If you've been following the Third and Fourth Gen F-Body Differential R&D 2012 Thread then you know that I've been working with Quaife to make a differential for 3rd and Fourth Gen F-bodies. I think we've got enough info and we've checked other manufacturers as well and it sounds like Quaife is the only game in town for a Helical Diff.

Quaife's diff will have a 3:1 bias ratio using 37 helix angle. It will be backed by Quaife's lifetime warranty which even covers race usage. The estimated cost is $1050-$1100/unit. Once 10 people express interest, I'll get the final pricing. We'll need orders for 15 units for Quaife to start production. Lead time is 8-12 weeks.

The group buy will go through me and when it comes time to pay for the units payment will be made to MLS Motor Racing (my company) via paypal. In the interest of full disclosure I want everyone to know that I'm not making a dime on this deal and I'll be paying the exact same amount as everyone else. Please keep in mind that I'll be on the hook for this deal if people back out after the order is placed therefore please be sure that you can/will follow through if you commit cause my wife will kill me if I end up with $30,000 of diffs.

Per John's suggestion, I would like to collect payment at the time we place the order.

Group Buy Members:
1. Eric (me): Committed
2. Brian (Too Z Max)
3. John Crouse
4. Mike P
5. Jason Swindle
6. Tony P.
7. Mark (Conemark)
8. Phil (chevy053)

Count me in. I hope this happens soon.

Eric you know I am in!!!

To protect yourself maybe you should take payment once you hit the numbers??

I'm in.

We are up to 5!

I'm interested, but don't always have $1k on deck at the drop of a hat. If the timing is right (in correlation to my quarterly bonuses) I'll jump on one.

I understand, so I won't include you in the count. Check out this thread at regular intervals to see where we are at with this and maybe you'll get lucky with the timing.

only for stock rear-ends ?
or does it also apply for a 9" or 12-bolt application ?

They (Quaife) may already make one for the 9s (but not sure).

Wavetrac makes diffs for BOTH the 9s and 12 bolts though.

how would this compare to a high-bias TrueTrac 31 Spline diff with Preload ?

This group buy is for stock 3rd and 4th Gen F-bodies with 7.5 rear ends. I'm not sure if Quaife makes diffs for the 12bolt and 9 inch, I haven't checked into it.

I'm not sure of the TrueTrac's bias ratio (for some reason 2:1 comes to mind, but don't quote me), but during my search I found their warranty info which states that motorsports voids their warranty. Quaife's warranty on the other hand does apply to motor sports applications.

If someone would like to call Eaton and find out the bias ratio please post it up in our "Diff R&D" Thread

Not trying to poop on your parade, but the wty isn't promising a replacement if you race with it and it wears out. In their wty exclusions, Quaife says: "2. which is degraded, damaged or deteriorates due to fair wear and tear within parameters of high performance use; or"

So if it just "worn out", like the other helix diffs seem to do over time, will they still cover a full replacement? It doesn't sound like it. It sounds like they wty against catastrophic breakage/failure due to mfg defect, not normal racing use. Now if they promise to send me a new diff for ANY issue, that would be different...

Yea they don't, nor would I expect any manufacturer to replace any part that wore out normally. But if the case fails they will replace it unlike other diff manufacturers.

I guess, the real issue here is what they consider "normal wear and tear".... Wear to the case? Enough wear on the worm gears that the bias ratio is 2:1????

Thanks,
Jason S.

Quaife does make one for the 9" according to their website.

This is a very good point. I'll contact them tomorrow and get clarification

We are up to 6!

Make that 7

Just got off the phone with Quaife. There definition of "normal wear and tare" means that the gears have worn down to the point where they no longer work as designed. However they have never experienced this issue with any of their existing units. Typically their warranty claims are for catastrophic failure, which they do/will warranty (as long as you don't send the ring and pinion through the thing first).

Anyone know why their diffs never wear out the helical gears like the Eaton/Auburn/Whatever? Better steel? Better overall design? Better gear tooth design?
$1k+ is a big chunk of change, but I'd go for it if I knew better why the Quaife is so "great", and not just more unfulfilled mfr promises.

That sounds good to met Eric. Thanks for the effort on your part!

Todd, my educated guess is that they're using harder, more durable steel alloys which will also be harder / more expensive to machine.

Jason S.

