Halfshaft Bolt Answers (all threads merged)

[AZGT]

Thanks for the info. Naturally, one of the first things in problem solving is to know what the problem is. Of course you can accidently solve it by implementing a solution that happens to be the fix, but then it is more a matter of luck.

Anyway, taking your image (nicely done), this is something that goes through my mind. What if the "washer" was more like a pie pan and went all of the way out so that it was also secured by the six bolts holding the half-shaft to the axle (sandwiched in) plus the two main bolts. This would probably eliminate washer problems. Shear would be a different matter.

The other thought I had was what if there were some small nipples on the back of the washer that would center in to slightly tapered bolt holes in the axle (small countersink).

Last idea was a pin through the washer that would engage the splines so that there would be a plane (three points) instead of the two.

 

[quick time]

Half Shaft Issue in Automotive News

Ford GT has shaft woes

Harry Stoffer | Automotive News / April 2, 2007 - 1:00 am

advertisement


WASHINGTON -- Federal safety regulators have gotten four complaints about half-shafts coming loose in Ford GTs but are not conducting a defect investigation, Automotive News learned Friday. If the half-shaft separates from the transaxle, the rear wheels lose power.

The National Highway Traffic Safety Administration declined to comment.

Executives at Ford Motor Co.'s high-performance division acknowledged a much wider problem - at least 60 incidents of broken shaft bolts - but said it is not a safety issue. A spokesman says Ford issued a service bulletin on the car last year.

Jamal Hameedi, chief engineer of Ford's Special Vehicle Team, told AutoWeek that the failures occur during acceleration but not at highway speeds. Installation of replacement washers can prevent failure, Hameedi said.

About 4,000 of the two-seat, midengine, high-performance cars, priced at more than $150,000, were built as 2005 and 2006 models.

You may e-mail Harry Stoffer at hstoffer@crain.com

 

[BigsGT]

Before determining a fix it sure would be nice if we had some broken bolts to conduct failure analysis. There are other ways to preload the bolt other than the washer design so the bolt sees no fatigue inducing load reversals. If the bolt failed in the last engaged thread that would tell us a lot. I work with threaded connections in my profession and as Larry wrote any sucessful fix without knowing the root cause is just lucky.

 

[Indy GT]

Biggs, I agree as well.

As I have posted earlier (much earlier) the "root cause" should be first determined before mapping out a fix. To shotgun multiple fixes without testing is not my perferred course in addressing this identified problem.

Then too incorporation of these 3rd party fixes murkys the liability waters if the fix does not work which has previously been posted.

Is Ford IN FACT working on this issue???

 

[dbk]

Is Ford IN FACT working on this issue???

Yes.

 

[quick time]

Executives at Ford Motor Co.'s high-performance division acknowledged a much wider problem - at least 60 incidents of broken shaft bolts - but said it is not a safety issue. A spokesman says Ford issued a service bulletin on the car last year


To my knowledge Ford has never acknowledged the specific "half Shaft" issue in the form of a SB or TSB. What they did issue was a Service bulletin for "Leaking output shaft seals". Many owners have been able, with the help of their Service Director, to use this Bulletin to replace the existing bolts and washers pertaining to the half shaft issue but it does not "fix" the problem.
In fact the replacements parts are exactly the same as the existing parts except for the owners that did not have the improved, heat treated washers.
The benefit of doing this particular service bulletin is to see if there has been any indication of these bolts starting to back out or signs of excessive spline play. When the technician replaces the bolts hopefully he torques them correctly and then this whole procdeure can bring some peace of mind. However I think I recall that at least one owner who has done this replacement exersize has experianced a 2nd failure.
Until Ford addresses the specific issue of shafts coming loose and issues a Service bulletin for it I for one will not feel comfortable driving the car.

 

[Gulf GT]

I will not explain how I know, so don't ask.

Ford is definitely working on the problem full time. They did not take it seriously in the beginning because the failure will not occur at speed. It can only happen when accelerating from a standstill. When the car is propelled forward, positive action on the mechanicals prevents the failure from occurring at speed. They are close to a solution. They believe the root cause is the that CV cup and shaft don’t fit tight against the spline. They are working on a "shim kit" to solve the problem of the "rocking" movement that causes the two fasteners to break. They hope to offer a "kit" that will resolve the problem permanently soon. After my discussion, I feel confident that they are on the problem, understand what it will take to solve it, and are going to issue a solution that will work for all of us.

