Halfshaft Bolt Answers (all threads merged)

[BlackICE]

Hmmmm, an opportunity.... Maybe I should pay for a full page ad in the New York Times, drive the price down on GT's, then buy a 100 of them next month.:cheers

You, would have to buy a lot of GT's to make up to the ad space, even at a 20K pop per GT.

 

[Gulf GT]

You, would have to buy a lot of GT's to make up to the ad space, even at a 20K pop per GT.

I figure I can drive the price down $50,000 each, since it's such a bad problem (at least it is till someone solves the problem). So, $5 million devaluation for the 100, then sell them back. I figure even with the ad costs I can net over $4 million. Hell on second thought, it might be worth it for me to fund the research just to fix the problem so I can get my profit back by selling them! I mean, I'm only talking about 2% of the Ford GT Market, that's not much right. Peanuts. Anyone catch my drift?

 

[Gimbal]

I have replaced the driver side bolts yesterday.
1) I have a 2006 #89 build date Nov 2005
2) Bolts were real tight and loctited with hard washer.
3) The bottom of the heads showed signs of being real tight, a little too tight I think.
4) I had absolutely no backlash between the axle and hub splines.
5) the inner VC joint does allow axial play. This is good and prevents large axial loads on the screws.
6) There is only about .030" distance between the top of the screws and the CV joint. There is no room for an extra washer and probably the reason one large bolt was not used.
7) It took me about 2 hours and 4 bandaids to complete the driver side. I highly suggest putting tape on the sharp edges of the heat shield first thing.
8) I used high strength M8x1.25 25mm long, not fully threaded and with a nice radius at the root of the bolt head. I had safety wire holes added. I used .041" dia safety wire.
9) I do have uneven gaps, small on driver side, 3x larger on passenger side.
10) I chose to torque the bolts slightly less than spec. Along with safety wire I used the blue loctite.
11) The hard washer showed no sign of bowing.
12) I'll do the passenger side next week.

Since I have no backlash in the splines I don't see a large twisting action happening to the screw heads. It sure would be nice to know why there are uneven gaps on some GT's.

I wonder if there is enough axial travel in the CV joint? If it hits its travel limit this could produce a large load to the bolt heads.

Seems to me Ford could figure this one out pretty quick. I wonder if Ford's loss of a zillion dollars last year is slowing progress?

 

[B O N Y]

Not wanting to sound like GT Joey.... however....
How many cars have had failures??? Bear in mind, my car was on the thin line, when I replaced at my expense the bolts and washers, one had backed off and the washer was concaved. Oh, poor me, I could have been stuck on the roadside... done feeling sorry for myself, ok.


Next, I was told by Rich, GT TECH (I find it annoying when sources names are withheld) that when he worked on the line, he replaced with the Riccardo rep the bolts and washers on every transaxle and off every car in the shipping area.


I appreciate the efforts that Kendall, Jay and others are taking studying the problem. I personally don't believe that management above the SVT level is aware of this 'issue.'


Meanwhile, going to the press, will be as productive as going to the husband of the neighbors wife that you are having a torrid affair with. It is not funny, plain dumb and will bite the whole community in the gonads.

 

[nota4re]

I used high strength M8x1.25 25mm long, not fully threaded

Where did you find these?

(Thanks for the great write-up.)

 

[dbk]

I personally don't believe that management above the SVT level is aware of this 'issue.'

They are. It's important for people to remember companies can't just issue on the fly statements about this kind of stuff.

 

[Gimbal]

nota4re, I searched the internet far and wide for many different bolts. I ordered half a dozen different types of bolts to choose the best one. I could have ordered a custom one but I'm too impatient to wait so long. My take is the strongest bolts are about 12.9 or grade 8, 170ksi to 200ksi. If bolts are breaking at 170ksi having a 200ksi is not enough increased strength and safety factor to assure no failure. I'm hoping the readius at the bolt head helps prevent fatigue failure.
I'm a little reluctant to suggest actual bolts to others, not only from a liability standpoint, but if a bolt breaks that I suggest I would feel real bad.

 

[B O N Y]

They are. It's important for people to remember companies can't just issue on the fly statements about this kind of stuff.

Thanks Dave. I will wait for more news.

 

[Gulf GT]

Meanwhile, going to the press, will be as productive as going to the husband of the neighbors wife that you are having a torrid affair with. It is not funny, plain dumb and will bite the whole community in the gonads.

