Halfshaft Bolt Failures and Customer Satisfaction Program


Swazi

GT Owner
Mark II Lifetime
Jan 9, 2006
34
Northern California
just had this done today by frontier ford in santa clara. i was the 3rd or 4th GT they've worked on already, and they seem very familiar with the process.

in general they seem to be a good place to get work done on GT's since they seem to have a lot of them go thru there. i've met both the GT techs there and they both seem quite knowledgable.

the new washer appears more than twice as thick as the old ford washer. sorry i didn't have a camera with me.

the new bolts have a hex, i.e. non-allen head on them.
 

Joehand1

Tungsten GT Owner
Sep 20, 2007
589
Hattiesburg, MS, USA
Not all dealers will work on a GT, and the sevice quality varies greatly at those who do. I would check with other forum members about recommendations in your area.

Mine is presently at Treadwell Ford in Mobile getting the bolts changed, as the local Hattiesburg dealer said they wouldn't touch it. (They called today and told me every bolt broke as they were removing them, so anyone hesitating to get the repair should get it done ASAP! This is a real problem, but Ford is taking care of it.)
 

Accufab

Well-known member
Mar 14, 2006
142
Rear axle bolts

Sorry, haven't been on this site for awhile. I read all the posts on the rear axle bolt issues that many of your seem to be experiencing. I would have responded on one of those threads but they were locked or closed. Anyway, we have sold over 200 rear axle bolt kits to date. We have never experienced a single failure with one of our bolts. And this includes several cars with HP levels between 850 and 1100 rear wheel horsepower. Just thought that you should know.
 
Aug 25, 2006
4,436
Sorry, haven't been on this site for awhile. I read all the posts on the rear axle bolt issues that many of your seem to be experiencing. I would have responded on one of those threads but they were locked or closed. Anyway, we have sold over 200 rear axle bolt kits to date. We have never experienced a single failure with one of our bolts. And this includes several cars with HP levels between 850 and 1100 rear wheel horsepower. Just thought that you should know.
This is a very timely and well received post

I have installed numeous sets of the AccuFab halfshaft hardware and continue to do so with no failures not to mention the fact that I like the head design of the ARP hardware much better than the OEM style. I share this even though I have presently in my facility no less than 4 sets of Ford's latest halfshaft hardware.

My position remains as follows and as I share with all of my customers; I respect and truly appreciate that Ford brought to "ALL" the new version of the halfshaft hardware through a campain process however considering that this is at least their 3rd attempt I will not subject my gal or those of another to a product with a yet to be determined track record. Instead what I have and am doing is giving each person the latest Ford halfshaft hardware kit for them to keep as a back up should there ever be a failure with the AccuFab hardware which I suspect is remote.

Now after we go through a full season of activities with these gals that have the latest halfshaft hardware installed my feelings may change however for now the only halfshaft hardware that I install is AccuFab's.

FYI: I have no ties to AccuFab other than I use their products.

All the best

Shadowman
 

Accufab

Well-known member
Mar 14, 2006
142
Appreciate the testimonial, Shadowman. To be honest, Accufab wasn't interested in getting into the bolt business. This was also true about other Accufab products for the GT (the air inlet support and the coolant hose supports). We wound up backing into offering these products only because customers were having problems in these areas, and we had enough GT dyno time to witness these problems for ourselves. None of the fixes were any rocket science. We saw a problem and created a solution, no big deal really. Isn't that what hot rodders have been doing for the last 50 years? In my opinion, there was no reason why Ford couldn't have done the same thing, and in a timely manner. Why they didn't is a mystery to us here at Accufab.
 
Aug 25, 2006
4,436
Appreciate the testimonial, Shadowman. To be honest, Accufab wasn't interested in getting into the bolt business. This was also true about other Accufab products for the GT (the air inlet support and the coolant hose supports). We wound up backing into offering these products only because customers were having problems in these areas, and we had enough GT dyno time to witness these problems for ourselves. None of the fixes were any rocket science. We saw a problem and created a solution, no big deal really. Isn't that what hot rodders have been doing for the last 50 years? In my opinion, there was no reason why Ford couldn't have done the same thing, and in a timely manner. Why they didn't is a mystery to us here at Accufab.

You are welcome

Now to the "why" regarding Ford I can only speculate as such I will not chime in other than to say "Thank You Ford" for continuing the quest for the final solution however to my feelings about the hardware as presented by you and your team I will share the following;

Once I install your hardware system on my own gal the peace of mind alone was worth far more than the price of admission. Then add to this evey time I have installed your hardware system on another's I always consider the project finished rather than pending as such the secondary peace of mind is even greater.

