jkstill

iTrader: (11)

I've heard of drag racers breaking Axles, but have not until now heard of breaking CV joints.

My FD is autox only. It had been making some noises I had not been able to track down. In particular there was an odd high frequency vibration in high RPM's in 2nd gear.

A few weeks ago on a test drive around the block there was a loud high pitch squeal when turning left, but that noise went away and I could not reproduce it.

At an autox last week the left side inner CV joint gave way while making a sharp fast left.

The CV boot did not leak and the joint was not dry. This was a used axle that I had installed, as the original is permanently stuck in in the upright, and was damaged by removal attempts. (The studs were being replaced)

Two of the bearings in the inner CV joint had come apart, one of them was broken. The remaining one was disassembled by me.

The used axle was installed early last year and seemed OK. I can't recall just when the odd vibration started.


Anyway, there was no visible damage on the boot, and I'm wondering if anyone else has seen this kind of damage, and/or has any idea what may have caused it.

jkstill

iTrader: (11)

Well, week later, 129 views and no replies.

I think this broke because I didn't put enough spring in the rear.

The suspension has bottomed on a couple of bumps in right turns under acceleration, and I think that is what the damaged it.

How much spring?

750 lb.

I just installed 850 lb springs to try and cope with it.
Probably I will increase the spring rate a little more drastically all around over the winter.

billyboy

Seems like a lot of spring. 750 lb is commonly used to cope with a 250kmh corner over here with slicks.

Tripod joints can be killed by over-articulating, I think there's a 7° limit from memory. Hard to say whether it's needle rollers disintegrating or wear and tear, witness marks going to the edge of the housing might suggest something is over travelling - maybe.

Axle/upright/CVs/tripoidal joint assembly swapped in or just the axles and if so, not an inadvertent swap side to side?

jkstill

iTrader: (11)

Really that is barely enough spring to cope with R compound tires in autox.

The entire assembly was swapped, it may have already been damaged.

As for swapping left to right, why would that matter?

The parts as sold by Mazda do not come in left/right part numbers, they are all the same.

billyboy

Lots of people have found to their chagrin, you don't get used axles and then expose them to force reversals to what they've experienced in prior use, not an issue with new. Joints tend to develop wear patterns too, so was thinking of that possibility - which doesn't appear to be the case with a straight swap.

jkstill

iTrader: (11)

I suspected that was what you were referring to.

Unfortunately when buying used axles it is often impossible to know which side of the car there were originally installed on.

Buying new parts from Mazda is not really an option, as buying all the parts for both axles new from Mazda is about $2000 US, and that is with the racer's discount.

The only really alternative is the complete set from the Driveline Shop which is still $2000, but a lot more axle and CV joint for the $$$.

I have 3 more axles, I will just try one. Can't really tell which was the mate to the one that broke.

DaleClark

iTrader: (55)

Typically the halfshafts seem to last forever and they're quite reliable. Probably why you didn't get a lot of feedback on the topic .

It's also possible that axle got banged around in shipping or something.

I'd get another used one and be done with it. I'm sure they're not too pricey used as they so rarely go out, and it takes maybe a half hour to change one out with air tools. I wouldn't sweat it to hard, just get a good one in there and go.

Dale

jkstill

iTrader: (11)

Thanks Dale, it has been replaced.

Just need to get it back on the ground after a few more items, and off to an autocross.