Everything you wanted to know about the G8 diff and half shafts

[GFORCE1320]

Ok guys, I've tore down the new G8 rear assembly I got and I must say. GM did a much better job on the G8 then they did on the GTO.
First off the half shaft dia is about the same as the GTO but the inner stub axle is much larger as can be seen compared to the GTO inner stub.

They also used a speed sensor in the hub instead of a reluctor ring on the inner stub (big improvement)

The inner axle stubs are the same length on both sides, everything is the same from side to side except the axle shaft (bar) length.
One axle shaft is about an inch longer on one side.

The outer cv joint retains the axle by a snap ring (a hard pull will pop it right out)
The inner cv joint has a large snap ring retaining the cv assembly into it's housing and then another snap ring keeping it on the axle. (remove the large snap ring, pull the cv assembly apart and then remove the axle snap ring to get the axle out)

The axles are 37 spline with a 1.18 dia at the splines.

I'll add more information here when I get the diff tore down to see what makes it tick.

http://i25.photobucket.com/albums/c91/nicholscl/G8/DSC02021.jpg

http://i25.photobucket.com/albums/c91/nicholscl/G8/DSC02019.jpg

Here is why you have the problem with the inner stubs popping out.
You can see the very small machined landing that the retaining ring has to catch on.

http://i25.photobucket.com/albums/c91/nicholscl/G8/G8spidergearlanding.jpg

The retaiining ring area can be seen in this photo on the end of the stub.

http://i25.photobucket.com/albums/c91/nicholscl/G8/G8stubend.jpg

The Camaro center section is a direct bolt in for the G8.
It bolts up perfect, same width and also uses the same inner stubs.
So all you would have to do is find a Camaro center section and bolt it in.

http://i25.photobucket.com/albums/c91/nicholscl/Camaro%20-%20G8/photo-25.jpg

[GFORCE1320]

The axle shafts are pretty much the same diameter as the GTO but the G8 axle shafts are 37 spline, a big improvement.
And the pinion gear is huge. It's considerably larger than the 9 inch ford pinion gear, looks pretty strong.

[99-LS1-SS]

Very good info! I'm sure a lot of guys will be happy to hear that. Do you think it will hold up to ~500 rwhp ok?

[GFORCE1320]

I'll know more when I get the posi tore down. I had to stop for the day.

[Cobra]

Tease! Get back to work :)

[GeorgeInNePa]

I will say this, there don't seem to be many Aussies breaking these.

They've had 6Ms since the beginning, too. ;)

[GM_Fan]

Tease! Get back to work :)

+1 more info..

Thanks for sharing what you have so far.

[wreckwriter]

I will say this, there don't seem to be many Aussies breaking these.

They've had 6Ms since the beginning, too. ;)

Agreed. My biggest priority is the easiest and cheapest way to get 3.27s.

[GeorgeInNePa]

Agreed. My biggest priority is the easiest and cheapest way to get 3.27s.

I've been thinking about this again.

I think our best bet (cheapest) is to wait for 3.27s to be available through GM parts. With the arrival of the GXP, there are going to be gears in the parts system, it's just a matter of time.

[wreckwriter]

I've been thinking about this again.

I think our best bet (cheapest) is to wait for 3.27s to be available through GM parts. With the arrival of the GXP, there are going to be gears in the parts system, it's just a matter of time.

Maybe so. I'm gonna see what the blower does for me, if that's not enough I'll be poking hard at this again.

[GeorgeInNePa]

Maybe so. I'm gonna see what the blower does for me, if that's not enough I'll be poking hard at this again.


lol

Is that a euphemism for something?

;) lol

[wreckwriter]

lol

Is that a euphemism for something?

;) lol

Wasn't meant to be but kinda comes off that way :)

[GFORCE1320]

These rears appear to be as strong if not stronger than the GTO rears so I think they will do pretty good.
The only weak area I see are the axles. They are not any larger in diameter than the GTO axles.
I'll probably offer a 300m axle and some heavy duty driveshafts in the near future.

[GeorgeInNePa]

These rears appear to be as strong if not stronger than the GTO rears so I think they will do pretty good.
The only weak area I see are the axles. They are not any larger in diameter than the GTO axles.
I'll probably offer a 300m axle and some heavy duty driveshafts in the near future.

How about an option to use new shafts with the stock ends for cost savings? Would something like that be feasible? Would that make difference or are the stock parts too weak?

[GFORCE1320]

How about an option to use new shafts with the stock ends for cost savings? Would something like that be feasible? Would that make difference or are the stock parts too weak?

