Halfshaft Bolt Answers (all threads merged)

[AMB]

Yes, it should be a "8" not an "6", I corrected it,THANKS!!!

AMB

[analogdesigner]

Analogdesigner / Jay,
I have read & understand your assessment and agree with your conclusion on the tolerance or lack of tolerance being the real problem and fatiguing what ever fasteners that are in place. A larger center bolt would have a better chance of survival in these circumstances. It appears that Ricardo uses this setup on the Lambo. BlackIce's post # 258 refers to an old Abolfaz post and has a link that shows an exploded view of the Lambo set up.

Have you thought about this solution? Instead of forcing these small bolts to contain the deflection how about replacing the solid hardened washer with a wave type spring steel type washer or plate ? The bolt would be different in two ways. The bolt would have a smooth shank in the area where it would contact the spring and may be fractionally longer.

The bolt would be screwed into the tapped shaft holes until it bottomed out. Replacing the solid washer with the spring plate or spring washer would create a small air gap and allow this minute rocking to occur and not transmit the load to the bolt. The bolts would be bottomed out and would be held in with in with a Loctite "Red". This set up would allow the drive flange to float, the bolts and spring plates would keep it from walking off the shaft. The other fixes are going to be expensive for someone ?? I have some other ideas if you want to talk. It's sad we need to spend this much time on this subject. We all now wonder if we're driving a time bomb waiting for the car to break down?? Regards, Brian

Hi Brian,

Sorry for the late response. I have some designs that will be computer analyzed by this weekend. I am calling Ricardo late tonight in an attempt to purchase some replacement parts.

There are other forum members with good ideas because they understand the cause of the problem.

Thanks,

Jay
(949) 366-1211
www.gtsaver.com

http://www.fordgtforum.com/forums/forumdisplay.php?f=34

[Gimbal]

Hi Dave or DBK. I have to disagree that if the shaft comes loose it is not a saftey issue. It is an extreme saftey issue for sure. As I was pulling out into traffic this morning I was really hoping my axle did not break so that the giant truck coming at me would not slam into me if I got stuck powerless in his lane! Ford should take this issue to the top of their list of things to fix before someone dies!

[glord]

I'm not sure if there have already been previous posts on this but I just had a conversation with my dealer and he informed me that he just received a memo from Ford stating that Ford would only approve warranty replacement of the bolts should they actually fail.

Also of note is that according to the dealer the "new" bolts are no different than the original parts. He said that according to his sources the part number changed only because the parts are now being bundled under a single part number.

Given the fact that the bolts have not changed, and given Ford's lack of willingness to authorize a proactive repair, would suggest that Ford does not yet have a viable fix.

At the point the best we can all do is to take steps to make sure we have an uncompromised, properly torqued setup. On our own nickel in most cases.

[HHGT]

This is a direct quote from Ricardo regarding the Trasaxles:

"I realise that these are not typical figures for replica cars, but in our
line of business we cannot afford to release anything that is not state of
the art." Did that include the half shaft porblem?

This quote was posted on the following link:

http://www.gt40s.com/forum/gt40-tech...transaxle.html

I also found the following threads posted on the same site. One of the interesting questions asked was the half shaft angle!

http://www.gt40s.com/forum/gt40-tech...+shaft+failure

and

http://www.gt40s.com/forum/gt40-tech...+shaft+failure

[Craig]

Interesting that the photo in the above link shows a single large bolt holding the flange to the transmission. I wonder why they deviated from what they knew worked. There most be some reason, and I doubt it was cost driven. There just can't be that much difference in cost.

Craig

[BlackICE]

There just can't be that much difference in cost.
Craig

The two bolt attachment would cost more than one big bolt. There must have been a good reason for the additional cost.

BTW Craig, thanks for the Fe.

[HOGDEALER]

This is a DRAG!!! I do not want to drive the car and get standed. I guess I will just park the car. Just another trailer queen.

