Well, look at that...(axle&diff)

[GeorgeInNePa]

Isn't there supposed to be a snap ring on there and a bit more splines?

http://img.photobucket.com/albums/v320/GeorgeInNePa/G8/axle.jpg

Oh, there it is!

http://img.photobucket.com/albums/v320/GeorgeInNePa/G8/diff.jpg

:wacko:

[Devilish34]

Like I said on the phone that looks very familiar

[99-LS1-SS]

I was going to say a smart ass remark but, given my Easter Bunny type traction, I should probably keep my mouth shut.

[MGM GT]

Damn history repeats itself! At least you got a new one on the way.

[Devilish34]

Damn history repeats itself! At least you got a new one on the way.

I bet the diff looks ok when he pops it open. Well at least mine did

[Devilish34]

I was going to say a smart ass remark but, given my Easter Bunny type traction, I should probably keep my mouth shut.

Yes please leave the smart ass comment to the professionals

[MGM GT]

I bet the diff looks ok when he pops it open. Well at least mine did

So who is gonna be the first to spool it like the Camaro guys did?

[Devilish34]

So who is gonna be the first to spool it like the Camaro guys did?

Parts seem to be a problem

[GeorgeInNePa]

I just can not figure what is breaking the end of the axle off.

It broke at the cir-clip grove. It left the clip inside the splined area of the side gear. That tells me that it didn't break off until the end of the axle was in the splined area. If pulling the axle into the side gear (ie, removing the axle from the diff) will break the end off, it would break off every time you removed the axles from the car.

Someone explain this to as if I rode the short bus...

[Devilish34]

I just can not figure what is breaking the end of the axle off.

It broke at the cir-clip grove. It left the clip inside the splined area of the side gear. That tells me that it didn't break off until the end of the axle was in the splined area. If pulling the axle into the side gear (ie, removing the axle from the diff) it would break off every time you removed the axles from the car.

Someone explain this to as if I rode the short bus...

I can't and neither could Dan (guy who fixed my car) or Kyle (BMR) or anyone else I spoke to.

[SpeedRacerX]

Do we have access to any GM drivetrain engineers on either of the forums?

[MGM GT]

Parts seem to be a problem

haha I thought they lincoln locked it....

[Devilish34]

haha I thought they lincoln locked it....

I'll pass on the LL lol RPM trans is building diffs for the Camaro but not the G8 :(

I might have to call them again today

[Remikinz]

wow totally clean break O.O

[Frans96ss]

I'll pass on the LL lol RPM trans is building diffs for the Camaro but not the G8 :(

I might have to call them again today

Tell TJ i told you to call and bug him :)

[Devilish34]

Tell TJ i told you to call and bug him :)

Will do probably be later today or tomorrow

[NYG8GT]

I just can not figure what is breaking the end of the axle off.

It's a GM part. Need I say more?

[SpeedRacerX]

I wonder what material they are made from, were they heat treated or hardened??? If not, maybe that's an easy remedy...

[GRRRR8]

The axle coming out is why it is breaking. The part that is breaking doesnt even ride on the splines. We need to figure out how it is ejecting it. Lots of ideas, no hard proof......yet.

[SpeedRacerX]

Who is most responsible for the design and function of this? GM, Holden, ZF, all the above????

I'm asking because I'm willing to spend some time to find out who knows this rear the best and see if they can shed any light on this...

Sometimes the answer is the aftermarket; sometimes the manufacturer; sometimes the "tinkerer" like me, and sometimes guys like Charlie.

Just willing to help for everyone's benefit.

[SpeedRacerX]

What about the 1000 HP Extreme Duty Axles and CV Joints from Spohn?

From their website:

"The factory G8 axles are made with different diameter axle bars, but the spline diameter is the same on both sides and the large diameter axle bar tapers down to a spline that is half the diameter. This transition creates a weak point on the axle bar that cannot withstand increased horsepower."

