Hello

Well I went to the track this past sunday to try out the new OZ700 clutch. Which by the way feels just like stock on the road and on my first two passes seem to grab great.

Temp was about 62 with a 30-35 mph head wind. DA was about 700 to start with.


On the first pass I did ok burn out launched at around 3000 rpm ( I wasn't ready when the lights started) and got a 1.70 60' with a 11.8 @ 118 mph. It was ok but my mph was off I nomrally run between 122-124 mph.

On the second pass I did a better burn out DA was about 900 by this time. Launched about 4500 rpm with a 1.60 60' and ran 11.6 @ 118 mph. Better time but the mph is still off. HMMM!

Anyway on the last pass temp dropped to about 55 and the DA when down to about 500. I did burnout John Force would be proud off. Nailed the launch at 5000 rpm and BOOM! the car went 2 ".

Well after towing the car back to LG's we noticed the rear case was cracked and when we removed the cover noticed all of the gears were trash. No I have a question since this has never happen to me. What happen? I have the DTE Brace, Harden shaft (both sides) and I was running 16" ET Streets with about 14-15 psi. What could I have done to prevent this? Someone told me that the 4.10 gears are to thin and that this seems to be somewhat common. Is this true, if so what gears do I go with????????

I love drag racing, but this is my third time to break in 1 year. Granted the other two times were both the short side (passenger) shaft, which is now harden. But I am trying to make the car as strong as possible. I mean there are a ton of cars running faster and with more HP than I have not breaking as much, what I am I missing.

Thanks for the shoulder.

 

ET streets or drag radials? Ouch! Sorry to hear, reread the post. The keys to keeping trannies in the car is not hitting the tires hard. No long burnouts to hard dry hops and launch slipping the clutch.
Phil

 

Sorry to hear it. The higher the ratio, the more teeth that have to be on the ring gear. Thus thinner / weaker teeth. IMHO 3.73 is the limit with an A4 and 3.42 with a M6.

 

The 4.10 gear sets are no less durable than any of the other ratios offered in the aftermarket, nor are they "thinner" as the false wives tale is often told/re-told.

In the old days, (solid axle and conventional standard rotation IRS differentials) in order for the manufacturer of the gear set to make the numerically higher gear fit into the case, they would have to manufacture the ring gear with a thinner mounting saddle for proper ring gear-pinion shaft positioning.

The C5 Corvette Getrag differential is *NOT* like that in any way. Not only is it obviously not a solid axle, but it is also is not a conventional standard rotation assembly either. Therefore, what worked/applied for the old-school differentials, absolutely does *NOT* apply for the Getrag unit...at all.

The ring gear mounting saddle is the very same thickness from the 2.73 all the way up to the 4.10, only the pitch of the ring gear/pinion shaft teeth have changed to change the depth relationship between the two.

So when someone tells you that the C5 Corvette 3.90 or 4.10 gear sets are "thinner" and "weaker" or whatever, tell them they are completely full of B.S., because that is just not the case in any fashion what-so-ever, in any shape or form. That's just internet "expertisim" at it best.....


What does happen with the use of lower gear ratios is however, is that the case assembly is subjected to increased stresses that are not nearly as predominent with higher ratios from the O.E.M. That's why you see someone go round after round with a stock diff, but blows up a 4.10 equipped diff. much sooner when it's not properly built for it...especially with stiff-sidewall drag tires.

Also, the weak, O.E., cast pinion shaft support often deflects very severely during a hard launch, which causes the pinion shaft to walk away from the ring gear during hard acceleration. Once this occurs, the tooth contact patch surface area of the ring gear/pinion shaft relationship is significantly decreased, while the shock loading is significantly increased at the same time. Something *HAS* to give and you get what happend to your differential.

This exact, very reason is why we have been preaching to everyone for so long to upgrade their differential with our billet aluminum pinion shaft support to protect against this. Often times unfortunately, the user thinks they are covered "good enough" with only HD output shafts, but that is certainly not the case...

