So what did you do to someone else's 928 today?
05-02-2011, 12:51 PM
#31
Racer
Looks like a barber pole!
I thought only steel GM drive shafts twisted up like that?
So what are you going to do to prevent this in the future? 2x4 under the gas pedal?
I thought only steel GM drive shafts twisted up like that?
So what are you going to do to prevent this in the future? 2x4 under the gas pedal?
05-02-2011, 12:55 PM
#32
Supercharged
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We will be replacing it with an earlier model drive shaft (actually the whole Torque Tube) which has a uniform diameter. These late model drive shafts are necked down on the ends which we theorize concentrates the force right on the ends. The uniform diameter drive shaft distributes that force across the entire length rather than just the ends.
05-02-2011, 04:31 PM
#33
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No, Todd broke his and made a stronger replacement configuration years ago already.
When have you ever known any of those involved to only have one beer?
Keep in mind too that the GM drive shafts are after the transmission, so they have the torque multiplication of the transmiision that they have to transfer to the back of the car too. The 928 shafts only have to deal with the torque of the engine.
The current thinking as to the best solution using currently available parts is to use one of the constant diameter shafts and some way of preventing the shaft from pulling out of the coupling at the front. Some of the ways that people are currently doing that is by using more secure clamps, Loctite, or the clip design used by some of the earlier shafts. If you're using one of the constant diameter shafts, definitely do something to keep the shaft from pulling out of that front coupling. I think that using more bearings and bearing carriers to support the thinner constant diameter shaft would help too. To me it looks like Porsche went to the larger diameter shaft to try to fix one problem, and by doing so created another.
When have you ever known any of those involved to only have one beer?
The current thinking as to the best solution using currently available parts is to use one of the constant diameter shafts and some way of preventing the shaft from pulling out of the coupling at the front. Some of the ways that people are currently doing that is by using more secure clamps, Loctite, or the clip design used by some of the earlier shafts. If you're using one of the constant diameter shafts, definitely do something to keep the shaft from pulling out of that front coupling. I think that using more bearings and bearing carriers to support the thinner constant diameter shaft would help too. To me it looks like Porsche went to the larger diameter shaft to try to fix one problem, and by doing so created another.
05-02-2011, 09:19 PM
#36
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My thoughts
I'm no engineer, but that is what my line of reasoning was as well. Anecdotal evedence would seem to bear this out....and maybe a bad lot of shafts in late '89......
Good question.
We will be replacing it with an earlier model drive shaft (actually the whole Torque Tube) which has a uniform diameter. These late model drive shafts are necked down on the ends which we theorize concentrates the force right on the ends. The uniform diameter drive shaft distributes that force across the entire length rather than just the ends.
We will be replacing it with an earlier model drive shaft (actually the whole Torque Tube) which has a uniform diameter. These late model drive shafts are necked down on the ends which we theorize concentrates the force right on the ends. The uniform diameter drive shaft distributes that force across the entire length rather than just the ends.
05-02-2011, 10:18 PM
#37
Racer
A set of 4.11's would alleviate that problem, but would slightly hinder top end speed.
05-03-2011, 12:04 AM
#38
Rennlist Member
I dare you
It's available, but, I would strongly suggest you be sitting down and have a stiff drink ready.