924Board.org

Karlio · Joined: 17 Nov 2019 Posts: 99 Location: UK

Apart from Black Sea R&D who does replacement torque tube bearings for 924 n/a?
And if you were to build a new torque tube out of aluminium tube what thickness wall would be recommended?

Cheers karl

morghen · Joined: 21 Jan 2005 Posts: 9044 Location: Romania

Bearings are standard size as far as i know and i’ve heard of people using off the shelf bearings in their rebuilds.
The parts that are tricky to find are the plastic bushings that go in the centers of the bearings and rest on the torque shaft.
These you could find made by a Slovenian guy some years ago but i havent seen him around lately.
I have the drawings for these so i may try to make some.
The truly tricky bits are the outer ruber bushings that go on the outside of the bearings and rest on the inside surface of the torque tube.
If i’m not mistaken these are called vibration dampers and people re-use them or if they are dead they take them from other TTs and make a good set.
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Supercharger and EFI kits
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Karlio · Joined: 17 Nov 2019 Posts: 99 Location: UK

Have a shuftie at www.blackseard.com for the uprated bearings, they come complete.

Karlio · Joined: 17 Nov 2019 Posts: 99 Location: UK

And this is a terrific tutorial on removal and replacement

https://youtu.be/YueDw_2i7ns?si=p5jbykZNmEG3Q9pp

morghen · Joined: 21 Jan 2005 Posts: 9044 Location: Romania

Really cool stuff!
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Supercharger and EFI kits
https://www.the924.com

safe · Joined: 18 Mar 2017 Posts: 671 Location: Sweden

I bought bearings and carriers from a Danish guy on Facebook. He sold the bearings or complete replacement torque tubes. I think it was info@9werk.dk, he doesn't seem to have any products on his website anymore.
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/Magnus, Stockholm Sweden
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Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

Karlio · Joined: 17 Nov 2019 Posts: 99 Location: UK

Any thoughts on wall thickness for aluminium tube swap?

ChrisMadge · Joined: 16 Dec 2020 Posts: 29 Location: Bristol, UK

safe · Joined: 18 Mar 2017 Posts: 671 Location: Sweden

morghen · Joined: 21 Jan 2005 Posts: 9044 Location: Romania

daniel · Joined: 18 Jun 2009 Posts: 678 Location: Sydney, Australia

Carrera's had a alloy tube if I remember correctly. See if you can find any specs.
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Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet

peterld · Posted: Sun Mar 03, 2024 11:21 pm Post subject:

IIRC, Mike9331 here on the Board made an alloy torque tube.
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80/81 932/8 ROW

jacobroufa · Joined: 18 Nov 2016 Posts: 531 Location: Belvidere, IL

Mike did make one and last I knew it was fitted to one of his 931s.. It was quite a process; maybe he can chime in with the latest updates!
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1980 Porsche 931
1981 Porsche 924 Weissach

chuck21401 · Joined: 20 Feb 2005 Posts: 573 Location: Annapolis, MD

Mike9311 · Joined: 14 Dec 2004 Posts: 1793 Location: Chicago-ish

Hi Everyone

Apologies for being such a terd and not being around here. Life has just really been busy and it kills me just to come check things out here when I am not getting my hands dirty myself. Well they do get dirty just not on a 924

(getting started again on the heads stuff too)

I need to get the exact specs for this but Morghen's 6mm is about right

Originally posted here in this thread. This is for the S2 81+ Audi Trans but I am working on a S1 version that is roughly half done already. With the right shafts the tubes would work for NA set ups as well. This car is actually getting worked on right now

Hope to make more progress today and get it off the lift shortly

https://www.924board.org/viewtopic.php?t=42087&postdays=0&postorder=asc&start=45

As you scroll down through the pics I'll make some more comments. I am sure I'll miss something along the way but I'll post more

You need a secondary tube welded in this flange after boring out the steel portion. This is not the actually tube section here but a step to help match up to the flange

Now I have developed new rebuildable bearing carriers. In this way I could control my fitment by controlling the durometer of the rubber used and in some ways hoped to increase the stiffness of the system. The bearings are the more commonly available C3 internal clearance rather than the C5 looser internal clearance tolerance originally spec'd. I have lots of thinking as to why things were done and spec'd the way they were on the original parts. For one thing the original torque tubes lined up in a lathe between centers are never straight. This could be why they used sheetmetal based carriers that could deform a bit to adjust to any irregularities. My carriers are also designed to adjust slightly but internally rather than by the body flexing. It does appear that you could use stock carriers in the Al tube as well. I also do not believe in larger bearings. These bearings need to spin up cold and additional inertia isn't helpful. Why plow larger balls through cold grease? Plus the weight? They are just there to keep the shaft straight.

Internally they don't look like this anymore. These are just old prototype pics

The S1 tube is ready as well as the engine side flange. Just working on the final version of the trans side flange.

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1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car