This is why the new 2006 Z06 differential has heavier duty output shafts, pinion shaft supports and clutch pre-load springs, because they knew where the weaknesess are and have made an effort to fortify those areas. (We've been already producing these HD parts for 3 years now BTW.....)

Your engine *WILL* find the next weakest link eventually..... Hope you get your car back on the road swiftly and if we can be of service, please give us a call.


Best Regards,
DTE

 

dte, good info

 

.....................

 

 

The Automatic by Rodney (RPM Transmissions)

 

This exact same thing happen to me about a month ago. I had the DTE Stage two diff but it decided to go anyways. Second one in a year and no money to replace My case cracked as well. Good luck with yours. Kaley

 

Well now, I have two issues with DTE's reply. One, to increase the ratio from 3.42 to 4.10 you either have to increase the ring gear teeth count by slimming the teeth or increasing the size of the ring gear so you can fit more teeth (which you can't do because a larger gear won't fit in the case), OR by decreasing the size of the pinion gear. Most of the time it's done by decreasing the size of the pinion gear. That's why Getrag does not recommend going beyond a 3.73. Changing the ratio does not change the way they rotate or whether they are an IRS or solid. Talking about that is just throwing dust in the air to obscure the real issue. Two, drag racing tires have SOFTER, not stiffer-sidewall tires, hence the name wrinkle walls. More dust. The real issue is that when you try to put more power to the ground you will find the weak link. If it's not traction loss by spinning the tires, it'll be something else.

The Vette rear end will be a weaker link when you change the ratio.

There are things you can do to protect it, but, IT WILL BE WEAKER. A brace will help. Gears designed for drag racing will help (by bending instead of breaking) but will need to be replaced more often. Sorry for the long reply.

 

it seems somewhat ironic that first dte sells us the brace to prevent this, but when that doesnt work now this isnt enough you need to buy their pinion support. Whats next to buy from DTE to prevent their $1200+ diff from exploding? My 100% stock internal 4.10 is still holding up fine to over 200 11 and 12 second passes w/o any of those parts cutting 1.70-1.75 60' times on BFG Drag radials.

Dave

 

You have a good point. The first time my DTE rear end went they stood by their product. Now 6 months later and the second one goes completly (including the case) I can't get a response to my emails. I am a little fried that I am out $1500 bucks but I still think that DTE has a very well built product. Kaley

 

First and foremost, all 3 of you should read the text of the original poster first a little better before you respond so someone doesn't have to correct you later... For example~

Believe what you wish, as we're sure *you* have more experience with building the Getrag differential than we do..... There are always folks like you that like to argue the point in the other direction, despite the obvious fact still remaining; but that's o.k., because this is America. Whatever you choose to believe or not believe as "dust" is your perogative, but the unavoidable, physical truth of the matter still remains. Thanks for your input just the same and I'm sure the original poster appreciates it as well....

Only partially correct... The original poster stated he used drag radials, not drag slicks...big difference. Drag radials have a very stiff sidewall that does not flex much and they are designed that way so they can be driven on the road...DOT regulations. Therefore, they transfer a greater amount of shock to the drivetrain in all aplications. We will agree with you however, that full racing slicks do have a softer sidewall because they do not have to conform to DOT standards and as a result, they wrap up on acceleration effectively absorbing the shock load during a launch~ reducing the shock load on the drivetrain. It's really quite simple and everyone already knows this. It's just too bad we had to explain it all over again to retort to a post like this...

We already said this VERY clearly........

If you are going to bash and flame by joining on this "bandwagon", when it's not even our deal, at least be totally truthful to explain your entire situation with full disclosure, instead of only stating one inaccurate side... If you would like us to present the real truth about your situtation here on this public board, we will certainly do that in our defense, but we really don't think you'll want that because the result will accurately correct you multiple times, making this statement of yours appear very foolish and foolhardy. We treat all our customers fair, but for some, the keys to the shop are just not good enough.... It's your call......

Again, why did you still refuse the differential strut even thought we suggested it to you both times?? Trying to save yourself money in the short term both times, has cost you more money in the long term....both times.