Keep up the great work

Takes care

Shadowman
 

DBK

The Favor Factory™
Staff member
Le Mans 2010 Supporter
Jul 30, 2005
14,707
Metro Detroit
I have the Accufab bolts and will not be changing them out for the new ones. As stated, I have never heard of a single bolt breaking.
 

06fordgt

GT
Mark II Lifetime
Le Mans 2010 Supporter
Nov 8, 2006
1,843
Toronto Canada
Rec'd my letter from Ford Canada. Interesting to note the letter only refers to 2006 cars not 2005 cars.
Besides some minor layout and format differences from what I've seen posted here the other real difference is the Ford "Customer Relationship Centre" and phone number 1 800 565 3673.
Since I've already had the failutre and used the Accufab fix, I wll now attempt to get the refund for the work done.
 

MAD IN NC

Proud Owner/ BOD blah bla
Mark IV Lifetime
Feb 14, 2006
4,174
North Carolina
GET YOUR NUTS AND BOLT's CHECKED! Program 07B49

Just got back from the dealership where they changed by halfshaft bolts! Thanks for this dealership and the work Coy (service writer) and Grahm (mechanic) just did being at Don Jenkins in Fuquay Varina NC.

SCARY:eek ~15 months ago for peace of mind I had them replaced. At that time the "shiny" original washers were cupped and failure was possible.

Today when I looked at them the washers were they gray type - not cupped but one bolt head on the passenger side broke off just by putting the socket and allen on it!. Two others broke off during de-install and only one came out without the head shearing off. I'M GLAD I WENT TODAY! I was destined to be road kill!

The first picture is the old passenger side. The bottom "washer" is the Loctite between the washer and the halfshaft itself. file = pass

The last picture is the new washers and bolts! file = new

The old "original" washers were 6.05 mm thick. The new 07B49 washers are 13.5MM thick with two insets of ~6.45MM for the bolts. My insurance set of Accufabs are 7.6MM thick (Anybody want to buy a set of new Accufab bolts? - just kidding. I will keep them as I have not heard they have ever failed yet).

So - RUN, don't walk! Get them bolts changed! It's worth the 4 hr's.

Thanks Jamal!
 

Attachments

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
3,626
Ford's Latest Halfshaft Repair vs Accufab

Well, today was "Ford GT Halfshaft Bolt Upgrade Day" for Ryan and I. George invited us over to perform the Accufab upgrade on both of his fine machines. This was approximately the 19th & 20th upgrade we have done and it was a good workout as we rolled each car back and forth to get access to each of the outer bolts. (We realize how spoiled we are to have the lift back at home!) It took us about 3 hours to get both cars done and on the way home, I got a call from my local dealer informing me that my Ford upgrade had come in.

We drove over and picked up the kit and I took some pictures of the latest Ford Kit compared to an Accufab kit. I believe Forum members may be interested in seeing the differences.... and perhaps even my opinion(s).

Both the accufab and Ford kit now provide the (6) outer flange bolts. why ford did not include these in their first kit remains a mystery to me, but kudos to Ford for doing it right this time around. The Ford kit includes a new set of the exact same, T-50 TORX outer bolts that you will remove per side. The Accufab kit includes some very pretty ARP 12-pt bolts that are also drilled for thse that would prefer to wire them. (Unnecessary, in my opinion.) The outer bolts have never been an issue so I didn't bother with any pictures.

This first picture is the Accufab Kit inner washer and bolts (on the left) and the Ford inner washer and bolts (on the right).



There's a big difference in the thickness of the washer as depicted in the following pictures. The new Ford washer is much thicker and has been recessed to allow the inner bolts to drop in. The recess is necessary because the top of the bolts even in the original set-up almost come into contact with the dust cap of the CV joint at the end of the halfshaft.







What was REALLY interesting for me is that the new Ford washers are the exact diameter as the Accufab's - which are significantly larger than both of Ford's previous washers. In a one-on-one conversation with a rep from Ford, I know that they were originally "concerned" about the diameter of the Accufab washers, so I'm glad to see that there must now be agreement!





Here's a comparison of the inner bolts. The ARP bolts in the Accufab kit are still the best, IMO.







The Ford kit looks real good and I assume it will resolve the problems we have been having. I still prefer the Accufab kit because I believe the bolts are still superior. I have not and still do not believe that the embrittlement theory is the full explanation and there are very complex forces acting on the bolts. The stronger bolts supplied in both kits may be enough to withstand these forces, but I'm going to opt for the best bolt manufacturer in the world - which is ARP.
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,403
Greenwood, IN
Great Pictures!

Kendall-
Great post and thanks for the comparative hardware pictures of both kits! Your attention to detail and observations are what make this Forum a great clearing house of information.
I agree with you both kits will solve the previous bolt breaking problem and that ARP is in my opinion (also) the best source of premium fasteners. Whichever route an owner opts for, the issue will go away.

