Mazdeuce does One Lap

The Porsche or your car?

I like that they are scoring all 3 laps. When I ran in '03 they just took the fastest one.

The axles well and truly fell out of the 911. On my car the axle is slowly working it's way out of the diff like it did before. I found a disassembly procedure and it looks like the axles are just retained with compression between the diff and the hub. Curious as to why the dealer mentioned a C clip, because there isn't one. I'm wondering if there isn't some sort of thrust load going on inside the diff. Doesn't really matter at this point. Tomorrow morning we'll try to bash it all back together.

Aren't you glad you brought the hammer now?

That yellow corvette was on a trailer and passed my work truck on the road last thursday. I44 in missouri. my driver said "hey, here comes a race car". when I saw the one lap sticker I showed him this thread. It's all about edjumacatin people one at a time. maybe I49. anyway...

Dusterbd13 wrote: Aren't you glad you brought the hammer now?

We're about six hours from seeing if the dead blow was the right call. I think we've got a pretty solid plan for repair and I have access to a lift if I can make it through the next two days and back to Texas. I'm betting this is going to be a recurring issue and I'm about to be good at putting it back together.

Good luck with the repair!

I wish I had useful knowledge to impart about GM axles and their care and feeling.

In the category of completely different, in a Miata they aren't held in by anything but the suspension components, perhaps the track loads are shifting your suspension around enough that the axles look a bit different that before...... How "out" are we talking?

If you give us a few more details about your axle troubles, maybe we can do some research for you while you're getting some rest between venues.

I am a bit unclear when you say "The axle is falling out". If this were a solid axle, that would make sense, but with an independent I cant relate to what you describe.

The axle setup is like on a FWD car. Bolted to the hub, and slides in the diff. The pressure from the hub/axle holds it in. If the axle somehow under some weird load slid out of the diff the pressure of the system should slide it back in. Something in my diff is causing some sort of thrust load and is pushing the stub out of the diff, and instead of sliding back in, it's just staying out that 1/8 then 1/4 etc. This morning I jacked up the car, pulled the wheel, and could snake the jack handle through the suspension to drive the stub back into the diff. It actually went welll. 20 minutes tops.
If any of you can find an answer it would be hugely appreciated, in the mean time, it's back together and we're on our way to HPR.

This is an area I basically know nothing about so I will just say good luck and that I really enjoy reading this thread. Seems odd that a 911 and V series (two high performance vehicles) are both having axle troubles though.

If it keeps sliding out, it seems like the "snap ring" on the end of the shaft going into the diff is either bad or not there. So my only advice is to check that out if you havent already.

Maybe the bushings that secure the differential housing to the subframe are too soft and allowing it to flex too much. The axles become too short for the gap between the differential and the hub.

Is it an issue in use or is it an annoyance? If there are no grinding noises or issues with the outer hub bearing and nothing is leaking from the diff, then I say leave it. If you feel that it's putting too much pressure on the outer hub and may damage the bearing then obviously fix it.

Is this something that happens at the track only, or on transits too?

If it's just track maybe you need a routine whereas driver A comes in off the track driver B immediately jacks it up and pulls the wheel and starts thwacking it back into the diff while driver A is coming down off the adrenaline high and getting de-suited. If it's 20 mins or less you can probably have it done before Driver A is down from the high, de-suited and had a pee and drink of water.

P.S. Remember you are living out collective dream here. Nothing should go 100% smoothly.

Keep it up and have a blast.

Like the rest of us here, I love that you're doing this with your wagon! Sooo cool!

I'm going to reach out to a friend of mine at the GM Tech Center and see what advice he can offer. He's deeply involved with the V series cars.

Todd

Yeah, I'm with Woody on the bushing give. Did you stiffen up the suspension as well as add sticky rubber? If you are on stock springs with the sticky rubber you are dealing with bigger lean angles than the factory tested setup and greater suspension bushing deformation so overextending the inner joint might happen. It seems like it should stop coming out more at some point though.

An off the wall thought: could the diff be heating up, not venting correctly, and blowing the stubs out?

Adrian_Thompson wrote: Is it an issue in use or is it an annoyance? If there are no grinding noises or issues with the outer hub bearing and nothing is leaking from the diff, then I say leave it. If you feel that it's putting too much pressure on the outer hub and may damage the bearing then obviously fix it. Is this something that happens at the track only, or on transits too? If it's just track maybe you need a routine whereas driver A comes in off the track driver B immediately jacks it up and pulls the wheel and starts thwacking it back into the diff while driver A is coming down off the adrenaline high and getting de-suited. If it's 20 mins or less you can probably have it done before Driver A is down from the high, de-suited and had a pee and drink of water. P.S. Remember you are living out collective dream here. Nothing should go 100% smoothly. Keep it up and have a blast.

If it walks out too far, you can end up ripping the splines out because of a lack of engagement. BTDT.

The previous generation CTS-V used a snap ring on the end of the halfshaft. I suspect yours is the same. If this is broken or missing, I can see you having constant problems.

Adrian_Thompson wrote: Is it an issue in use or is it an annoyance? If there are no grinding noises or issues with the outer hub bearing and nothing is leaking from the diff, then I say leave it. If you feel that it's putting too much pressure on the outer hub and may damage the bearing then obviously fix it. Is this something that happens at the track only, or on transits too? If it's just track maybe you need a routine whereas driver A comes in off the track driver B immediately jacks it up and pulls the wheel and starts thwacking it back into the diff while driver A is coming down off the adrenaline high and getting de-suited. If it's 20 mins or less you can probably have it done before Driver A is down from the high, de-suited and had a pee and drink of water. P.S. Remember you are living out collective dream here. Nothing should go 100% smoothly. Keep it up and have a blast.

This is pretty much the whole situation. Annoyance, not breaking, but it does leak progressively as the axle comes farther out. Right now it looks very manageable, and some stiffer bushings may be the answer in the future. We're here, the car is together and we're ready to go.

Looks like HPR! Enjoy the track. You can take a lot of speed around 1 and 3, I don't think most people take full advantage of them. Don't drop a wheel off the outside of 3, it's a big hole.

Three is actually pretty level with the track right now. I stepped in it to check. Bottomless goo. I'll be staying away. The track looks fantastic but it would take me way more than just the sighting lap to learn it. Suited up and ready to go.

+2 on bushing give. When you're cornering at speed, the outside is compressed and inside rear is drooping, so the axle/CV's will be near full extension. With the grippier tires, the tires are over-coming the control arm bushings and pulling the axle out of the diff.

If the axle is like the one in Keith's post and the force is enough to overcome that snap-ring, could the "friction" the snap-ring is exerting on the splined portion of the diff be what's keeping it from popping back in to place?

If there's enough play in the axle with it up in the air that you can get it all the way out, I'd be curious to see what sort of shape the snap-ring is in (visible wear/damage).

Just ran the first session. 35th in the session, still 37 overall. The axle stayed where it should. Very happy with the morning.

There is a good race shop at Hallett with experienced people. They maintain some high-end race cars there.

More on HPR (probably too late) - the big uphill sweeper (7?) is fast fast fast. I can pretty much go WOT up that with the V8 Miata, most people chicken out but the track goes right where you need it. Just nail the inside curb at the apex and let the car drift out.

Dinner at the TireRack warehouse in Denver. The wonderful smell of a building full of tires.
My co-driver ran the second session slightly faster than me but was holding back because a wheel weight was hitting the front caliper. We swapped wheels from front to rear and didn't check clearances. Oops. Worked out fine though he certainly could have picked up time if there wasn't a constant ticking he couldn't identify.