[Remikinz]

http://forums.hybridz.org/showthread.php?t=116207

might explain a bit... seems to be a similar problem

[SpeedRacerX]

Is it possible that the one tire spinning issue is the first sign of a pending stub axle failure?

[GeorgeInNePa]

Is it possible that the one tire spinning issue is the first sign of a pending stub axle failure?

It's a sign that the LSD is failing. Something related to that is ejecting the stub from the diff.

[GeorgeInNePa]

http://forums.hybridz.org/showthread.php?t=116207

might explain a bit... seems to be a similar problem

Thanks, but that seems to be unrelated. The LSDs (John's and mine) are still together, the spiders are in there tight.

[Devilish34]

Thanks, but that seems to be unrelated. The LSDs (John's and mine) are still together, the spiders are in there tight.

Even the pc that sheared off the end is differnt. Look at the tear marks yuck

[Remikinz]

Thanks, but that seems to be unrelated. The LSDs (John's and mine) are still together, the spiders are in there tight.

very true... hmm Im thinking showing my bf these pics perhaps he can lend some knowledge on this

[GFORCE1320]

I just finished design work today on our G8 stub to stub 1000hp axle set up.

It'll consist of our patent pending bolt together 300m inner stubs,
300m axles (big axle on passenger side, normal on drivers)
One piece outer stubs

I expect to have the first set in a car in 4-5 weeks for some testing.

The retaining rings on the G8 are pretty wimpy, I'll see if we can use the hardened retaining rings we use on our GTO stubs to hold them in better.

I'll have pricing here real soon, I have to get a couple prices from the machine shop tomorrow.

Thanks
Chris

[Frans96ss]

I just finished design work today on our G8 stub to stub 1000hp axle set up.

It'll consist of our patent pending bolt together 300m inner stubs,
300m axles (big axle on passenger side, normal on drivers)
One piece outer stubs

I expect to have the first set in a car in 4-5 weeks for some testing.

The retaining rings on the G8 are pretty wimpy, I'll see if we can use the hardened retaining rings we use on our GTO stubs to hold them in better.

I'll have pricing here real soon, I have to get a couple prices from the machine shop tomorrow.

Thanks
Chris


Let me know on some pricing. Im sure i could sell a few sets.

[99-LS1-SS]

Is there a chance that the reason for the one wheeled burnout is because the tip of the axle has already broken and hasn't wormed it's way out completely?

[Devilish34]

Is there a chance that the reason for the one wheeled burnout is because the tip of the axle has already broken and hasn't wormed it's way out completely?

I doubt it but who knows for sure. I would think a pc of axle the size of a quarter would either A) tear up something else or B) show some wear on it from swimming around

The boom when it breaks also stinks of it failing at the time the axle walks(or what ever it's doing). As George said it's like the car got hit with a sledge hammer(and I mean a BFSH!!) I also am wondering what the CV joints look like.

[GeorgeInNePa]

Is there a chance that the reason for the one wheeled burnout is because the tip of the axle has already broken and hasn't wormed it's way out completely?

If the axle is out and the drive-shaft is turning, you hear grinding noises from the rear of the car.

I could hear it clearly over the engine at, and just above, idle rpm while in D.

Also, the car won't move, all torque goes to that side of the diff.

[99-LS1-SS]

What I'm thinking in my head that I'm having trouble putting into words is:

Maybe the suspension is flexing or moving just enough under heavy acceleration to allow the sheared axle to "pop out" in turn causing the boom sound. If it's hanging in there by 1/2 inch or less it could still be enough to move the car. Not sure if any of this makes sense but it's just a different angle.

[grandmacpubah]

so are there two problems here or one? Is the problem the axles or the LSD, or both?

[SpeedRacerX]

What I'm thinking in my head that I'm having trouble putting into words is:

Maybe the suspension is flexing or moving just enough under heavy acceleration to allow the sheared axle to "pop out" in turn causing the boom sound. If it's hanging in there by 1/2 inch or less it could still be enough to move the car. Not sure if any of this makes sense but it's just a different angle.