Yep, and most of us have clear heads, but not everybody. It only takes one pissed off guy with the right connections who sells his car because it breaks and doesn't care anymore. And trust me, in this financial range a few of us have those connections. As it has been said before, it's taking way too long to solve the problem. Ford's baby could end up getting a major "black eye", and their legacy with will be tainted forever. I've already heard it from my old Ferrari and Lambo buddies, "what did you expect, it's a Ford". The word about the problem is already out and creeping around the supercar community. When Ford built this car they were swimming upstream already, any significant hiccup will only confirm that belief. Up till now, Ford has done a good job of quelling the "naysayers" by going out of their way to solve problems during production, i.e. the control arm. They just better not be thinking, "we've sold them and we're done", or all that fuss about the Ford GT being a "pacecar for the entire company" will be anti-climatic, and instead the whole project will confirm many people's belief about the company's capabilities. Make no mistake, this is a pivotal point in Ford's legacy, but like many companies, they might think with their pocketbook in the short term. Yes, if it's solved in the same manner as the "control arm" everyone will eventually forget about it, but if not, and the problem turns out to be a significant design flaw requiring large portions of the transaxle to be replaced, we all could be in for trouble. I find fate is interesting, greatest loss in company history at the same time as a possible "kill shot" on their "pacecar". Ford it's up to you, in 5-10-20 years people will say: "that was the nail in the coffin" or "they built one hell of car and turned the whole company around". If the "Ford GT Hotline" in any indicator, I'm very concerned. I only hope Ford understands that there is a lot more at stake here than just an out of production model and that the clock is ticking. We'll see.

 

[dbk]

I've already heard it from my old Ferrari and Lambo buddies, "what did you expect, it's a Ford". The word about the problem is already out and creeping around the supercar community.

I'll tell you what, anybody that says that has blatant problems with reconciling perception with reality. People judge domestic products under a different lens. That's a fact. You have an issue where the mechanical failure that results is a loss of drive. Contrast that with this:

If you want, you can even watch one of these new F430s burn to the ground:

http://www.youtube.com/watch?v=lQX0-uiY6Ko

Just do a search on the Ferrari board. How many modern Ferrari's end up as a crispy ball of metal on the side of the road? You can either a) enter into complete hysteria that it's a Ford and therefore this is some epidemic of poor engineering or b) realize the car was designed in months and still manages to NOT TURN INTO A FIREBALL DURING NORMAL DRIVING because the oil lines are properly placed, but has it's own issues. But Ferrari gets a freepass and building supercars is their only business?

I don't mean to somehow diminish the issue, but you absolutely never see this kind of uproar over the litany of serious problems with Ferrari or Lamborghini. Find me the "let's get a lawyer" or "let's start a media campaign" threads on those boards. Ever hear anyone talk about the Ferrari recall because the airbags might not deploy or the ABS may not work?

Why is that? Is it because of our obsession with some kind of strange domestic manufacturing self-loathing? Or is it just because the expectation is built-in that you'll have to spend tens of thousands of dollars maintaining the engine on a Ferrari because it will fail if you don't but a 212mph Ford should be more reliable than a Focus and you shouldn't dare have to spend $150 on a part kit to fix it?

Personally, I just don't get it. Like I said, I understand the issue is serious. Just like roofs flying off Z06s, and columns locking on Corvettes. It took what, 7 years before Chevy sent out the Column Lock recall? And Ferraris burning to the ground. I just ask that people realize analysis and rectification is NOT done in a day.

 

[BlackICE]

Or the new 599 burning up after its first drive from the dealer.

It seems the Mercedes McLaren SLR wasn’t the only supercar that was capable of spontaneously catching fire. Ferrari’s latest model, the 599 is also susceptible to getting a little hot under the collar. A 599 recently caught on fire during its first drive from a dealer in Germany, near Dresden. The driver escaped uninjured and has understandably been offered a replacement vehicle from Ferrari.

Previously, a F430 caught on fire due to a problem with a faulty oil line – that’s 2 burnt Ferraris in 2 months. The images were collated by fan forum Exotixboard.


http://www.motorauthority.com/cars/ferrari/buy-a-ferrari-use-the-engine-for-warming-your-hands/

 

[Gulf GT]

All you have to do is look at the sport of F1 or a "Road & Track" article to see that Ferrari and Lamborghini get free passes everyday. As I said before, we're swimming upstream.

The point here is that Ford has the chance to turn all that on it's head, right here, right now. That's the whole idea behind the Ford GT, right. It kicks their ass on the track, has no major design defects, and drives like a dream. Don't give em any ammunition. Just get it done, or that burning F430 could be a Ford GT that got run over by a semi because he couldn't get out of the way, but this time the occupants will still be in the car.

 

[Gimbal]

Gulf GT,

Right on!

 

[Shadowman]

I have replaced the driver side bolts yesterday.
1) I have a 2006 #89 build date Nov 2005
2) Bolts were real tight and loctited with hard washer.
3) The bottom of the heads showed signs of being real tight, a little too tight I think.
4) I had absolutely no backlash between the axle and hub splines.
5) the inner VC joint does allow axial play. This is good and prevents large axial loads on the screws.
6) There is only about .030" distance between the top of the screws and the CV joint. There is no room for an extra washer and probably the reason one large bolt was not used.
7) It took me about 2 hours and 4 bandaids to complete the driver side. I highly suggest putting tape on the sharp edges of the heat shield first thing.
8) I used high strength M8x1.25 25mm long, not fully threaded and with a nice radius at the root of the bolt head. I had safety wire holes added. I used .041" dia safety wire.
9) I do have uneven gaps, small on driver side, 3x larger on passenger side.
10) I chose to torque the bolts slightly less than spec. Along with safety wire I used the blue loctite.
11) The hard washer showed no sign of bowing.
12) I'll do the passenger side next week.

