/bearings/SKF.pdf" target="_blank">http://www.eis-inc.com/oem/catalog/pdfs/bearings/SKF.pdf</a>

Does anyone have access to an ORIGINAL torque tube bearing? The number should be stamped on the bearing.

BC

I have just rebuilt my TT. But it was my *928* TT. I understand that you guys are trying to do some homework before you take yours apart, but you will want to make sure it is a 6006. Our 928 shafts are 6006 ot 6007, depending on the year.

Do you know if the shaft in the 944 TT is the same size? Has anyone checked?

FYI - the bearings orgininally are merely "shielded" - but I purchased "sealed". ANd a very good brand, so I expect longevity.

When puting the beaing carriers back in, simple green works like a grease that will evaporate eventually. Also, you will need to unkey and then rekey the inner bushings on the bearings themselves, if Porsche did the 944 the same way.

Bri Bro

Brendan, do you have a source and a part number? All 944and 951 use the 6006 to the best of my knowledge. It is a pleasure to get a response from the 928 folks.

BC

Beab -

I purchased from A&W bearing. I was told I should have just gone somehwere locally, but it is easier for me to do it this way. Prompt shipping.

<a href="http://www.awbearings.com/awbearings/directorydb.asp?Brand_Name=NTN&Part_Number=6006&product=B&x=8&y=13" target="_blank">A&W Bearings</a>

That link there brings you to the 6006 bearings list. The LLB means double sealed, but other manufacturers will say different letters for the same thing.

As you know, the C3 and C5 are clearances. I got C3, with the double sealed version. I actually have one 6007 and three 6006s sittinghere on my desk, as I have to return them. As I mentioned, I ordered 6006 because thats what a writ up on the rebuild of the 928TT said, Well, the TT that I purchased for my 81 928 auto 3spd to 4spd swap was an 89 - and that was a year that they switched to a LARGER shaft diameter. Oh well. The story is that the 4spd is obviously very different from the 3spd, so I hade to change alot of stuff. To save some money, I rebuilt the TT. Ours are 495. Don't get me started....

Anyway, if you guys have those carriers that have to be separated, then this is a harder job than what I had. Just make sure you put them together correctly, and if you have inner bushings like we do, then you must make sure you put the bushings in the correct direction, and "bang" or "key" them as they are originally, so that they will not slip out.

Bri Bro

Thanks for the Link Brendan, I found a SKF number 6006 C4 ZZ HT that looks interesting, I will call them tomorrow.

<a href="http://www.awbearings.com/awbearings/dbinfo.asp?key=728837&Product=B" target="_blank">http://www.awbearings.com/awbearings/dbinfo.asp?key=728837&Product=B</a>