 

[Empty Pockets]

WHERE DO I SIGN UP!

Do you have any idea or guess whether they'll be sending out letters advising all of us of this fix when it's ready? One would assume that would probably be the logical way to inform owners. Or, do you think maybe they'll just go the TSB route?:shrug

 

[Gulf GT]

WHERE DO I SIGN UP!

Do you have any idea or guess whether they'll be sending out letters advising all of us of this fix when it's ready? One would assume that would probably be the logical way to inform owners. Or, do you think maybe they'll just go the TSB route?:shrug

Sorry, I don't have a firm answer on that. Likely will be a TSB.

 

[quick time]

I will not explain how I know, so don't ask.

Ford is definitely working on the problem full time. They did not take it seriously in the beginning because the failure will not occur at speed. It can only happen when accelerating from a standstill. When the car is propelled forward, positive action on the mechanicals prevents the failure from occurring at speed. They are close to a solution. They believe the root cause is the that CV cup and shaft don’t fit tight against the spline. They are working on a "shim kit" to solve the problem of the "rocking" movement that causes the two fasteners to break. They hope to offer a "kit" that will resolve the problem permanently soon. After my discussion, I feel confident that they are on the problem, understand what it will take to solve it, and are going to issue a solution that will work for all of us.

This is great news! thanks.

 

[Gimbal]

I will not explain how I know, so don't ask.

Ford is definitely working on the problem full time. They did not take it seriously in the beginning because the failure will not occur at speed. It can only happen when accelerating from a standstill. When the car is propelled forward, positive action on the mechanicals prevents the failure from occurring at speed. They are close to a solution. They believe the root cause is the that CV cup and shaft don’t fit tight against the spline. They are working on a "shim kit" to solve the problem of the "rocking" movement that causes the two fasteners to break. They hope to offer a "kit" that will resolve the problem permanently soon. After my discussion, I feel confident that they are on the problem, understand what it will take to solve it, and are going to issue a solution that will work for all of us.

Wow, this is hard to believe that as long as we are not at a standstill we should have nothing to worry about! What if I am doing, let's say, 2 mph and pop the clutch or give it a bit of gas? How about 5 mph, or 20 or 60? I do not believe it is not a danger at speed if the bolts should break. I don't understand how shimming will take up the slop in the splines, the splines themselves are not shimmable. If Ford designed a new hub flange that somehow tightened by squeezing the axle splines then maybe that would make sense. Let me say that just because I don't understand something doesn't mean it won't work. I just find it difficult to imagine.
Thanks,
Gimbal

 

[Gimbal]

What the heck? I tried posting at work earlier, the website locked up. I get home and try to re-write the same post from memory and wa-la the first one shows up with the second.

 

[AZGT]

I don't understand how shimming will take up the slop in the splines, the splines themselves are not shimmable.

I think (sorry - brain fart) that I mentioned this before. I remember that on my 1963 Corvette, the half shaft pressed against the read end, so to take it loose you had to mess with it (big block rear end, etc). One of the questions I raised was that if there was a pulling on the axle versus a pushing on the axle. Pulling could result in popping the heads off the bolt Push would possibly result in bearing wear.

If Ford it working on it, OK. Otherwise it is like we need a think tank and say "OK, what could cause the problem" and see what ideas people come up with. Realistically there are only a limited number of potential problems. Once you identify them, solutions can be considered.

A lot of it comes down to a question that I just recently posted of "is it shear or is it popping the heads off". Big difference.

 

[Indy GT]

Ford Fix

DBK and Gulf GT, thanks for the update and the information that the Dearborn engineers are working on fixing the root cause of the bolt breakage issue. I trust they will get it right this time. Besides who knows our drivetrain best?

I will cross my fingers and just wait for the Ford fix.

 

[Gulf GT]

All I would say about the speculation in the ability and interest for Ford to properly diagnose and find the right solution to the problem is, take a careful look at the engineering on the rest of the car. I think most of us were complaining here to get Ford to look at it, not because they aren't capable of fixing it properly. I've talked to these guys; they're the same as they were when they built it, same enthusiasm, and same ability. I would find it hard to believe that they would want their swan song to have an Achilles heel. That's not how all these guys want their best days of their entire work lives remembered, and Ford management certainly doesn’t want their supercar to be brunt of jokes for the next few decades. Even if you look at it from their point of view, they have a lot of interest themselves in making sure the car lives up to its legendary status in history. I think they'll do the right thing, they did on the rest of it.