That's exactly what I was thinking of doing. I can build a set with 300m axles and start swapping them out.

[GeorgeInNePa]

I haven't re-installed my stock axles yet.

;)

[GFORCE1320]

I haven't re-installed my stock axles yet.

;)

Let me see how quick I can get some 300m axles ran through the machine shop. You might have to be my first customer. :)

[GFORCE1320]

I've been talking to Harrop about getting some gears for the G8, I'll keep you all posted on what I can dig up.

[GFORCE1320]

I am in talks with a rep at ZF and they are going to look into different gears for me.

[jbradsh1]

Ok guys, I've tore down the new G8 rear assembly I got and I must say. GM did a much better job on the G8 then they did on the GTO.
First off the half shaft dia is about the same as the GTO but the inner stub axle is much larger as can be seen compared to the GTO inner stub.
They also used a speed sensor in the hub instead of a reluctor ring on the inner stub (big improvement)

I'll add more information here when I get the diff tore down to see what makes it tick.

http://i25.photobucket.com/albums/c91/nicholscl/G8/DSC02021.jpg

http://i25.photobucket.com/albums/c91/nicholscl/G8/DSC02019.jpg

Thanks for this information. I think you just put a lot minds at ease.

[GFORCE1320]

In about 3 weeks I'll have 300m axles that you can swap out with the stock axles.
I dont see any reason to change the inner and outer stubs, just the axle shaft.

[-Ray-]

Any update on gear sets?

[GFORCE1320]

Any update on gear sets?

No, I have a guy at ZF looking into different gears. I'll pester him some more to keep him looking.
I would imagine when the Camaro comes out it will have the same diff and will also open up more gear options.

[-Ray-]

Yep, I'm looking to do the 3:27 gear change in mine.

[GFORCE1320]

I added some more information to first post.

[GRRRR8]

BUMP!!!! Chris we are breaking axles and its been almost a year. :hang:

[SpeedRacerX]

From Chris' 1/4/09 post: "The only weak area I see are the axles."

Like Nostradamas...

Subscribing.

[Devilish34]

BUMP!!!! Chris we are breaking axles and its been almost a year. :hang:

Inner axle stubs to be specific

[GRRRR8]

Inner axle stubs to be specific

Correct! I dont know if it can break the shaft itself, but we know it can break the stub for sure.

[SpeedRacerX]

Since this seems to be a good thread for this timely question, here goes...

I'm a 13-flat kinda G8 right now. With no additional power adders, when I install my 3.70 diff, will I start breaking these axles?

Or, does it take a LOT more power to do that or maybe we just don't know the root cause yet?

Swapping diffs is now making me nervous.

[Devilish34]

Since this seems to be a good thread for this timely question, here goes...

I'm a 13-flat kinda G8 right now. With no additional power adders, when I install my 3.70 diff, will I start breaking these axles?

Or, does it take a LOT more power to do that or maybe we just don't know the root cause yet?

Swapping diffs is now making me nervous.

Don't know the answer bc ...I don't know why or how they are breaking.
The problem may not be the axles.

Maybe only the Black G8s make enough power to break axles

[GeorgeInNePa]

Don't know the answer bc ...I don't know why or how they are breaking.
The problem may not be the axles.

Maybe only the Black G8s make enough power to break axles

You are on the path to the truth, Padawan...






lol

[Devilish34]

You are on the path to the truth, Padawan...






lol

Might have to paint mine red to slow it down

[GeorgeInNePa]

Just get the red/black interior and slow it down a little.

;)

[Devilish34]

Just get the red/black interior and slow it down a little.

;)

I thought the red catch can would reel it in some but I guess I was wrong

[GFORCE1320]

Sorry guys,

Something has popped up since I opened my mouth about the axles almost being done.

I have been diagnosed with Luekemia and I'm in the hospital.
I wont be getting out for another 3 weeks :(
I'm expected to make a good recovery (thank god)

The G8 axle design is done and ready for production but I wont be starting the production run until I get out of here.
It's just too much for my limited staff to handle with out the boss there, LOL

I'll keep you all posted when I get out of here.

Thanks
Chris

[GeorgeInNePa]

Sorry guys,

Something has popped up since I opened my mouth about the axles almost being done.

I have been diagnosed with Luekemia and I'm in the hospital.
I wont be getting out for another 3 weeks :(
I'm expected to make a good recovery (thank god)

The G8 axle design is done and ready for production but I wont be starting the production run until I get out of here.
It's just too much for my limited staff to handle with out the boss there, LOL

I'll keep you all posted when I get out of here.

