Cvs

[Buf-Phoon]

  XR6T8_U said:

Unless you race (1/4 mile racing) the car mercilessly then you should be ok...

Jack

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not necessarily so,in my 2003 T I buggered a LH CV within 24hours of having an APS Phase 2 fitted and this was with a softcock tune of 250+rwkw after only a couple of spurts Think I might have been one of the first if not the first to break one

[Max Power]

Another example of how youre not that good a driver. You should go in a group buy with Saleen on some logitechs

[Buf-Phoon]

Where did I say I was ... farking CS You are farked if I beat ya... too much chest beating before hand . I am not even at the track yet. Might have to race my Mazda

[Phoontastic]

  Buf-Phoon said:

not necessarily so,in my 2003 T I buggered a LH CV within 24hours of having an APS Phase 2 fitted and this was with a softcock tune of 250+rwkw after only a couple of spurts Think I might have been one of the first if not the first to break one

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Bugger. I hope that is the exception rather than the norm.

[HUSTLER]

  Quote

Should be out in 2 weeks

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Ive been waiting 2 weeks since October last YEAR!!!!!

[DAWSEY]

I did my drivers side one last week with 230rwklw!(400wrklw motor on run it mode)

it was a freak thing!!

my ball cage blow out and sent little ball bearings bouncing down the hill!!

was not good for the rexy behind me!!

lol

[F6 RAPID]

There is nothing worse than having your ball cage blow out..............

[bcl]

Below I post detailed pictures of the CV joints, how they fit together, and where they can fail.

The inner CV sits between the diff and the half-shaft, and quite a few people have reported failure.

The inner CV has 4 parts, the large cup, attached to the ½ shaft, and inside this cup are 6 ball-bearings, the cage, and the centre piece (I don’t know if it has a name), which is attached to the diff. This centre piece will move continuously as the suspension moves.

The 4 parts are below, pulled out of my car during initial evaluation.

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The groves in the cup show where the ball-bearings can move.

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If we place the cup on it’s side, then upside down: You can clearly see the splines as they fit into the ½ half shaft. This is a potential weak point.

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The centre piece sits inside the cage, which sits inside the cup, and the ball-bearings sits inside the slots in the cage, and between the centre piece and cup. Only one (not all 6) ball-bearings is shown in the picture.

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If you look at the inside of this centre piece you can see the slots where the shaft from the diff will slip. This is another weak point. I think it was Craig who reported that his CV was spinning freely, and this would happen if the metal fatigued here.

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Nizpro first had a strong cage created initially, as shown below. When people report that the cv’s exploded, and there were “ball-bearings over the track”, it is the cage that has exploded, releasing the ball-bearings. This appears to be the cv’s weakest point.

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New cv’s had just gone into the car prior to BVW1 for me to drive around in, and then a month later the cv’s were pulled apart. Nizpro had detuned the car for me to drive, as they were concerned about the cv’s. I was at Nizpro late last year just after they pulled the cv parts out of my car for inspection.

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You can see the crack that is starting to develop in the centre piece, with what was a brand new part after a very short time. This is an accident waiting to happen, and why my car won’t be driven until something much stronger is installed…. Still waiting!!!

Brian

[ktford]

Expensive little shuckers

[xlnt6]

Thanks Brian for supplying those pics, they certainly help.

Couple of things though, you refer to the inner CV (diff side), but the pics you show appear to be the outer CV (as apparent by the ABS tooth wheel). The info supplied is still relevant though. Most guys are smashing inner CVs, but it's interesting this one from your car is the outer ??

Also looking at the centre piece, you can see the fracture has occur at the stress points (namely where the circlip groove has been cut and more apparently where the ends of the circlip go - into an extra cutout), and it appears the machined groove for the ball bearings is depressed at the end nearest the circlip end, which seems to say that the ball race is getting to the end of it's lateral travel. This is a function of shaft angle, which is I assume is a consequence of lowered suspension ?

If the ball race is loading up on the edge of the grooves of the centre piece, it makes sense why this things are popping. I guess if Nizpro have made replacement cages, the next item would be to make a replacement centre piece, which uses a different circlip which doesn't require the "extra cutout" and is longer (in lateral dimension) to allow for additional travel and more shaft engagement. The cup section looks good and you can see the hardening treatment where the bearings go.

I guess time will tell what the ultimate solution turns out to be. I don't suppose you have any pics of the CVs at the other end to compare the mode of failure. Or is it the same ?

Cheers

Thanks again,

Robin.