It does make sense. That's what I was getting at when I said maybe the one wheel turning was in fact an indication of a problem within the diff and it could be ready to go at any minute, under the right amount of torque and drivetrain flex or angle. Also, in Remikinz post - although way different - the actions and indications of LSD internal problems, while still being able to move the car up to the point of breakage, and then a final breakage where similar to what we are seeing. I'm not sure if it matters that one tore unclean while the other sheared clean off, does it?

[edmanet]

so are there two problems here or one? Is the problem the axles or the LSD, or both?

I would say both.

[norm8332]

I'm not an expert either but, wouldn't the fact that most if not all of the power is going through one wheel etc instead of two cause the fracture?

I think the fracture is a result of a previous LDS failure. If the load was properly distributed I don't think it would have broken.

[GeorgeInNePa]

I'm not an expert either but, wouldn't the fact that most if not all of the power is going through one wheel etc instead of two cause the fracture?

I think the fracture is a result of a previous LDS failure. If the load was properly distributed I don't think it would have broken.

This is what I think is closest to what is happening.

I just don't know what is popping the axles out. I do believe the axle moves out first, then the end gets broken off. Since the c-clip is in the splines and not down inside the diff, that leads me to believe the axle doesn't break first (in all honesty it can't break first, there's no load on that piece).

[jakesg8]

George ? Do you and devilish have the same struts? What if the stub was pulling out just enough to allow the stub to un seat from the diff bearing and let the c-clip get in side of the spider gear and snap the end off.That would let the spline wiggle around a bit under power.And being that the c-clip groove is the weakest part.???

[GRRRR8]

Suspension does not seem to have anything to do with it.

[GeorgeInNePa]

George ? Do you and devilish have the same struts? What if the stub was pulling out just enough to allow the stub to un seat from the diff bearing and let the c-clip get in side of the spider gear and snap the end off.That would let the spline wiggle around a bit under power.And being that the c-clip groove is the weakest part.???

Nope, he's got the stock stuff, front and rear. Mine are the Pedders Xa's at lower than stock height.

His broke the Driver's side axle. Mine broke the Passenger side axle.

He uses drag radials, I use DOT stamped bias ply tires.

[GRRRR8]

The issue is the clutch packs. Working on the fix using my 3.70 as the test mule. Just waiting for a call back. It sucks trying to get anything done during the holidays. :hang:

[Devilish34]

Nope, he's got the stock stuff, front and rear. Mine are the Pedders Xa's at lower than stock height.

His broke the Driver's side axle. Mine broke the Passenger side axle.

He uses drag radials, I use DOT stamped bias ply tires.

Different burnout and launch routines too. Also George broke on a hard launch and I broke walking it out to what would of been a 2.1+ 60'

[grandmacpubah]

The issue is the clutch packs. Working on the fix using my 3.70 as the test mule. Just waiting for a call back. It sucks trying to get anything done during the holidays. :hang:

that's cool you're getting to bottom of it charlie. I hate it when I don't know what you're talking about though LOL

[GRRRR8]

I hate it when I don't know what you're talking about though LOL

Thats most of the time! :nah:

[SpeedRacerX]

The issue is the clutch packs. Working on the fix using my 3.70 as the test mule. Just waiting for a call back. It sucks trying to get anything done during the holidays. :hang:

Charlie, can you test clutch packs with a Dyno? :rofl:

[GRRRR8]

Charlie, can you test clutch packs with a Dyno? :rofl:

I will let you know when the dyno reads 500. :)

[Fatdaddy]

I will let you know when the dyno reads 500. :)

Anyone who has gone through a progressive build up of a heavy, high hp car knows how this process works:

1. You make enough power that you can't launch hard enough.
2. Install stickier tires.
3. Break axles due to the sticky tires.
4. Install bullet proof axles.
5. Differential breaks.
6. Install spool.
7. U-joints break.
8. Install bullet proof driveshaft and U-joints.
9. Now that car hooks without breaking, make more power.
10. See step 1.
11. Repeat step 2
12. Diff housing breaks.
13. Install bullet proof housing.
14. Repeat step 9.
15. Repeat step 1.
16. Rebuild rear suspension subframe.
17. Repeat step 9 etc., etc., etc.

