Halfshaft Bolt Failures and Customer Satisfaction Program


nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
3,600
Today, they extracted 3 bolts on one side, 1 bolt on the other side, and are using the 4G7Z-4B490-A for both axles and removing and replacing all bolts and all washers
Randy, sorry to read about your misfortune. Don't worry as I am sure all will be better soon. Your tech may be very competent. Having done dozens of axle bolt upgrades, I offer the following:

1. As there are only two axle bolts per side, I assume it was a typo above to indicate that 3 bolts were extracted on one side. :eek
2. Tech should re-tap holes and with the tap, thread depth should be checked. We've seen cars with nice threads but where there was significant loc-tite build up at the end of the hole. If not checked and corrected, the new bolts can give a false torque reading where they are actually bottoming instead of tightening against the new washer. Only 1 car in 10 will have this build-up, but 10 cars in 10 should be checked for it prior to assembly.
3. As a precaution and as long as you're "in there", I would highly recommend following TSB 05-10-13. In short, I would advise that immediately before installing the washer, clean the surface immediately behind the washer which is the end of the splined output shaft. (Transaxle fluid will have a tendency to seep down the splines and into the coupling.) With this surface cleaned, you can smear some black RTV around the perimeter of splined axle surface before installing the washer and new axle bolts.
4. It is very important to follow proper torque procedures. There are too many mechanics who have convinced themselves that they have a torque wrench build into their elbow. Don't let this happen.
5. The outer bolts around the coupler also have a specific 2-step torque procedure. This can be done more efficiently if the tire is slightly lifted from the ground so that the axle can be rotated into positions where the to-be-torqued bolt can be accessed with the torque wrench. If the bolts are not numbered prior to doing this process, you are virtually assured of straying from the procedure.
 

SYCO GT

GT Owner
Mark II Lifetime
Sep 9, 2006
4,258
California
1. As there are only two axle bolts per side, I assume it was a typo above to indicate that 3 bolts were extracted on one side.
I thought it was a package of 12 bolts, or 6 bolts per side.

Info was from Service Advisor, I will verify with tech. Thanks.

UPDATE: Tech says it was 2 bolts on each side sheared, he removed one, and specialist removed the 3 others.
 
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Empty Pockets

ex-GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Oct 18, 2006
1,249
Washington State
However I only install the AccuFab/ARP ............... they are not torque to yield bolts as such will allow for future service without replacement needed.

'Best argument in support of Accufab's bolts there is. Well, that and the fact that there's NEVER been a reported Accufab bolt failure. EVER.

'Sorry to hear about your pblm, Randy. 'Gotta be a total pain...


(As an aside, Wifey & I just returned from 'Vegas, so, I thought I'd go to The 'Forum to "catch up"...and krymuny! I see we're discussing those darn 'BOLTS again!!!:lol I thought for a moment I'd entered a dang time warp or something!)
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
3,600
Hi Randy,

I have attached a diagram to help you to understand what is going on. The bolts that fail are indicated by the "1". These are the bolts that would need to be extracted. To date, I haven't seen a case where the bolts break flush (therefore requiring drilling and extraction), but I'm sure it can happen. It is more typical on a failure that only one of the two bolts would break. Further, there has NEVER been a case where both sides of the car have failed simultaneously. So, the worst case scenario is that you dealer is needs to "extract" 2 bolts, but much more likely, only 1. If he is saying something other than this, well...

The GT's half-shaft mates with "Output Shaft Flange (3)" using 6 bolts around the perimeter. There has NEVER been a reported case of these bolts breaking. These outer (6) bolts, as Shadowman has stated, are TTY (torque to yield) bolts and should be discarded instead of re-used. The new Ford kit comes with these 6 new bolts - exact replacements so that they too, can only be used once. This is the reason that Shadowman and myself prefer the Accufab (ARP) bolts - so that the coupler can be disassembled at any time and for any reason.