Wrong.... As we've stated before MANY times now, we'll repeat it again. The differential strut is designed to provide additional transmission/differential case structural rigidity; *NOT*, we repeat again, *NOT* add additional internal component strength. Why do folks keep trying to use this as ammo against our product, when we clearly state otherwise, is beyond us....

As we already stated many times before, your engine will find the next weakest link in any drivetrain combination. Racing is racing and parts will always break eventually, no matter who builds/produces them. Most already know this, but some still refuse to reason with simple logic even though it stares them in the face everytime they venture to the track. If one can't afford to drag race knowing this, than they should not race at all, because the physics of the activity will *NOT* change just for them....

Read the original poster's text more clearer... He did *NOT* have one of our differentials, only HD shafts of some sort and our differential strut.

You mean the one that we refused to peice-meal together for you when you wanted us to a while back because we told you it *WOULD* whine prematurely? You know, the one that is whining very loudly by your own admission in other past thread posts elsewhere around here?? We're certainly glad we trusted out better judgement about that one by not half-assing it together like you wanted, otherwise you too would probably be trying to claim warranty, even though we informed you against it. Corvette's of Houston treated you unfairly when they built your differential, not DTE by us declining not to piece it back together for you. We don't build differentials that way and NEVER will.

What emails? You have sent nothing, nor have you even called us about anything!!!! Yet you blatently lie about those actions here to hedge your "bandwagon" jumping??? Not once in the last 5 months or so, have you even made contact with DTE in any capacity, so why would you go on a public board and lie about that just to make us look bad??? As we stated earlier to you~ If you would like for us to make public your previous differential debacle on your end, we will certainly do that to defend ourselves if we have to. It's your call, but at least don't lie about what did *NOT* take place!

 

I had a similar situation with 3:73s, cracked case but in an odd area (?) speedshop took apart and said they would discuss with manufactor becuase 4 or 5 adjacent teeth sheared....good news was manufactor agreed to replace unit...good luck

 

I was running on 16" ET Streets with 15 psi. NO DR's here I have learn my lesson there to many times. I do a good burnout and I don't dry hop. I guess I can cut back on the burnout, and I need to learn to slip the clutch.

I want to think you guys for your replies. Please keep them coming as I need to decide where to go from here.

 

The bottom line is this (and this has been repeated on this board to death)~

Racing is racing and components will always break eventually from fatigue, no matter who builds/produces them. This is why *any* HP parts manufacturer who's components are used in racing applications does not provide any sort of warranty for the item, other than for proper fitment or manufacturing defects. This lack of warranty for such things as axles, driveshafts, blowers, heads, blocks, transmissions...whatever, does not mean their product is inferior, it just simply means that they know the kind of abuse racing stresses place on a product and that anything metallic or otherwise will eventually fail due to fatigue. Racers already know and accept this and figure replacement parts in their budget. The physics of racing will not change for the Corvette owner just because we own Corvettes- no matter how much we would like them to. Therefore for the Corvette racer, if it's not in one's budget to replace parts when they break, than they should consider choice to not race at all. As in all types of racing, the laws of probability will always catch up to you at some point and something *WILL* eventually break and there's no way around it.

 

GUYS, GUYS, GUYS, -
There is no CRYING IN DRAGRACING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!
First everyone who drag races has to realize that they are risking CRASHING, BREAKING, or WORSE when they go to the track and "BEAT THE CRAP OUT OF THEIR $50,000 PLASTIC TOYS"!!!!

THERE IS NO CUTTING CORNERS IN THIS SPORT!!!
The High Horsepower guys usually have a ton of $$$$$ invested in the "GO FAST STUFF" so they are always searching for things that can HELP prevent breakage. That is where DTE comes in. Nowhere else will you find the technology that will help you keep your junk together!!!