I do have to comment on your statement, "I have not and still do not believe that the embrittlement theory is the full explanation and there are very complex forces acting on the bolts. The stronger bolts supplied in both kits may be enough to withstand these forces, but I'm going to opt for the best bolt manufacturer in the world - which is ARP." Ok, what do YOU think is the failure mode of the bolt?

I am told by reliable internal sources, many of the warrantied failed bolts which were returned to Ford engineering were carefully metallurgically examined. It is pretty easy to see the "beach marks" on the fractrue surface indicating a fatigue failure but what neucleates the crack origin? Because of the failure publicity (and the first fix not correcting the problem) the team inspected every aspect of what failure mode was breaking the bolt. A lengthy and time consuming process but one, given the gravity of the situation, was necessary. Obviously this entailed insitu strain gauge testing of the bolts during an agressive driving cycle. Thus the "complex forces acting on the bolts" was fully characterized and I'm told the maximum loading was nowhere (let me repeat, NOWHERE) close to the bolt tensile strength of an M8 bolt. Thus this is not a bolt STRENGTH issue.

I realize this is the "easiest" explaination for laypeople to grasp because most all of us have an idea of how things break when they are overloaded. Higher order failures like fatigue, metallurigical defects, hydrogen embrittlement, residual machining surface stress, hard alpha inclusions, etc. are difficult to understand and best left to the engineers to sort out.

Again, Kendall, I appreciate your comments! I am just glad all owners have two good options to fix our cars and remove the fear of an on-the-road half shaft bolt failue.
 

BIGFOOT

GT Owner
Jan 18, 2012
686
Northeast
If a dealer did the recall in Feb 2008 can we determine if the parts were “bad batch” or “wrong washer” by date alone?
It’s on the Oasis dated Feb 08
Thnx
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,403
Greenwood, IN
Paul,
Good question. I will volunteer my thoughts although I am not so sure of the design evolution of the washer as I am about the bolts.

The early (I believe silver in color) washers were noted to have a perminent cup or "set" when the team started looking at the returned failed hardware. This was unexpected. I summarize hardness tests led to the conclusion the washers were not properly heat treated (increases washer strength), bent or cupped under initial bolt load during the torquing procedure and led to subsequent bolt load relaxation.

Typical bolted flange design is to specify as high a bolt preload as possible (within the material limits of the bolt but usually 90% of TYS, although some fasteners are torque-to-yield which thus exceed TYS) with the objective to never allow the bolt load to relax. Flanges with little or no preload are predisposed to failure with the flange sustaining anything more than a constant load. Consideration must also be given to the relative stiffnesses of the mating flanges and considerations for thermal expansion. This drove the early focus to an inferior washer. Thus the first fix was a stronger (heat treated) washer and the same bolts. Obviously as failures continued, this was not the correct answer and the team went back-to-the-drawing board to actually determine the "root cause" of the failure. This is what takes TIME.

The installed bolt head clearance with the CV is minimal and though not shown in Kendall's pictures I belive the ARP bolt heads (from the bolt bearing surface to the top of the head) are slightly longer than the OEM bolts. I believe the clearance is important to maintain and thus the OEM kit counter-sinks the bolts into a new even thicker and stronger washer to maintain clearance. It is my guess that a "new" washer design was already under way when the second evolution black unit washer was found to again be failing bolts. The team did their due dilligence, determined the hydrogen embrittlement problem with the bolt, sourced a new bolt to remove the problem and went with the third generation thick washer even though the bolt (not the washer) was found to be the root cause.

At least that's what I think happened. (And I do not work for Ford, thus just opining.)
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
10,183
Belleville, IL
If I remember correctly, if you got the "bad" update, you went back in and got the "latest" update. I would think there would be Two oasis reports.
 

twobjshelbys

GT Owner
Jul 26, 2010
5,170
Las Vegas, NV
If I remember correctly, if you got the "bad" update, you went back in and got the "latest" update. I would think there would be Two oasis reports.

I interpret the question as there is one updated in Feb 2008 and the question is was the replacement with the bad or good parts. Were there separate part numbers?

I asked the same question when Rich had my car. The Oasis report on mine was May 2008 and references recall #07B49. Rich assured me this was the second pass.

This thread:
http://www.fordgtforum.com/forums/showthread.php/29979-Half-shaft-moves?highlight=07b49
says there is a way to tell: The bad parts had allen screw heads, the updated had hex-head bolts.
 
Last edited:

BIGFOOT

GT Owner
Jan 18, 2012
686
Northeast
^^
Correct
Just a single Oasis saying done in Feb of that year.
Nothing more.