GT500 Stock Part Failures

JB_2010GT500

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Thought I'd share some of my experiences with stock part failures after having owned the 2010 for 5 1/2 years (better late than never, right?). I told Tob almost a year ago that I would post pics of failed parts once I got around to digging them out of the attic. Hopefully this content is helpful for those of you who drag race your cars. I drag race mine about 3-4 times per year.

First up, the stock two-piece driveshaft (and axles). This was a problem only my third time at the drag strip with the car (back in 9/2010). I was stock with the exception of running Nitto NT05r 305/45 18s at about 18 psi. Launch was consistently a 3,500 sidestep after heating up the radials for a few seconds. Well, my third trip to the strip and the driveshaft had had enough. Went thru staging just fine. When I went to launch, boom, down went the driveshaft. Spectators later told me that the tires never even budged. After towing the car to a local shop, the mechanic also discovered that the axles had bent pretty badly. The bends weren't really noticeable to the naked eye, so I didn't take pictures. Just the driveshaft:

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After this, I added the 1 piece driveshaft (and safety loop) and Moser 31 spline axles. The car made it all the way til 5/2014 when the next part failed upon launching at the drag strip. This time it was the stock upper control arm. My theory is the cheap stamped metal which encases the bushing had elongated over time, and after so many impacts from hard launches, it finally snapped upon launch at the strip. In fact, in the months leading up to the failure, I could hear a banging sound coming from the rear of the car under hard acceleration. I'm assuming the sound was caused by the extra play in the UCA bushing (on the last side-profile pic you can get a good angle of the deformed/out-of-round bushing):

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I upgraded the LCAs in addition to the UCA at this time. Also, I decided to take advantage of the KB 25% off sale and get the stage 3 2.8LC kit (3.25" pulley with stock KB 93 octane tune; this will come into play later). I also got a C&R dual fan HE and a 3x reservoir. My setup was making around 14.5 lb of boost. 7/2014, back to the drag strip. At this point I had given up sidestepping and went to a feathering approach at 3,000 rpm. I had also switched from NT05rs to 305/35 18 MT ET Street IIs because the NT05rs had worn down. After a few passes, my driver side axle tube spun upon launch (I was fortunate that all three drag racing failures happened at the line and not traveling down the track). I didn't take a picture of it since it's pretty self-explanatory. Also, the Moser axle on the driver side had bent ever so slightly. Back to the shop... Good thing I upgraded to AAA Plus. I ordered a full Ford Racing (aka stock) rear end with 3.73s. From my past experience (read above), I immediately had the tubes welded, added a Swarr bar for additional reinforcement, and had Strange c-clip eliminators and 31 spline axles put in.

The final stock part to fail was my catalytic converters. When I purchased the KB 2.8LC kit I was given the impression that I would be fine with my stock exhaust setup. Well, my CEL came on 5/2015 (note the kit was installed 6/2014) with p0420 catalyst efficiency code. I don't have a mileage estimate for the 11 months from installation to cat failure but I can try and dig thru my records and follow up with one. Here are some pics of the stock cats along with the material that fell out of one of them :):puts on flame suit::
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The final stock part I've had start to fail was the stock clutch, and it just happened this month. I'm currently just under 19,000 miles on the clutch. I was at ~550 whp on a Mustang dyno with the prior setup, which apparently my stock clutch was able to handle for 11 months. After finding out that I needed a new exhaust system, I went with a Dynatech LTs, a Dynatech catted x-pipe, and MBRP 3" exhaust. For good measure, I also had ID1000s, a 3" pulley, and TR 7IX plugs put in. Made 633 whp on the Mustang dyno with 93 octane (hoping to post a thread with dyno graphs and data at a later point in time). Needless to say, the clutch couldn't handle the extra 80+ whp on the street as it started slipping. Anyways, somewhere >550 and <630 whp on a Mustang dyno was my stock clutch's inflection point, and I'm sure there are several factors that determined it, not just whp.

Hopefully I won't be updating this thread down the road!
 

