whpracer
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| posted on 2/9/07 at 07:16 PM |
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propshaft problem
I have a serious problems with the locost.
the diff flange and the sprocket flange are not parralel. ( see pic ) the first propshaft with UJ made huge vibrations on high speeds.
because I cant's get the engine flange parralel I decided to make a new propshaft with 2 CV joints. Both joints are normal tintop type's (
vw ). with the first testdrive de cv boot of the middle joint exploded due to running agains the frame at high speeds. I replaced the CV boot or a
aftermarket type ( universal) witch is smaller in diameter. but for some reason it began to leak at +/- 60 mph. For some reason there is a little hole
in the boot .
It ran free, the working angle is 13 degree. it does run at high rpm, at top speed it could make 9400 rpm.
is this prop shaft any good ?
can a cv joint take this high RPM ?
how did it come that the boot began to leak ?
any comments welcome
[Edited on 2/9/07 by whpracer]
[Edited on 2/9/07 by whpracer]
[Edited on 2/9/07 by whpracer]
 
Rescued attachment prop.jpg
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Bob C
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| posted on 2/9/07 at 09:54 PM |
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props spin much faster than driveshaft CV joints normal application. However some road cars used a CV joint in the prop - the one I know for sure is
the rover SDI - that (& its boot) ought to be engineered for high revs
Bob
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MikeRJ
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| posted on 2/9/07 at 09:55 PM |
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CV joints are unlikely to take that sort of RPM...or at least the rubber boots aren't.
Was your orginal propshaft a two piece item with an intermediate support bearing?
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ReMan
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| posted on 2/9/07 at 09:57 PM |
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No expert, but I reckon you have 2 or 3 problems here, definatly need some more (proffesional) help
I would have thought you need a centre bearing at the angled joint?
The angle 13deg is much to high imho, especially at those speeds?
imho you should have engine and diff flanges as parralell as possible to prevent vibration due to phasing of the joints
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Bob C
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| posted on 2/9/07 at 10:18 PM |
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There's tradition of tricky propshaft routeing in the '50s front engine, rear drive GP cars. At the time it was the achilles heel of the
lotus 16 (I think) but the model does very well in historic racing using mini CV joints made by rzeppa. (the works team had swapped to rear engined
18s by the time these became available).
I get the impression that the 1st poster's CV jointed item works fine but can't keep its grease in!
Bob
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James
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| posted on 3/9/07 at 09:32 AM |
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On my Mk2 Golf, the GTI spec' CV joints have a hole in them for the purpose of (I believe) venting hot air built up as the car runs and the CV
joints heat up.
HTH,
James
[Edited on 3/9/07 by James]
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"The fight is won or lost far away from witnesses, behind the lines, in the gym and out there on the road, long before I dance under those lights."
- Muhammad Ali
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