The costly part of this process is doing it with a new platform and parts.

[GeorgeInNePa]

Anyone who has gone through a progressive build up of a heavy, high hp car knows how this process works:

1. You make enough power that you can't launch hard enough.
2. Install stickier tires.
3. Break axles due to the sticky tires.
4. Install bullet proof axles.
5. Differential breaks.
6. Install spool.
7. U-joints break.
8. Install bullet proof driveshaft and U-joints.
9. Now that car hooks without breaking, make more power.
10. See step 1.
11. Repeat step 2
12. Diff housing breaks.
13. Install bullet proof housing.
14. Repeat step 9.
15. Repeat step 1.
16. Rebuild rear suspension subframe.
17. Repeat step 9 etc., etc., etc.

The costly part of this process is doing it with a new platform and parts.

You forgot one thing. You need to add at least one transmission in there somewhere. :(

[Fatdaddy]

You forgot one thing. You need to add at least one transmission in there somewhere. :(

Right you are. Forgot the tranny, flex plates, output shafts and housings for the auto's, clutches, shifters, synchro's and shafts for the stick cars. You obviously know the drill.

[gr8lover]

You guys have probalby been thru this but forgive me if I am way off, but would it fix this issue if we just used alot stronger snap ring?? If the snap ring was the issue and it seems like it was due to the shearing of the end, if the snap ring didnt come off-- would it break??? modify current shaft to accept alot stronger snap ring???

[edmanet]

What about the 1000 HP Extreme Duty Axles and CV Joints from Spohn?

From their website:

"The factory G8 axles are made with different diameter axle bars, but the spline diameter is the same on both sides and the large diameter axle bar tapers down to a spline that is half the diameter. This transition creates a weak point on the axle bar that cannot withstand increased horsepower."

$1800 is a little expensive !!!

[GeorgeInNePa]

$1800 is a little expensive !!!

How much do you have in your new diff?

;)

[Devilish34]

vP_7b-j2Hfs

[G8GT721]

i could't hear it break, but that guy did lol

[GRRRR8]

Damn George! It took longer for the smoke to clear then it did to break the axle! :wacko:

[Devilish34]

Damn George! It took longer for the smoke to clear then it did to break the axle! :wacko:

you should of seen it when he opened the trunk 5+ min after that

[GeorgeInNePa]

See the smoke roll under the car and come out the drivers side? That's why I thought both were spinning...

[GRRRR8]

See the smoke roll under the car and come out the drivers side? That's why I thought both were spinning...

Yeah. After about 3 seconds it looked like a 2 tire burnout, but you can see it clearly before you depleted the ozone and created the cold weather we are having in Texas! LMAO!

[edmanet]

you should of seen it when he opened the trunk 5+ min after that

Yeah it was like he had a bonfire in his trunk.
Don't those rims look nice on that orange car !?!?!?

[GeorgeInNePa]

Yeah. After about 3 seconds it looked like a 2 tire burnout, but you can see it clearly before you depleted the ozone and created the cold weather we are having in Texas! LMAO!

lol

Al Gore hates me.

[G8GT721]

how do we do greener burnouts?

[GeorgeInNePa]

how do we do greener burnouts?

Buy one yellow and one blue.

http://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Ecsta+SPT+Colored+Smoke

;)

[G8GT721]

lmao that was quick

[SpeedRacerX]

Guys,

Not sure if this is good info or not but I thought I'd share. This is from Frank at the Driveshaftshop. They have axles for G8s and are considering doing a one-piece driveshaft.
Here are his comments on the driveshaft and most importantly, the axle breaking issue.