They DO have a GREAT rep as a manufacturer of pure race diffs and gearboxes of all sorts (mostly for Euro/Brit racing series classes, but also for Vette and Viper diffs).

I have no idea what the actual grade numbers of the steel they are using are, nor which heat treatments they use to ensure the strength/longevity of their diffs, though.

We're kind of stuck at 7, we need a few more people. If you're reading this and you think you know someone who maybe interested please reach out to them.

You can count me in and put me on the list.

Woohoo, that makes 8. Almost there!

Just curious, is this posted anywhere else?

No I only have it posted here

I posted a link to it on the CMC Forum.

I'd love to get in on this, but I can't make a commitment until the end of March (I need to see what my 1st quarter numbers at work look like).

I'm going to keep this group buy open until the end of March. If we don't have enough people signed up by then I'm going to close this group buy.

MLS,

Please, do not close the thread. There are some guys, like me, that are waiting a few days more. In my case, here in Mexico, by the end of april, after tax declaration to IRS (SAT here) , gives you back money as adjustment. I really want to be in the list, but I can not by this month.

Please, consider 30 to 35 days more, I am sure 3 to 4 more will come into the list, based on the comments written, and maybe on those extra days, the 15th will be reached.

Thanks.

Rodolfo Lara Pohlenz

I agree, keep it going a little longer, we are so close. I might even be willing to buy a second one to sell later to someone else.

Ok, we'll keep it open for another month and lets see what happens.

I'm definitely interested. With that said, forgive me for asking: why should I assume this diff, at twice the price, will last longer than the Eaton and Auburn Racer that my 4th-gen has already destroyed in short order? That's a serious question, not a smarta$$ one. At this point, if I can't find a diff that will live for at least an autocross season (10-12 events) before a rebuild, I'm probably going to sell the car. I'd like this to be the answer, but before I put money down I figure mentioning my concern is reasonable.

If you guys can alleviate my concerns, consider me in.

I’m just a bystander, but this diff will use the angle of the helix gears to create the high TBR ratio. The T2R from my understanding has a clutch pack that provides additional TBR over the standard T2. Without any clutch pack the diff should have a constant TBR once broke-in without anything to wear out. At some point the gears themselves will wear out of course, but in an OEM application this would probably be 200k+ miles on the original dino oil type situation.

Quaife knows their stuff, and I'd trust that they can create a lasting diff.

Remember it has a lifetime warranty, and that includes racing.

MLS,

Please, now, count me in. Ready to be in the list.

Rodolfo

Count me in got a great tax return, that should make 10.

Mark

Okay, I'll bite. Count me in.

Wow, we've got 11. Ok let's see if Quaife will move forward with 11. I suppose I should message people who signed up earlier to confirm they are still interested. Stay tuned.

Yes, even though I just installed a true trac, I am still in.

Hey Guys, bad news. Because it took us so long to get to 11 Quaife won't start production until we get to 25 now because they feel that if it took this long to get to 11, it will take forever and a day to sell the remaining 19 units.

CARAJO!!!!!!!!!!!!!!!!!!!!!!

I can not believe the logic Quaife is applying to this matter..... They are not even investing a cent on the advertasing (labor that MLS was performing on this and other forums), talking about the Project GM 7.5 Diff.... For sure, at the moment this product is offered, It will be known, and will talk for itself on the reliability department., based on the fact that the F-body market is a potential one just by amount of units.

Anyway, MLS, thank you very much for the help and time spent on this... If you hear that Quaife is going to change its reasoning, please, let us know.

Rodolfo

Major suckage. How long do we have to get to 25 units? Thanks for your work on this Eric.

Jason S.

They didn't give a time table for achieving the 25 mark. They probably don't care because if they sell all 25 in one shot then the 5 remaining units will already be paid for by the profits of the first 25.

I take it this will work with any stock or aftermarket axles?

The "number of potential units" must not mean a DAMN to most manufacturers out there it seems.
Either that, or we really are as 'rare' as MKIV Supras, despite the actual build units saying otherwise.

So many manufacturers STOP dead at making aftermarket (even OEM replacement stuff like weatherstripping and such) products for either post '92, or post '97 f bodies, or flat out REFUSE to make anything past those years, one would think that there are NO MORE LEFT AT ALL!!!

I am in still if something changes. I bought a tru trac and I am very happy. Now lets see if it holds up. My car was really pushy at first, but after 8 events it loosened up a bit and my car is handling much better.