Bearing crush sleeve crush

[tadd]

Might anyone have a 'spent' 930 bearing crush sleeve they could measure? The new on in my hand is 37.25 mm. The back sides of the inner and outer race measure equal heights (bearing down, race backside up).

I'm trying to get a feel for the distance between the back sides of the two races. I've machined two 'bearing holders' out of 1018 to accept the larger inner 930 bearing. I will then weld these to an early SWB steel banana after trimming material so I get the correct spacing. It's all madness to put 934 center locks on my 67 . The outer race is darn close and either the banana bearing seat will get a mm larger in diameter or the local bearing house will chase me up a new bearing to match, ID but hair smaller OD.

I took a stab at measuring inside an aluminum turbo banana, but is not an easy measure. I got close to 36 mm. A 1.25 mm length change in 37.25 mm doesn't seem too bad at 3.3%.

Thanks in advance...

t

[66cal912]

If you can wait until tomorrow night, I have a couple used ones that I can measure for you, I think your not far off on the crush, But Id go by the spacers. They are a ***** to get set right, You need to use a dial indicator, along with a very accurate click 3/4 drive torque wrench. Its easy to overshoot the torque and bearing free play, trust me I ve done it, :-O.. I would almost go with a hard crush sleeve over the Porsche collapsable ones at 100 bucks each. And use an inch pound needle torque wrench like on a pinion gear set up to measure resistance torque, which Porsche gives values for in the 930 manual..

Nice project though your doing using the steel arms, Id be surprised if the 930 sized bearing fit tnat, even machined out, I ll have to look at the sets I have just for curiosity...

Good luck, Ben

[tadd]

Ben:
That would be awesome. No screaming hurry . Busy getting the tub off for paint at this instant. I'll take a few pics once I get the banana on the mill. I made a top hat shapped block that spiggots into the outer bearing race seat on the banana. That uses the four holes to bolt to the banana, then the whole unit goes on the table, arm sticking up in the air. I then need to feel for center on the too small inner race. I'll then plunge cut some amount into the old inner too small race (about 1.75") with a 3.5" shell cutter. This will cut back to just about the caliper ear. I have already turned a 'bearing holder' on the lathe that accepts the bearing and seal that will be located with a press fit aluminum pin and welded into position.

So I just need to know how deep to cut...

I'll get pics as I go if your interested. I haven't got the iPad picture post thing sorted yet .

[66cal912]

I found these pics a while back, I think on some German site, and they looked well made replica's of original '73 Short arms for RSR. Look well made with a bigger bearing than a normal steel arm, but not the same bearings as a turbo, using the two sided cone bearings and crush sleeve...


Might give you a few more Ideas...