Thanks
Chris

WOW!

Get well soon!

[irnwkrkev]

Our prayers are with you in this tough time. Wish you a speedy recovery!

[polo]

Wow is right! When someone's away from a forum for a while you think it's because they're busy or something along those lines. You never it's because they're battling cancer.

I hope you're right about making a full recovery. Best of luck to you.

[MGM GT]

Our thoughts are with you! Hope you have a fast recovery!

[GFORCE1320]

Your gonna like the axle kits I have planned, I just have to get out of here first :)

Thanks
Chris

[G8GT721]

WOW!

Get well soon!

+1

[GRRRR8]

Get well soon Chris!

I am getting close to 500RWHP N/A and have a feeling I will need your HELP!!

[edmanet]

I wish you a speedy and full recovery. I know just exactly how you feel. I was diagnosed with cancer about 3 months ago and I had no clue. And like you I'm expected to make a full recovery.

If you need anything just pm me and if I can arrange it....I'll have it sent to you.




Sorry guys,

Something has popped up since I opened my mouth about the axles almost being done.

I have been diagnosed with Luekemia and I'm in the hospital.
I wont be getting out for another 3 weeks :(
I'm expected to make a good recovery (thank god)

The G8 axle design is done and ready for production but I wont be starting the production run until I get out of here.
It's just too much for my limited staff to handle with out the boss there, LOL

I'll keep you all posted when I get out of here.

Thanks
Chris

[Devilish34]

Sorry guys,

Something has popped up since I opened my mouth about the axles almost being done.

I have been diagnosed with Luekemia and I'm in the hospital.
I wont be getting out for another 3 weeks :(
I'm expected to make a good recovery (thank god)

The G8 axle design is done and ready for production but I wont be starting the production run until I get out of here.
It's just too much for my limited staff to handle with out the boss there, LOL

I'll keep you all posted when I get out of here.

Thanks
Chris

Sorry to hear about this Chris I will keep you in my prayers.

Get Well Soon

[edmanet]

Get well soon Chris!

I am getting close to 500RWHP N/A and have a feeling I will need your HELP!!

You think the axles will only solve half the issue ??

[GRRRR8]

The axles will help with the breakage and the posi issue will fix the rest.

[GFORCE1320]

Here is why you have the problem with the inner stubs popping out.
You can see the very small machined landing that the retaining ring has to catch on.

Our new stubs will have the retaining ring on the very end of the stub so it snaps out past the spider gears.

http://i25.photobucket.com/albums/c91/nicholscl/G8/G8spidergearlanding.jpg

The retaiining ring area can be seen in this photo on the end of the stub.

http://i25.photobucket.com/albums/c91/nicholscl/G8/G8stubend.jpg

[GFORCE1320]

The Camaro center section is a direct bolt in for the G8.
It bolts up perfect, same width and also uses the same inner stubs.
So all you would have to do is find a Camaro center section and bolt it in.

The diff in the pic is out of a 2010 Camaro SS, the cradle is from a G8.

http://i25.photobucket.com/albums/c91/nicholscl/Camaro%20-%20G8/photo-25.jpg

[SpeedRacerX]

The Camaro center section is a direct bolt in for the G8.
It bolts up perfect, same width and also uses the same inner stubs.
So all you would have to do is find a Camaro center section and bolt it in.

The diff in the pic is out of a 2010 Camaro SS, the cradle is from a G8.

http://i25.photobucket.com/albums/c91/nicholscl/Camaro%20-%20G8/photo-25.jpg

Cool. Now what is the benefit? Stronger, lighter, axles don't pop out, more standard ring & pinion options inside, easier to find spare parts?????

[GFORCE1320]

The Camaro diff is larger, stronger and will be more available since they will make a gazillion of them.

[Muff Daddy]

what gears come in the camaro unit stock?

[SpeedRacerX]

The Camaro diff is larger, stronger and will be more available since they will make a gazillion of them.

Got it. And there will be state-side, aftermarket, more reasonably priced, ring & pinion options I would think too...

[vic2186]

So it will be as easy as finding a camaro diff with 3.27in it and swapping it out an not having to worry bout peg leg burnouts and axle breaks??

[wnt2gofst]

SO i get the camaro diff need anything else to make this work. new axles, drive shaft.

[GFORCE1320]

I'll measure the Camaro housing to see if the G8 driveshaft will work.

[vic2186]

kool

[wnt2gofst]

I'll measure the Camaro housing to see if the G8 driveshaft will work.

I answered this in other thread..lol...but good to know again.