Since I have no backlash in the splines I don't see a large twisting action happening to the screw heads. It sure would be nice to know why there are uneven gaps on some GT's.

I wonder if there is enough axial travel in the CV joint? If it hits its travel limit this could produce a large load to the bolt heads.

Seems to me Ford could figure this one out pretty quick. I wonder if Ford's loss of a zillion dollars last year is slowing progress?

Your personal observations are well received.

Jay aka GTSaver.com and I chatted at length again on Saturday about this isuue and still remain convinced that the issue is random and has a lot to do with the fit of the splines. In your case since the spline fit was tight with no axial movement then I would suspect that you will not have any problems.

As for the lash in the CV; this would have no affect on the bolts breaking as the coupler is held into place with the two bolts as such will either have the axial load placed against the splines (as it should be IMO) or sadly if there is axial movement present because of loose spline engagement then the load will be placed against the bolts.

Lastly; as far as Grade 8 being the highest grade production bolts available I would like to introduce you to

L9® Fastening System- L9® Hex Head Cap Screw (318)
The L9 Fastening System is the strongest off-the-shelf fastening system available. It is a 180,000 psi minimum tensile strength (stress) assembly designed for high stress applications requiring high clamp load.
Alloy steel.
20% stronger than SAE grade 8.
Zinc Yellow dichromate finish.
Hardness - Rockwell C 38-42.

I have used these for years on critical suspension and driveline components

Takes care

Shadowman

 

[AMB]

Bolts

If you go to the ARP Website (www.arp-bolts.com) ; You will see that "140,000 psi-Yield Strength amd 170,000psi-Tensile Strength" is the MINIMUM REQUIREMENTS For their BOLTS!!!

AMB

 

[AZGT]

I know there has been discussion about the "soft" washer. But has anyone actually taken a broken bolt to check to see if it was hardened properly (is there a way to check one?)? Is there a chance we are dealing with bad bolts rather than something else?

I am having trouble unerstanding that even if there is extra play in some of the components like has been discussed, how would that shear the bolt head? Afterall, the bold to washer to half shaft would be "solid" with no movement when it is tightened, so where is this movement coming from that makes it shear? If the "washer" is moving, then maybe serrated insde the shaft and a serrated washer?

Now the idea of unequal gaps could suggest that maybe there is an inward / outward pull on one side that would be against the head, but again we are talking tensile strength, and it would take a lot to make it break that way.

Confused :confused

 

[Fubar]

I've already heard it from my old Ferrari and Lambo buddies, "what did you expect, it's a Ford".

How do your lambo buddies like the clutch on that Gallardo?

 

[Fubar]

Doesn't wiring the bolts resolve this issue?

 

[AMB]

Azgt

The STOCK bolts weak point is the full length thread!! The bolt FAILS where the thread meets the head of the bolt!!

AMB

 

[Shadowman]

I know there has been discussion about the "soft" washer. But has anyone actually taken a broken bolt to check to see if it was hardened properly (is there a way to check one?)? Is there a chance we are dealing with bad bolts rather than something else?

I am having trouble unerstanding that even if there is extra play in some of the components like has been discussed, how would that shear the bolt head? Afterall, the bold to washer to half shaft would be "solid" with no movement when it is tightened, so where is this movement coming from that makes it shear? If the "washer" is moving, then maybe serrated insde the shaft and a serrated washer?

Now the idea of unequal gaps could suggest that maybe there is an inward / outward pull on one side that would be against the head, but again we are talking tensile strength, and it would take a lot to make it break that way.

Confused :confused

I understand your being confused

The harder the bolt the less it will bend..... in fact at the extreme end of being hardened they will not bend at all but rather snap like a dried twig.

In the initial setup the washers were soft as such the movement at the splines (IMO) caused the washer to become deformed as such the torque applied to the bolt was lost and the bolts simply backed out over time. Then hardened washers were substituted which meant the bolt would take the load and then untimatly the head would shear off. Once again the bolt will not bend however it will also only take so many side load cycles before it shears off.

As for the splines being loose on some gals causing this; this is rather simple to share. The two bolts are designed to take "NO" load but rather to simply hold the assembly together akin to clamping the head on the block. The only way that there can be a load that would cause these issues is from axial rotation which leads to ........ your pushing your gal out of the intersection.

Use a garden variety wood nails as an example; at least once most have attempted to hammer one into a piece of wood only to have it bend and we often times smack it straight again and repeat the process. With a case hardened nail such as some concrete nails this could not happen; it will simply snap.

As for the OEM bolts being a full thread rather than a shoulder bolt (IMO) is not the issue as most torque to yield bolts are full thread because the process of applying torque is the act of twisting as such the entire piece needs to conform otherwise you will have a stress related torque area at the point where the threads stop and the shoulder begins. Will a shouldered bolt allow for more axial rotations before snapping; maybe but then there is a "HIGH" risk that when it snaps it will be at the thread/shoulder area and heaven forbid "IF" this is at or near the stub axle one may find themself shipping a transaxle to Ricado to have it disassembled so the broken off threaded postion can be drilled out.

I think the fact that the heads have snapped with full bolt extension in a crazy sort of way has been a blessing.

Shadowman