 

[Empty Pockets]

I think they'll do the right thing, they did on the rest of it.[
/QUOTE]


THAT's an understatement of the first order!

 

[doccars]

Ford GT has shaft woes

From an article in the April 2, 2007 trade publication of Automotive News

"Ford Gt has shaft woes

Washington- Federal safety regulators have gotten four complaints about half shafts coming loose in Ford GTs but are not conducting a defect investigation, Automotive News learned Friday. If the half shafts separate from the transactional, the rear wheels lose power.
The National Highway Traffic Safety Administration declined to comment.
Executives at Ford Motor Company's high performance division acknowledged a much wider problem- at least 60 incidents of broken shaft bolts- but said it is not a safety issue. A spokesman says 40 issued a service bulletin on the car last year.
Jamal Hameedi, chief engineer of Ford's Special Vehicle Team, told AutoWeek that the failures occur during acceleration but not at highway speeds. Installation of replacement washers can prevent failure, Hameedi said.
About 4,000 of the two-seat, midengine, high-performance cars, priced at more than $150,000, were built as 2005 and 2006 models.
-Harry Stoffer"


This article is being furnishes as an FYI.

Personally I love my GT and feel despite these issues, Ford did a great job especially considering the complexity and time frame from concept to production.

 

[dbk]

Found this interesting on the Lamborghini site:

"Got about half way home and I hear a bang out of the back of the car. I immediatly let off the gas but everything sounded normal right after and guages were reading normal so I thought maybe there was something in the road I hit, but I did not see anything. I go to give it some gas and the RPM's rev as if the clutch was slipping. So I pull over (mind you its midnight on I-40 outside Kigman, AZ) and there is smoke everyhwere and oil running out the car like someone turned on a faucet. Finally at 1:30 the tow truck arrives and dives me back to phoenix which is a 1 1/2 hour ride in the lambo but 2 1/2 in a tow truck. LOS has no place for late night problems as this so we drop it at the house and I'm in bed by 5:00 AM. I'd been up already for 24 hours the night before, I was in vegas. Tow truck comes this morning and gets it apparently the same drive shaft bolts that came loose on teh superleggara last week at PIR came loose on my car and the bang I heard was te bolts coming out and hitting the and splitting the oil and power steering lines. Luckily there was no damage to anything else and parts on order. I guess this is becoming an issue from what I was told after talking DIRECTLY to the tech not the service idoits at the desk. There may be a recall coming out on the drive shaft bols o all '06 and '07's...............not sure if its going to happen but apparently its seems to be affecting many G's including the new superleggara."

http://www.lambopower.com/forum/index.php?showtopic=20350

 

[Silverbullitt]

Found this interesting on the Lamborghini site:

"Got about half way home and I hear a bang out of the back of the car. I immediatly let off the gas but everything sounded normal right after and guages were reading normal so I thought maybe there was something in the road I hit, but I did not see anything. I go to give it some gas and the RPM's rev as if the clutch was slipping. So I pull over (mind you its midnight on I-40 outside Kigman, AZ) and there is smoke everyhwere and oil running out the car like someone turned on a faucet. Finally at 1:30 the tow truck arrives and dives me back to phoenix which is a 1 1/2 hour ride in the lambo but 2 1/2 in a tow truck. LOS has no place for late night problems as this so we drop it at the house and I'm in bed by 5:00 AM. I'd been up already for 24 hours the night before, I was in vegas. Tow truck comes this morning and gets it apparently the same drive shaft bolts that came loose on teh superleggara last week at PIR came loose on my car and the bang I heard was te bolts coming out and hitting the and splitting the oil and power steering lines. Luckily there was no damage to anything else and parts on order. I guess this is becoming an issue from what I was told after talking DIRECTLY to the tech not the service idoits at the desk. There may be a recall coming out on the drive shaft bols o all '06 and '07's...............not sure if its going to happen but apparently its seems to be affecting many G's including the new superleggara."

http://www.lambopower.com/forum/index.php?showtopic=20350

The name was changed to protect the innocent. (Dragnet)

 

[K-P Garage]

awaiting word from Joey's GT parts house

I will await word from THE GTJoey and his birdie friends on this ever lingering issue. Down south here, we are just wrappin' those CV knuckles with barb wire to hold 'em together just fine!