about my stock 05 rear.

I've read through a ton of posts in the archives, and come to the conclusion that I need a C5 rear that will need to be modified, and some hardened output shafts.

I plan on making some more power here really soon, and I'd rather be proactive in my quest to keep my car rolling, than to wait for it to break, and have to have it towed.

Which leads me to this. My existing rear end is in perfect condition (9k miles), and I'd like to trade it towards the above mentioned equipment with new gears, etc. Any particular direction I should be looking?

Thanks!

 

I've been well over 530rwhp for 3 years (now well above that) and never had an issue. I recently had hardened output shafts put in only because it was in for power mods. I'm a firm believer in fix it if it breaks.

 

I hear ya, but I'd rather just get it done with & not worry if I want to launch. There's nothing worse than breaking down at launch, it's embarrassing!

 

If you're going to a 1/4 mile track where traction is enhanced, anything can happen. It won't happen on the street with street tires.

 

Even with 345's in the rear?

 

Most of the occurances of rears breaking, be it '05 or above, have been at the track. The surface of the track is very different than that of the street. I have seen rears go on street tires as well as DR/slicks. If you plan on racing I would upgrade the rear. Keep in mind that if the rear goes the damage may not be contained to just the diff. I have seen blown rears take out the entire tranny as well. It's better to be safe than sorry.

 

Statistics wouldnt make me feel comfy with thinking your car is the norm. You are very much the exception.

The core in your car is 2100 bucks and if you paid 1700 for gears and shaft in a 2005 core and it breaks the lesson is very expensive. The lesson may not end there since many diff fractures are often accompanied by a trans output shaft break and thats now a 5000 dollar repair with the diff.

Fix it before it breaks. For street tire cars with lots of wheel spin, the reason you didnt break is because you arent getting much of the power to the ground. Put on r-compound tires with a grabby clutch and see how statistically divergent you are then.

Good luck.....I am not wishing anything bad on you but dont confuse the common thing with an exception to the rule. The 05 diff is a dead end.

 

I recall back in 2005 reading about bone stock cars breaking the diff on the street with stock tires. I was regretting buying the car until Cartek came out with the first fix for the diff with a 2004 diff transplant. There was no 2006 yet when I saw these were breaking.

The breaks were not limited to cars at tracks with high power. Essentially natural selection would have it that all production 2005's with weak cases broke and the stronger ones are the one peopole are in posession of today thinking the diff is fine and something was wrong with the other cars. It was, and is, a bad design and people would be foolish to use a 2005 core and pay 1700 for a re-gear and shaft upgrade. None of that money comes back if it cracks. Also keep in mind that most gear upgrades through vendors are exchange units and you dont get your proven 2005 case back unless you use a tuner that does the work to your diff while the car is on a lift.

If you plan on gears just factor in the case swap. Its money well spent.

 

A street tire is a street tire and a 275 r-compound is way harsher than a 345 street tire on a diff. Going to a 345 from the 285 is a marginal improvement in traction.

 

I got my 2005 in Aug 2004 and I recall reading almost weekly (you became a member a year after those posts)about the breaks that were happening on the street with stock runflats. Those weakest ones failed and eventually only the strongest 05 cases lived.

 

ECS didn't seem too worried about my differential. I added a Spec twin disc clutch and shaft when they turned up the boost and meth. I would think they would have warned me if it was a big deal.

 

I bought my car in Feb 05.

 

So what's the solution?

 

Your car is the exception not the rule. Lots of 05 diffs broke. Your's didnt...great for you ,but it doenst mean it wasnt a problem. It was.

I dont think people should be reading what youre typing and thinking the diff in their car wont break because you got lucky.

 

I understand what you're saying and have seen the physical differences in the rears. If I was going to track the car it would have been replaced, but I don't. I also don't know the actual numbers of failures to success.

 

Again, point being there were lots of posts 6 months prior to you buying your car or becomming a member here stating they broke the diff on the street with stock cars and stock tires. I'm not getting your insistance on the topic here. before you got your car and before you became a forum member lots of 2005 diff broke. Your's didnt so that means 2005 diffs are as strong as any other and because you didnt break with lots of power no one should look at the dozens of diff breaks that broke with no mods? They get negated?

I post to let people know the true statistic isnt good for 2005 diffs. I read about 2 dozen such breaks and your experience means they dont count?

 

OK, no porblem. They posted prior to you becomming a member. I'm not fishing around the archives to find the posts but I think most know I am just trying to keep people from making a mistake with upgrading a 2005 case diff. MOST of those breaks were on the street not the track.

 

Well, what exactly are the statistics? A few dozen out of 40,000? Just curious.

 

There are 2 solutions.

A swap to a newer case (2006-2009) is the first option. This one requires the swap of the back transmisson casing to accept the different bolt pattern of the stroger case.

The second is my preference and whats on my car. I had a 2004 (C5) diff grafted onto the existing transmission whcih then requires the fabrication of a center mount to hold the diff in place. This option allows the diff to rock a bit back and forth as it did on the C5 to absorb some of the shocks of the driveline. I have 700rwhp with this option with sticky tires and even wild wheel hop didnt break the diff which can break any diff.

The biggest advantage to the second option is that the core is 700 bucks whichis 1/3 the cost of a C6 core. If I do blow one up I simply order a new diff and pay the 700 dollar core charge and it will fit on my car as is with the center mount work already done. If a C6 core blows up its a 2100 dollar charge. There are countless low 9 sec C5's out there with the C5 core so I would say its as proven as any platform.

There is no way to tell the diff was a swap in. Even a GM tech looking at it thought the driveline was stock even looking right at the diff. I was asking him if he saw anything unusual abotu the diff and he couldnt pick it out. It looks stock.

Cartek did my fabrication. I hear they do the C6 diff swap only now but I would insist on this if I had to do it again. 700 dollar cores are easier to swallow then a 2100 dollar core.

 

What he said....


I'm looking for direction to change this to the C5 version, and while I'm at it, I might as well change the gearing to new as well. My question again, is where can I trade my core & get the parts that I need.

The 05 diff thing has been done to death. I know, I spent 3 hours reading all the arguments prior to this post.

I agree that some 05 have not broken, and many other years have gone the way of the Dodo as well, but I'd rather just get it taken care of now regardless of whether or not I'm one of the lucky ones or not.