[gr8lover]

Does the camaro diff retain the axles the same way as in the G8... sounds like it? does this mean they will have same issues as on G8's.... pulling out? I would think if someone gets the camaro diff, they would at least want to get the better setup to avoid the axles pulling out... new setup that we bought with the better snap ring, etc...???

[GFORCE1320]

Does the camaro diff retain the axles the same way as in the G8... sounds like it? does this mean they will have same issues as on G8's.... pulling out? I would think if someone gets the camaro diff, they would at least want to get the better setup to avoid the axles pulling out... new setup that we bought with the better snap ring, etc...???

Yes, the Camaro diff has the same problem. But both the G8 and Camaro use the same inner stubs so our stub design will fix the problem.

[GFORCE1320]

The G8 driveshaft will also work. Both center sections are the same length and the pinion yokes have the same bolt pattern.

Thanks
Chris

[Muff Daddy]

The G8 driveshaft will also work. Both center sections are the same length and the pinion yokes have the same bolt pattern.

Thanks
Chris

You sir are my hero! Now I just need to keep an eye on ebay...

[r33pwrd]

You sir are my hero! Now I just need to keep an eye on ebay...

good luck! I bet they will be hard to find as the High HP camaro guys will snatch them up asap!

[r33pwrd]

will camaro internals work? I would think there will be aftermarket gers for them (of not allready)

[Mike P]

will camaro internals work? I would think there will be aftermarket gers for them (of not allready)


Question:

So if I was starting from a stock G8 GT drivetrain, and I wanted to upgrade to either 3.27 gears or 3.45 gears, what parts would all would be needed to properly do an upgrade so I wouldn't have to worry about breaking axles or doing 1 wheel burnouts?

http://shop.gforce1320.com/category.sc?categoryId=19

I'm assuming:

-G8 / GXP ANTI-WHEEL HOP AXLE KIT DRIVER AND PASSENGER SIDE


Would you also need:

-G8 / GXP HARROP Detroit Truetrac posi
-G8 33 SPLINE SPOOL




I'm definitely a noob when it comes to 'Drivetrain', just trying to learn & know what I need....


...

[GeorgeInNePa]

TrueTrac or spool, not both.

[Mike P]

TrueTrac or spool, not both.


Thanks!

I'm definitely thinking I need to have a phone conversation with you before my next Drivetrain mods....


...

[jeff]

Thanks for the goods.I am about nuts with a diff. swap.My dealer swapped mine and I started leaking oil.I got leaking axle seals.They seem to think there is a tool made for correct install of the seals.Thing is nobody has or makes the tool it looks like.New axle seals are in the parts dept. and I am waiting for someone to figure it out what to do.Did you run into this problem ??What are they doing wrong??Thanks for any feedback you can give me...

[wreckwriter]

They must have just jammed the axle(s) in without making sure it was lined up. That's about the only way to booger up those seals.

[jeff]

Is there a tool for the install ?

[wreckwriter]

Is there a tool for the install ?

Haven't been able to find any info on changing the seal. Most likely yes there is a tool.

[GeorgeInNePa]

Thanks for the goods.I am about nuts with a diff. swap.My dealer swapped mine and I started leaking oil.I got leaking axle seals.They seem to think there is a tool made for correct install of the seals.Thing is nobody has or makes the tool it looks like.New axle seals are in the parts dept. and I am waiting for someone to figure it out what to do.Did you run into this problem ??What are they doing wrong??Thanks for any feedback you can give me...

If a Service Dept has no one that knows how to install an axle properly, I'd be worried.

If a Service Dept has no one that knows how to install an oil seal without fucking it up, I'd take the seals and run, not walk to the exit.

[GeorgeInNePa]

Haven't been able to find any info on changing the seal. Most likely yes there is a tool.

Pop the old one out with a seal remover or pry bar/large screwdriver.

Fill the back side of the new seal with bearing grease, to hold the "spring" in place while installing the seal.

Place seal in housing and using a circular pattern, tap into place with a hammer.

Unless these are super duper special seals, that will work.

[jeff]

Thanks! Will find out Monday...

[Showoff G8]

Hey do you know what size the axle nut is on the half shafts by the rotor?

[AVIDMOTION]

So, it is still true all I would need is the center pumpkin from a Camaro no real other parts needed? What gear oil do I refill with, and do I need to add the limited slip diff additive?(Lucas syn says none needed with their HP lube.And what gears do we have to chose from as of now. Lastly what is the part number for the 3.27 or 3.45 GM gears?
Thanks