I know several of you are looking into all options; just thought I'd try to help.
------------------------------
Yes we have experimented with the single shaft but i believe there is a harmonic resonance in the car that would make a 2 piece aluminum shaft needed. i have attached a picture of a prototype shaft we made for Lingenfelter. it will be just like it but a little longer to fit the G8 chassis.

My educated guess would be one of the following, something is causing the axle to be dislodged from the snap ring mount. you wrote that they are experiencing one wheel burn outs. this is more than likely because the axle was not in the diff at the time.its possible for the axle to come in and out if the snap ring is not strong enough like i said the only way for the little section to be able to be broken off would be if the entire weight of the car was being driven on that little section (because it wasn't all the way in)

1. the length of the axle may not be correct, being its mostly at the track its possible when the suspension crouches down its doing one of 3 things. either the axle is being pulled from the boot being stretched to far out causing a hydro/pulling spring effect on the inner causing it to pull out i know this might sound a little far fetched but it happens alot with axles. boots being sealed and then pulled have allot more strength that you would imagine. the 2nd thing it would be is the bar being to short and the inner c.v. being bottomed out open causing the snap ring to release. keep in ming the axle is normally even with the ground, when the car squats sown the wheel goes deep into the wheel well
the distance from the diff to the wheel is greatest at this point.

2. it could be as simple as needing the snap ring that hold it in to spread out more to
hold it in better or a stronger one installed.

3. the design of the inner c.v. is a tripod and not a very good design, this would be momentarily locking up not letting the inner cv move in or out properly when under load causing the problem.

checking the length of the axle would be quite easy,lowered cars may be more prone to this problem if it turns out to be the cause. with the car on the ground take the cv axle nut off and push the threaded section into the hub. it should only move in about 1" from start to finish. please check both sides......

if the boot is the cultrate the way to check it would be to ask if when the axles are being installed if the boots seems to be "extended" when installed or if excessive pressure is needed to push the cv into the diff ?
---------------

[GRRRR8]

I want to address Franks points on this to maybe help us all.

1. The length may not be correct but these are factory axles and it is happening on stock height and lowered cars with mostly stock suspension to highly modded suspension.

2. Lets say the axle did disengage. It would still be on the splines so it would still spin the tire or so you would think. We do know once it breaks that little piece off it makes a lot of noise, so I would assume if the axle wasnt engaged it would make a noise when pulling forward to the line after the burnout.

The LSD is the issue because if you back up a few feet and pull forward both tires spin. Why it is ejecting the axle because of this is the mystery.

[GFORCE1320]

I'm addressing the stub retention on our axle design.
The OEM stubs have a square retaining ring that catches on a machined area inside the spider gear. There isnt much surface area at all for the ring to catch on, only about .050 of a lip.
On our stubs, I am moving the retaining ring out to the end of the stub so it will catch on the inside of the spider gear. It will pass through the spider gear and pop out once past it.
This is a much better retention method then what GM used.

Thanks
Chris

[Devilish34]

When I broke mine the run prior I had one tire spin but when I broke both tires engaged during the burn out. Funny part is I slowly walk into burnouts and launch a hell of a lot softer than George.

[jakesg8]

I'm addressing the stub retention on our axle design.
The OEM stubs have a square retaining ring that catches on a machined area inside the spider gear. There isnt much surface area at all for the ring to catch on, only about .050 of a lip.
On our stubs, I am moving the retaining ring out to the end of the stub so it will catch on the inside of the spider gear. It will pass through the spider gear and pop out once past it.
This is a much better retention method then what GM used.

Thanks
Chris

Chris when I pulled that diff for you. I noticed where the axle stub goes into the diff carrier. The opening is flaired do you think that would allow the stub to wiggle around enough to snap the end of the stub shaft off. Then again what the hell do I know LOL

[GFORCE1320]

No, the diff has an area just inside the side bearings that is just a tiny bit larger then the stubs, this keeps the stubs nice and wobble free.
It would be better to have the stub supported on the outer end with a bearing or something but who knows why GM decided on this set up.