Not shown in the picture is the flanged shaft that protrudes from the transaxle and that the flanges of the "Output Shaft Flange (3)" engage with. The flanges on the "Output Shaft Flange (3)" can be seen and the "Output Shaft Washer (2)" sits flush (almost) with the end of the output shaft (not depicted) and the "Output Shaft Flange (3)". This is the area I referred to in the TSB where transaxle fluid can weep down the flanges and out from underneath the waser. The TSB describes the remedy for this. I know that as a matter of practice, Cool Tech, the GT Guys, and I suspect Shadowman, all address the TSB at the time of re-assembling these parts. Not to toot anyone's horn, but this is the techniques that come from experience whereas a competent but otherwise "GT inexperienced" mechanic can overlook these "tricks".

Don't hesitate to call if you have any questions.
 

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SYCO GT

GT Owner
Mark II Lifetime
Sep 9, 2006
4,258
California
Thank you Kendall that is very helpful and appreciated.
 

SYCO GT

GT Owner
Mark II Lifetime
Sep 9, 2006
4,258
California
Update: I wanted to let everyone know that I have my Ford GT back in my possession, with the proper and current parts package used 4G7Z-4B490A installed, properly torqued with tools (not elbow) and road tested.

Ford and the Dealership have stepped up to the plate, and after much research and discussions, I am in a good place, and back to fully enjoying my cherished GT again.
 

BlackICE

GT Owner
Nov 2, 2005
1,412
SF Bay Area in California
Great news! :thumbsup
 

PL510*Jeff

Well-known member
Mark IV Lifetime
Le Mans 2010 Supporter
Nov 3, 2005
4,618
Renton, Washington
That's great news.:thumbsup
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
10,149
Belleville, IL
Very good news. Welcome back to the living.
 

GEE-TEE

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
May 1, 2009
563
Calabasas, California
Hi Kendall,

I know you have checked my car as well as this document from the former owner last year. However, this concerns me as the white lines mentioned seem like they were never interupted... I do recall the first time you had my car you said it seems like this was done but what are the chances of me having the same experience of Randy?

BTW Welcome back SYCOGT. This seems like a scarry experience. What if you were going on the freeway at like 80mph and this had happened?
 

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Jan A. Byrd

GT Owner
Aug 21, 2006
39
Percy IL
Mine is one of the last build which was the last of June 06. I took mine to the local Ford dealer and they didn't have any way or thought they didn't have a way to jack it up properly. I'm actually glad they called me instead of trying something stupid and causing damage. I talked them into providing me the parts but requiring me to sign a waver to do the repairs myself. I am 59 and have been a mechanic/autobody tech all my life. I felt more confident in doing the repairs myself vs a wet behind the ears tech at the dealership. The repair took a little time but probably due to myself going slow and double checking my actions. One of the two bolts on the left side was intact but cracked. When I tried to remove the bad bold the head simply broke off leaving the bolt flush with the splined axle end. After much consideration deciding how to remove the broken bolt I purchased a small set of Snap-On reversed drill bits. When the drill bit got a really good hold onto the bolt it started moving out. Lord knows what an inexperienced tech may have tried to get this very hard bolt out.
In our area where I live the roads are very bad from heavy truck traffic. Soon after buying the car I was putting my foot into it after leaving intersections from time to time (now I don't). When the rear tires under heavy acceleration would hit the patch work I believe it caused additional stress on the axle bolts causing premature failure. Anyway this is my story. Jan
 
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BIGFOOT

GT Owner
Jan 18, 2012
685
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
 

fjpikul

GT Owner
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Le Mans 2010 Supporter
Jan 4, 2006
10,149
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
5,084
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.
 
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BIGFOOT

GT Owner
Jan 18, 2012
685
Northeast
^^
Correct
Just a single Oasis saying done in Feb of that year.
Nothing more.
 

nota4re

GT Owner
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Le Mans 2010 Supporter
Feb 15, 2006
3,600
says there is a way to tell: The bad parts had allen screw heads, the updated had hex-head bolts.
Absolutely true.... but you have to disassemble the 6 outer bolts to separate the coupling to see inside. The "new" (correct) kit will have 2 hex head bolts recessed into a very thick (~.75") washer. The OEM and "bad" fix will have allen head bolts NOT recessed.