ShelbyGT5HUN

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Good read. I'm a little shocked by the driveshaft failure. Seems like a lot of people here run a pulley, tune, and drag radials, yet I don't read about a lot of driveshaft and axle failures, at 550rhwp levels. Those components are usually the last things people upgrade, or even think about upgrading at all!

The cats are a known weak point, lucky you didn't fry a piston over a failed catalytic convertor.
 

JB_2010GT500

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Good read. I'm a little shocked by the driveshaft failure. Seems like a lot of people here run a pulley, tune, and drag radials, yet I don't read about a lot of driveshaft and axle failures, at 550rhwp levels. Those components are usually the last things people upgrade, or even think about upgrading at all!

The cats are a known weak point, lucky you didn't fry a piston over a failed catalytic convertor.

The broken driveshaft and bent stock axles occurred back in 9/2010 when my motor was bone stock. I'm guessing it was a combination of spending too much time heating up the tires and side stepping the clutch that did them in.

Also as a follow-up on the mileage: I went thru my records and the stock catalytic converters lasted approximately 2,000 miles (11 months) with the out-of-the-box Kenne Bell stage 3 kit, which was running a 3.25" pulley (about 14.5 psi) and 93 octane tune.
 

Tob

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John, the best part about this thread is your attitude. You've remained completely objective and didn't run off onto an opinionated rant about how lousy these cars really are. You simply addressed each failure and moved on to the next one. Huge thanks for that.

And I thank you for documenting each failure mode so well. We've all seen the factory driveshaft fail (in photos, that is) and the mode there is rather consistent, just where the tubing diameter abruptly changes. What is interesting is that you were at such a relatively low power number when it happened, albeit with some sticky rubber and what sounds like a pretty brutal launch technique.

The upper control arm failure is fascinating. The base material looks to have yielded at the heat affected zone from weldment. I've never seen one tear that way but it makes sense given the soft bushing/deflection and the conditions it was under. Immediately made me think of the Roush upper and the added strap that wraps around this area and ties it back to the main arm for additional strength.

The material in your cat failure doesn't look like substrate but rather the matting that is sandwiched between the substrate and the outer shell. Is there something we aren't seeing such as material that blew out from one side to the other (or further downstream in the exhaust)? Doesn't look like the typical "meltdown" failure we see every now and then.

The axle and clutch failures are fairly typical, including the spun tube. As you mentioned, good to hear you weren't at speed when they gave way.

Huge thanks for documenting all of this in an organized and articulate manner John. Looks like you have a knack for finding weak points yet still remain level headed about it. I hope you're nearing a point where you can reliably abuse the car without having to continually fortify it.

Superb thread.

Tob
 

JB_2010GT500

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Thank you very much, Tob. I felt it was time to give back after I had learned so much thru these forums. Maybe I should make a thread dedicated to failed aftermarket parts as well :eek:. I like to document and collect facts as much as possible, even when I don't even fully understand them when it comes to the car. I learned the hard way not to do the rev/dump launches, for sure. Funny how there are always keyboard and bench racers willing to say "just rev it up and dump it!".

I did notice symptoms of the catalytic converters failing prior to the CEL. First, I noticed that the exhaust note had gotten louder and raspier. I also could smell it. Finally, once the CEL came on, I had someone rev the engine a bit while I watched little metallic specs appear to fly out the exhaust. Not sure what that material was and not 100% certain the specs were even coming out of the exhaust (there's a chance they were sand particles being kicked up from beneath the exhaust tips). I wasn't able to peek into the back side of the catalytic converters since the pipes have bends in them. Could it possibly be that there are some remains of the catalytic converters caught in the muffler chambers?
 

sono

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The drive shaft is classic!
Big thick peace of steel wadded up like A chewing gum wrapper.

Must have launched like a buffalo gun!
 

RedVenom48

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+1 for the awesomeness of the GT500 tech forums. Such a wealth of information!