I have DTE go through my rear end EACH YEAR and bring it up to date with anything new! I have FLP go through my transmission EACH YEAR and do the same thing! I change my oil every 2 weeks with Royal Purple Racing 41 (at $10.00/Qt.), I change my blower oil once a month. I run 28" tall ET Streets to get the MOST SIDEWALL to soften the launch. I run an automatic for consistency and ease of launch. Before the first run at every outing I make sure the ENGINE AND DRIVETRAIN are up to operating temp. especially in the cool spring and fall when the motor is making the most horsepower. In the hot weather I put a fan on my rearend and tranny to "bleedoff" as much heat as possible in between rounds.

In 2005 I got 113 1/4 mile runs on my setup. On labor day boost got past a check valve and caused my tranny line pressure to "spike" taking out my 3rd gear clutch drum! S@!t Happens - so you fix it put another valve in and move on!

If you have 400 RWHP or 1000RWHP and go drag racing on the street (BAD IDEA) or at the strip be preparred for stuff to break - so fix it - check to see if there is something better or stronger - use it - and GO BACK TO HAVING FUN WITH ONE OF THE BEST ENGINEERED CARS IN THE WORLD!!!!!!!!!!!!!!!!

JR

 

DTE: Are you a politician? Your reply:

Believe what you wish, as we're sure *you* have more experience with building the Getrag differential than we do..... There are always folks like you that like to argue the point in the other direction, despite the obvious fact still remaining; but that's o.k., because this is America. Whatever you choose to believe or not believe as "dust" is your perogative, but the unavoidable, physical truth of the matter still remains. Thanks for your input just the same and I'm sure the original poster appreciates it as well....


doesn't say anything about the true issue I brought up, that to make a higher ratio rear gear set, the pinion gear is smaller, and weaker. As for my experience in building Diffs, I have none. I did, however, do my homework when I wanted one, and bought a new Getrag built 3.73:1 diff. It has been in for 5 years, works flawlessly, with many trips to the dragstrip. My point was that anytime you step further away from the initial design parameters you risk finding the weak link. Putting 4.10's in the Getrag Vette diff ends up with a weaker unit. Period. It was designed as a 3.42 or less, and Getrag conceded it was OK with a 3.73. Anything steeper, you are on your own. Telling people your 4.1 is as strong as a stock unit is wrong.

 

6speeder~ No politicians here, but we do agree with you on two issues, but we again have to correect you on two more since your post was directed toward us...


Agree: We agree, the pinion shaft has one-less tooth on the 4.10, compared to others.

Disagree: We challenge you to actually present here, for everyone to see, your empherical, direct-experience, hands on data that proves the MG 4.10 pinion shaft is "weaker".


Agree: That speaks for itself with all due respect.

We could also do our "homework" and "research", read books, etc. on how to perform medical surgery, but we would by no means have even a clue as to what were were doing compared to a professional that was educated/trained to do such endeavors for a living every single day....


Congratulations! We hope your luck holds out.



Disagree: Again, read our post a bit clearer next time so you don't have to be corrected... We did *NOT* state our 4.10 differential was stonger than the O.E.M. unit. We *DID* state that there is no strength difference between the 2.73 and 4.10 *GEAR SET*, that's all, nothing else.... In fact we *DID* already say a few posts ago that the differential case does experience added stresses with the 4.10 gear set installed, so why do you continue to argue with yourself and with us when we agree with you on that issue?????


All that we did was give an answer to the original posters question, based on our direct, hands-on experience in building these differentials for years... We did not intend, nor wanted to go after anyone personally, but we found we had to, just to defend ourselves against a differential issue that was not even our own.

Arguing back and forth serves no real constructive purpose on the internet and it never will, as most folks have their pride to protect. If you choose to accept the information we present here for you, fine- it's to your benefit. If you choose to disregard the information we present to you for whatever reason and call it "trash", that's fine too- we still tried to help and ultimately, it's your differential, so do what you want. It makes absolutely no difference to us and regardless if you accept what we inform you about or not, the un-equivocal, un-escaping, physical facts of the issue will always remain despite your "position" of belief. Good luck!

 

A fresh question relating to earlier quote:

Does the C6 non Z06 rear assembly differ from 04 and if it is the reinforced design can it be bolted into a C5?

Thanks