[AZGT]

Last weeks Autoweek (The one with the BMW on the Cover) said they are looking for feedback from owners of several cars. One os the cars is the Ford GT. Maybe we can all chime in and get the Halfshaft problem some more light. Someone must be able to come up with a fix for the problem. I do not feel comfortable driving a car that might fail at the next light just as the logging truck runs over me and the blue oval

IMHO I'd be a little careful about going "public" with the axle bolt issue. Like one of the other members said, at the moment we have an "issue" to be solved. I would think lots of national publicity would do more to shy people away from the car (resale issue) than fixing the problem. Both Ford and Ricardo, and a lot of guys on this board, know about the problem and are trying to come up with solutions. It is only a matter of time, then the issue will be gone. Major publicity would hound the car even after the fix is in place - just like how we all hear about the a-arm problem that is no problem (in fact, the fix is even better looking than the "normal" a-arms). Sometimes it is better to keep "dirty little secrets" inside the family until the problem is solved.

Just a thought.

[nota4re]

My esteemed colleagues,

Perhaps in parallel (I sincerely hope) to what Ford is doing to resolve the problem, I wanted to let everyone know that I am consulting with what is one of the top EXPERTS in the world when it comes to half-shaft and hub designs. This individual is founder and owner of a company that has been number one in their industry of supplying space-age, bleeding edge, half-shafts and hubs to Formula 1, CART, Champ and various other racing organizations. Both their engineering and manufacturing capability is truly state-of-the-art and perhaps literally without peers. The owner has been in the hub & half-shaft business for more than 40 years. He has seen it all.... and he is relied upon by many current Formula 1 teams to continue to push the envelope. I honestly believe that if Ford and/or Ricardo developed a list of 3 people in the world to consult with on the problem and fix, he'd be on the list. No doubt. Ironically, he is also an owner of a Blue/White '05 GT and until I met with him, he had never heard of the problem. (Unfortunately he’s not a member of this great forum.)

Anyway, we met for over 3 hours last week with many pictures, descriptions, and experiences that I had captured from these forums. He has been a friend of mine for several years but only recently did the increasingly dimmer light bulb in my head click on to make the connection.

He is not an arrogant man, nor is he a man to condemn other designs or presume to be "all knowing". However, he believes he "sees" and understands the problem and why it is occurring. He asked me to look and gather some additional measurements from my car after I returned home - and all seemed to be fully supportive of what his failure assumptions were.

Frankly, this is the easy part and I have no doubt that Ford/Ricardo is already "there" too in understanding why the problem is occurring. A more difficult problem is determining a resolution that can be retrofitted to cars in service without requiring removal of the transaxle. Even more complicated than this is having a fix that will work with all cars when there is likely car to car tolerance variations. So, for example, he is relatively confident to be able to develop a solution based on the tolerances for my car... but we may likely need to have some other cars to guinea pig to know if a solution has broad applicability.

With the constraints of not requiring transaxle removal/dis-assembly and with finding a broadly applicable solution (in contrast to a single car fix), the resolution is not going to be easy. The good news is that he is on-board to help. Other good news is that he often consults with a semi-retired individual who is a household name in Formula 1 engineering circles. A legend. He is roping him in too to have a look.

Both individuals are “contributing” out of the kindness of their hearts and because they are enthusiasts like ourselves.

Any progress we may make on the topic is on hold for one week as my contact is out of the Country on a hunting expedition. I hope to have more to report within a couple of weeks and I will keep everyone abreast of our progress. Once again, I sincerely hope that this effort – with literally the top experts in the world is in parallel with what Ford/Ricardo may already be doing.

I have hesitated to post or say anything because I am reluctant to set expectations. Anything is possible including the fall-out of these participants…. for any number of reasons – their schedule, legal issues, etc.

I wanted to provide this update, however, to say that the pursuit of ARP bolts as a singular resolution is on hold. I have no doubt that superior fasteners will be needed in an eventual overall solution, but I no longer want to distribute bolts as a viable singular fix.

I will keep the group updated on our progress and in the interim perhaps Ford, Jay, or John (Accufab) may have a resolution or alternative available. The good thing is that there are a lot of people working on this – and I have the utmost confidence and respect for the experts I have contacted.

More – as soon as I have it.