First to be modified on my car was the shifter after the trans got repaired. Next, the rear suspension to get it ready for real launching. Then the engine mods after the fine folks at Kearny Pearson Ford figured out her misfire issue. Added some sticky tires (NT05Rs) and did 2 drag events. 1st being a "track" at the Charger's football stadium. Spin city, but fun. Second time out was to Barona Drag way and holy moly, I finally found grip! ...and instantly knew at the end of my night I had to get an upgraded driveshaft.

Launching at 3000 RPM (probably going to have to go to 3500 with my new M/T setup out back) I knew the stock DS wasnt going to last. Today Im installing a DSS aluminum shaft and BMR rear chassis brace with integrated safety loop.

Next after that will be a McCleod RXT clutch as all this abuse wont let the stocker last much longer Im sure. Even with all this upgrading, we still got a hell of a car from the factory. After mods, our cars are just that much f'n better.

All because of the knowledge from this board. Glad I joined! :)
 

JB_2010GT500

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Thanks lexustech48; good luck with your mods! I love my McLeod!

Tob--sorry if I wasn't clear in my description. I meant that I had small bright metallic flakes possibly flying out of my exhaust. Similar to what this GT500 owner described here: http://www.teamshelby.com/forums/index.php/topic/27594-metal-shavings-from-exhaust/

After reading thru that, it also reminded me that I did have quite a bit of smoke blowing out at WOT. I would love to dissect the cats and mufflers to see if there are any other remains. I've kept every stock part from the car (I even have the complete original rear end taking up space in the garage) just to have down the road. If I could source another stock 2010 exhaust (just for completeness), I'd be open to doing an autopsy of my cats and mufflers.

EDIT: I went thru my phone and dug up two photos I took of the muffler tips. You can see clumps of tiny flakes. Again, can't be 100% sure they came out of the exhaust but they looked pretty suspect:

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JB_2010GT500

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Autopsy!:rockon:

I'm with you on that. I will keep hunting for a 2010 stock exhaust (would need it if I ever put the car back to stock anyways), and if I get one I'll break out the saws-all!

The 2010 exhaust is the hardest to find for the GT500 since the exhaust was unique to that just that one model year, vs the '07-'09, '11-'12, and '13-'14.
 

RedVenom48

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Those particles in your exhaust look a lot like blown out converter media to be honest
 

JB_2010GT500

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My PB on the stock motor with just drag radials was 12.3 @ 114. Never got a good test of the true potential of the out-of-the-box KB stage 3 kit as the car always seemed to have an issue at the strip (spun axle tube, clogged cats, loose driveshaft bolts, etc.). However, the runs I did get were consistently 12.0/12.1 and 122ish MPH. And that was basically from a roll.
 

brandonflood123

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JB when you say spun tube what do you mean? sorry for the noob question, i drive a 2010 aswell, its all stock 34k miles ( i got it with 9k) and ive had no issues besides the 1-2 grind. i have purchased a 2.9 whipple, longtubes with offroad X, jlt 127 CAI, BAP and ID725s aswell as the Mcloud RXT and MGW Gen 2, i have not put any of the parts on yet, and wanna make sure that when i do i dont have any crazy failures.

already have upper and lower control arms on the car installed( BMR).
 

JB_2010GT500

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No problem. If you look at your rear differential housing you can see on both sides that the axle tubes are pressed inside of it. This concept of a press fitting means that the outside diameter of the axle tube is actually slightly larger than the diameter of the housing holes that the tubes fit into. As such, this requires that a machine presses the tubes into the differential housing. The tubes are not fastened to the housings in any other way other than the press fitting (eg, no bolts, etc.). Under normal situations, the tubes remain fixed because they are under a high amount of compression (picture trying to twist a cork inside an unopened bottle of wine). However, if you do a hard launch on the car but the tires don't break free, the torque may transfer through the axle tubes and physically spin them free from the differential housing. A common solution is to weld the axle tubes to the differential housing. I'm sure if you google search welded axle tubes you'll find tons of examples.
 

1320 Junkie

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Man your brave dropping the hammer with that driveshaft in there. I yanked mine out as soon as I broke into the 11's bone stock...I was terrified of what happened to yours happening to mine. Glad no parts failures did any serious damage to you or the car.
 

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